Roman Period “megadrought” found in the USA southwest

From the University of Arizona, one wonders how such a thing could happen when CO2 was at “safe” levels. They are using bristlecone pines again, which may very well be a better proxy for rainfall than for temperature. At least there was no competition bias from sheep ranching then. It seems they also confirmed a drought in the medieval warm period in the 12th century.

UA scientists find evidence of Roman period megadrought

A new study at the University of Arizona’s Laboratory of Tree-Ring Research has revealed a previously unknown multi-decade drought period in the second century A.D.

IMAGE: Dendrochronologists extract a small, pencil-shaped sample of wood from a tree with a tool called an increment borer. The tiny hole left in the tree’s trunk quickly heals as the…Click here for more information.


Almost nine hundred years ago, in the mid-12th century, the southwestern U.S. was in the middle of a multi-decade megadrought. It was the most recent extended period of severe drought known for this region. But it was not the first.

The second century A.D. saw an extended dry period of more than 100 years characterized by a multi-decade drought lasting nearly 50 years, says a new study from scientists at the University of Arizona.

UA geoscientists Cody Routson, Connie Woodhouse and Jonathan Overpeck conducted a study of the southern San Juan Mountains in south-central Colorado. The region serves as a primary drainage site for the Rio Grande and San Juan rivers.

“These mountains are very important for both the San Juan River and the Rio Grande River,” said Routson, a doctoral candidate in the environmental studies laboratory of the UA’s department of geosciences and the primary author of the study, which is upcoming in Geophysical Research Letters.

The San Juan River is a tributary for the Colorado River, meaning any climate changes that affect the San Juan drainage also likely would affect the Colorado River and its watershed. Said Routson: “We wanted to develop as long a record as possible for that region.”

Dendrochronology is a precise science of using annual growth rings of trees to understand climate in the past. Because trees add a normally clearly defined growth ring around their trunk each year, counting the rings backwards from a tree’s bark allows scientists to determine not only the age of the tree, but which years were good for growth and which years were more difficult.

IMAGE: A cross section of wood shows the annual growth rings trees add with each growing season. Dark bands of latewood form the boundary between each ring and the next. Counting…Click here for more information.

“If it’s a wet year, they grow a wide ring, and if it’s a dry year, they grow a narrow ring,” said Routson. “If you average that pattern across trees in a region you can develop a chronology that shows what years were drier or wetter for that particular region.”

Darker wood, referred to as latewood because it develops in the latter part of the year at the end of the growing season, forms a usually distinct boundary between one ring and the next. The latewood is darker because growth at the end of the growing season has slowed and the cells are more compact.

To develop their chronology, the researchers looked for indications of climate in the past in the growth rings of the oldest trees in the southern San Juan region. “We drove around and looked for old trees,” said Routson.

Literally nothing is older than a bristlecone pine tree: The oldest and longest-living species on the planet, these pine trees normally are found clinging to bare rocky landscapes of alpine or near-alpine mountain slopes. The trees, the oldest of which are more than 4,000 years old, are capable of withstanding extreme drought conditions.

“We did a lot of hiking and found a couple of sites of bristlecone pines, and one in particular that we honed in on,” said Routson.

To sample the trees without damaging them, the dendrochronologists used a tool like a metal screw that bores a tiny hole in the trunk of the tree and allows them to extract a sample, called a core. “We take a piece of wood about the size and shape of a pencil from the tree,” explained Routson.

“We also sampled dead wood that was lying about the land. We took our samples back to the lab where we used a visual, graphic technique to match where the annual growth patterns of the living trees overlap with the patterns in the dead wood. Once we have the pattern matched we measure the rings and average these values to generate a site chronology.”

“In our chronology for the south San Juan mountains we created a record that extends back 2,200 years,” said Routson. “It was pretty profound that we were able to get back that far.”


IMAGE: Doctoral candidate Cody Routson of the environmental studies laboratory at the University of Arizona’s department of geosciences scrambles up a mountain slope to sample a bristlecone pine tree. Click here for more information.


The chronology extends many years earlier than the medieval period, during which two major drought events in that region already were known from previous chronologies.

“The medieval period extends roughly from 800 to 1300 A.D.,” said Routson. “During that period there was a lot of evidence from previous studies for increased aridity, in particular two major droughts: one in the middle of the 12th century, and one at the end of the 13th century.”

“Very few records are long enough to assess the global conditions associated with these two periods of Southwestern aridity,” said Routson. “And the available records have uncertainties.”

But the chronology from the San Juan bristlecone pines showed something completely new:

“There was another period of increased aridity even earlier,” said Routson. “This new record shows that in addition to known droughts from the medieval period, there is also evidence for an earlier megadrought during the second century A.D.”

“What we can see from our record is that it was a period of basically 50 consecutive years of below-average growth,” said Routson. “And that’s within a much broader period that extends from around 124 A.D. to 210 A.D. – about a 100-year-long period of dry conditions.”

“We’re showing that there are multiple extreme drought events that happened during our past in this region,” said Routson. “These megadroughts lasted for decades, which is much longer than our current drought. And the climatic events behind these previous dry periods are really similar to what we’re experiencing today.”

The prolonged drought in the 12th century and the newly discovered event in the second century A.D. may both have been influenced by warmer-than-average Northern Hemisphere temperatures, Routson said: “The limited records indicate there may have been similar La Nina-like background conditions in the tropical Pacific Ocean, which are known to influence modern drought, during the two periods.”

Although natural climate variation has led to extended dry periods in the southwestern U.S. in the past, there is reason to believe that human-driven climate change will increase the frequency of extreme droughts in the future, said Routson. In other words, we should expect similar multi-decade droughts in a future predicted to be even warmer than the past.

###

Routson’s research is funded by fellowships from the National Science Foundation and the Science Foundation Arizona. His advisors, Woodhouse of the School of Geography and Development and Overpeck of the department of geosciences and co-director of the UA’s Institute of the Environment, are co-authors of the study.

194 thoughts on “Roman Period “megadrought” found in the USA southwest

  1. “Dendrochronology is a precise science of using annual growth rings of trees to understand climate in the past”
    “What we can see from our record is that it was a period of basically 50 consecutive years of below-average growth,” said Routson. “And that’s within a much broader period that extends from around 124 A.D. to 210 A.D. – about a 100-year-long period of dry conditions.”
    ===================================================
    …or about a 100 years long period of below normal temperatures

  2. This is in line with Mann’s statements that global warming would lead to more droughts and hurricanes in the Southwest. The other implication is that warming from carbon dioxide will produce more LaNina’s, giving a negative feedback that lowers the overall global temperature. This is the reason that Mann says there was no Medieval Warm Period, that the tropics had LaNina like effects. When asked if this meant a negative feedback and models were vastly overstating warming, he said I agree with that… I think there’s a missing negative feedback.

  3. Sneaky buggers. Here I thought I was reading about some actual science being done, and then they had to spoil it right at the end with their manmade climate crapola.
    Still, I suppose it was a requirement to pay the obligatory lip service to the CAGW meme for funding. Science in the service of ideology, how refreshing.

  4. If they had narrower tree rings, doesn’t that mean instead that it was colder?
    MBH 98 said so.
    How did this get past Professor Hughes?

  5. >>
    Although natural climate variation has led to extended dry periods in the southwestern U.S. in the past, there is reason to believe that human-driven climate change will increase the frequency of extreme droughts in the future, said Routson.
    <<

    In climate science, you always have to add a hat-tip AGW.

    Jim

  6. They wasted money to find something that was already known. The times they are talking about are known transition periods from warm to cold. Maybe they should have studied historical climate records first!

  7. Although natural climate variation has led to extended dry periods in the southwestern U.S. in the past, there is reason to believe that human-driven climate change will increase the frequency of extreme droughts in the future, said Routson. In other words, we should expect similar multi-decade droughts in a future predicted to be even warmer than the past.

    Based on what reasoning? Naturally Routson needed that CYA statement to get past CAGW censors. After all, his research was funded by the NSF.

  8. that doctoral candidate should be advised that Rio means River, thus there is no Rio Grande River.

  9. MikeN says:
    November 4, 2011 at 4:50 pm
    This is in line with Mann’s statements that global warming would lead to more droughts and hurricanes in the Southwest.
    ———————
    Mike, isn’t this like a “one for one” in that for every hurricane you get don’t you lose one drought?
    It sounds like Dr. Mann is covering his ……………..bases.

  10. Latitude says:
    November 4, 2011 at 4:42 pm

    “Dendrochronology is a precise science of using annual growth rings of trees to understand climate in the past”
    “What we can see from our record is that it was a period of basically 50 consecutive years of below-average growth,” said Routson. “And that’s within a much broader period that extends from around 124 A.D. to 210 A.D. – about a 100-year-long period of dry conditions.”
    ===================================================
    …or about a 100 years long period of below normal temperatures

    ___________________________________________________________________

    Or 100 years of lack of fertilizer from animals.

  11. There is so much to take from every pithy comment so far!!!
    How come the researchers didn’t make any connection between the Roman and Medieval Warm Periods to their drought induced tree rings (if it wasn’t cold, that is, that immediately followed!)? Why does it somehow indicate it has something to do with AGW or CO2 in the future when neither of those things were mitigating factors in the past?
    Statements such as this just make me want to throttle somebody and yell into their faces, “Get a clue, dumbass!!”

  12. I have tracked down a ream of papers on the local paleoclimate, all of which confirm these findings of droughts for the Southwest during the warm periods…the Medieval Optimum, the Roman Optimum, and the entire first half of the Holocene.

    Here in the Eastern Sierra, there have been three major climate regimes in the recent past…the last glacial, the first half of the Holocene, and the present climate.

    Although in the last ten years winter, spring, and fall temperatures have fallen 10F, and precipitation has increased ~150%. Summers have cooled a few degrees. If this weather becomes the new norm, I suspect the climate may shift to that of the previous glacial.

    Wonder how long that takes?

  13. MikeN,

    yes, extreme weather events happened in the past and will probably happen again. Mann’s bloviating shows that he simply wants to try and assign blame to his preferred cause if one does happen in the near future!! Unfortunately he has no mechanism and no studies to back up his mouth.

  14. “During that period there was a lot of evidence from previous studies for increased aridity, in particular two major droughts: one in the middle of the 12th century, and one at the end of the 13th century.”

    For more information about the societal effects of these droughts, I found a couple links that are well worth reading.

    http://www.thefurtrapper.com/anasazi.htm : The unraveling of the Chaco society began with a drought in 1130 A.D. Lack of rain depleted the storehouses and made the farmers question the power of the Chaco priests. The Chaco Phenomena was over.

    http://www.thefurtrapper.com/mesa_verde.htm : After 1150 A.D., the Mesa Verde area of the San Juan Basin had the largest number of people in the Southwest. Increases in the number of people in cliff dwellings reduced the inhabitant’s ability to raise enough agriculture products to feed themselves. Around 1276, a long drought began that continued until the end of the century. Even without a drought, trying to raise enough food on the mesas and getting water out of the canyons played a big part in the abandonment of the Four Corners area

  15. “What we can see from our record is that it was a period of basically 50 consecutive years of below-average growth,” said Routson. “And that’s within a much broader period that extends from around 124 A.D. to 210 A.D. – about a 100-year-long period of dry conditions.”
    ========================================================
    Unfortunately, It looks like they used the official UofArizona 2000 year temp reconstruction, which show the Mann hockey stick. Looking at that, they didn’t see anything in the temp record, so looked for something else…..and called it a 50 year drought….within a 100 year period of slower growth….

    If they had looked at other 2000 year temp reconstructions, they would have seen that 50 year low spike in temps…..

    So was it drought? cold temps? combination of both?………….we’ll never really know.
    Dendrochronology is a precise science……………….

  16. “And the climatic events behind these previous dry periods are really similar to what we’re experiencing today.”

    Far from it. From glacial advance in Sierra Nevada, and the Alps and Norway from the early 2nd century, you can be sure this was a cold period: http://www.geo.arizona.edu/palynology/geos462/holobib.html
    As for the 12th century, there were very cold periods in the 1120`s, 1140`s and 1170`s, as can be seen in these English records:

    http://booty.org.uk/booty.weather/climate/1100_1199.htm

    and accounts from Syria:

    http://syrcom.cua.edu/Hugoye/Vol3No2/HV3N2Morony.html

  17. “It seems they also confirmed a drought in the medieval warm period in the 12th century.”

    Would that be the Medieval Warm Period that supposedly never existed?

    Did any heads explode while researching this? Inquiring minds, etc. . . .

  18. This is new??? I guess when the propagandists whant to respin old knowledge to swerver there anti-human ends, they have to claim that it is new knowledge.

  19. Mike Davis says:
    November 4, 2011 at 5:09 pm

    They wasted more money because Cook and others already did that study, and found the Southwest Megadrought that extended clear into Mexico.
    Not only that, but when you compare instrumental readings with tree rings from the same area, the temperature does NOT correlate well (it’s very poor), but does a much better job when compared to precipitation.
    Still at it wasting taxpayer money, which NSF gets from the Fed. Govt.
    When are these climate gurus going to get it that climate has 4 states, not 2?

  20. Anthony Watts says:

    “one wonders how such a thing could happens when CO2 was at “safe” levels”

    Only if “one” believes that CO­² is the driver for all climate change events, which nobody does. Pointless straw man comments like that do nothing to help the tone of the debate.

  21. Wait…

    They found a drought in North America during the Medieval Warm Period using Bristle Cone Pines? Would that be the same MWP that Mann et al insist was localized to Europe?

    Then, having offended the self appointed demi-g_ds of dendrochronology, who will no doubt demand the resignation of the journal the paper was published in for having failed to consult with “modellers” first, they then spew out this gem:

    Dendrochronology is a precise science of using annual growth rings of trees to understand climate in the past.

    OK, took me a bit to stop laughing. How they untangle temperature, sunlight, CO2 levels, rainfall, soil nutrients, passing fertilizer deposition bio-life forms (goats going poop) from each other from the tree ring data, I’m not certain. That it isn’t precise… of that I am certain.

  22. Why is it that the MWP or RWP or what ever warm period couldn’t be a sign of global warming or cooling according to the hysterical climate-loons, what with global results are affected by, and wholly compiled by, local effects.

    So why is it a big deal for the climate drones that there has been earlier warming that effects the global results if they want current weather events to effect the same global results?

  23. It would have been nice if they could have found some air bubbles in pine gum or some such to measure co2. Can we say from ice cores of these periods or other evidence that co2 was well below todays? The trolls are telling us mann was saying the same thing about warm periods and hurricanes and droughts thinking with such non sequitors we wouldn’t notice that man-made co2 had nothing to do with this. The author also mentioned present warming without mentioning agw warming. Intentional?

  24. Kevin MacDonald says:

    “Only if ‘one’ believes that CO ² is the driver for all climate change events, which nobody does.”

    WHAT??

    CO2 as the primary cause of runaway global warming, climate catastrophe and climate disruption is the central claim of the red faced, spittle-flecked alarmist crowd. Without “carbon” to demonize, what would they have? DDT? Methane? Ozone? Pf-f-f-ft.

  25. “. . . has revealed a previously unknown multi-decade drought period in the second century A.D.

    If this is so, then great! Thanks! We have new information. Someone will search all the literature and soon inform us that, indeed this is new – or not.

    They should have stopped after stating their findings.

    Consider that they and others are still trying to figure out what Earth’s climates have done in the past. They repeatedly find that it changes. This, then, “proves” to them that in the future those climates will change even more (for the worse) because of CO2. Did some places not have better or nicer climates at the same time their place had a drought? That seems to be the case today. Drought in the USA Southwest while the PNW does fine. And, as an example of things not so bad – the current drought in their region is occurring at the same time tropical storm activity (ACE)

    http://policlimate.com/tropical/index.html

    is low.

    Climate is complex. The World is complex. Get used to it.

  26. “The tiny hole left in the tree’s trunk quickly heals as the tree continues to grow.”

    That is false!

    Tree’s NEVER heal.They wall off the injury.To prevent decay from spreading.That is what tree’s do when they are injured.

  27. @Gary Pearse

    Air bubbles trapped in ice or amber or not-yet-amber dried tree resin are known not to be accurate samples of the air at the time they were captured. CO2 and other gasses absorb into the ice or resin, altering the ratios of the gasses from the original.

  28. “These megadroughts lasted for decades, which is much longer than our current drought. And the climatic events behind these previous dry periods are really similar to what we’re experiencing today.”

    So… whatever the cause is now, it is similar to the cause back then?

    Whew. For a moment I thought it was CO2 from human activity. We’re off the hook. Good to know.

  29. Smokey says:

    “WHAT??

    CO2 as the primary cause of runaway global warming, climate catastrophe and climate disruption is the central claim of the red faced, spittle-flecked alarmist crowd. Without “carbon” to demonize, what would they have? DDT? Methane? Ozone? Pf-f-f-ft.”

    CO² is the primary driver of the current warming, it does not follow that CO² is the primary driver of all historical warming events.

  30. “Dendrochronology is a precise science of using annual growth rings of trees to understand climate in the past.”
    Who do these so-called scientists think they are fooling when they write such drivel? When I read this, the author lost all credibility. Tree rings merely show good growth years and not-so-good growth years. The whys and wherefores causing the difference in growth from year to year, such as moisture, temperature and nutrient availability, has to be determined from other sources. All I can say is that PhD’s are now coming in cereal boxes!

  31. Is growth even consistent around the trunk? If not, growth patterns would depend on where you [took] the core.

    DaveE.

  32. “We did a lot of hiking and found a couple of sites of bristlecone pines, and one in particular that we honed in on,”

    Whoops! Hasn’t someone made that mistake before?

    In any case, I always thought the science was settled that tree rings were a proxy for temperature? Is this no longer true? Can we bury the (broken) Hockey Stick at last, then?

  33. Kevin MacDonald says:
    November 4, 2011 at 6:29 pm

    Anthony Watts says:

    “one wonders how such a thing could happens when CO2 was at “safe” levels”

    Only if “one” believes that CO­² is the driver for all climate change events, which nobody does. Pointless straw man comments like that do nothing to help the tone of the debate.

    Is it really a ‘straw man’ to say that alarmists are claiming there is a ‘safe’ level of CO2 above which were are heading for disaster? Methinks you are building your own ‘straw man’ and knocking it down when you say:

    Only if “one” believes that CO­² is the driver for all climate change events, which nobody does.

    You’re right, nobody does. What you failed to notice is that nobody claimed that anybody believed that either.

    Right back ‘atcha!

  34. Jay Davis;
    Who do these so-called scientists think they are fooling when they write such drivel?>>>

    Most of the people…. most of the time…

  35. “The tiny hole left in the tree’s trunk quickly heals as the tree continues to grow.”

    I feel sorry for the trees that made it over a thousand years, only to have holes drilled in them.
    They should put the core back where they found it after photo and measurements, sealing it up.
    Someday, they will lament over the loss of the bristlecone pines that were savaged by armies of grant-hungy climate golddiggers.

  36. I found this an interesting drought study right here in our Sierra Nevada back yard.

    Duration and severity of Medieval drought in the Lake Tahoe Basin
    J.A. Kleppea, D.S. Brothersb, G.M. Kentc, F. Biondid, S. Jensene, N.W. Driscollf

    Abstract

    Droughts in the western U.S. in the past 200 years are small compared to several megadroughts that occurred during Medieval times. We reconstruct duration and magnitude of extreme droughts in the northern Sierra Nevada from hydroclimatic conditions in Fallen Leaf Lake, California. Stands of submerged trees rooted in situ below the lake surface were imaged with sidescan sonar and radiocarbon analysis yields an age estimate of ∼1250 AD. Tree-ring records and submerged paleoshoreline geomorphology suggest a Medieval low-stand of Fallen Leaf Lake lasted more than 220 years. Over eighty more trees were found lying on the lake floor at various elevations above the paleoshoreline. Water-balance calculations suggest annual precipitation was less than 60% normal from late 10th century to early 13th century AD. Hence, the lake’s shoreline dropped 40–60 m below its modern elevation. Stands of pre-Medieval trees in this lake and in Lake Tahoe suggest the region experienced severe drought at least every 650–1150 years during the mid- and late-Holocene. These observations quantify paleo-precipitation and recurrence of prolonged drought in the northern Sierra Nevada.

    Steve McIntyre also has some interesting observations on these underwater tree rings at Climate Audit: http://climateaudit.org/2006/12/06/underwater-in-the-sierra-nevadas/

  37. This is the reason that Mann says there was no Medieval Warm Period

    Are you able to provide words to corroborate this, whether direct quotes from Michael Mann or from the body of words in any of his studies?

  38. Gary Pearse says,

    It would have been nice if they could have found some air bubbles in pine gum or some such to measure co2. Can we say from ice cores of these periods or other evidence that co2 was well below todays?

    Assuming local climate = global climate is a first order mistake of high magnitude.

    Records collated from various sources including ice cores indicate that global atmospheric CO2 levels were relatively steady for most of the holocene and started rising significantly towards the end of the 19th century.

  39. Kevin MacDonald says:

    “CO² is the primary driver of the current warming, it does not follow that CO² is the primary driver of all historical warming events.”

    So now it’s all different?? Clearly you have no understanding of the null hypothesis.

    • • •

    barry says:
    November 4, 2011 at 8:53 pm [ … ]

    barry me boy, Mann’s very own debunked MBH98 hokey stick chart attempted to erase the MWP and the LIA.

  40. Smokey, would you humour me with a no-dodge, straight-up, unadorned answer to a question?

    What would you say is the period for the Medieval Warm Period? Start and end dates, roughly?

    (If you answer this question, you will be the first skeptic I’ve ever seen to do so)

  41. I and the farmers will commend them for at least sensibly using tree ring thickness as a proxy for precipitation instead of using it as an indication for temperature. The archeological record has a long history of pointing to drought conditions in the West during the MWP.

    Anthony – keep up the humor. Most of us get it.

  42. “barry me boy, Mann’s very own debunked MBH98 hokey stick chart attempted to erase the MWP and the LIA.”

    I believe that the disappearance of the MWP and LIA was an unexpected consequence of the data handling that was, quite unfortunately, overlooked in the peer review of the Mann et al paper. My impression is that they have been trying to get the known history back without losing the hockey stick ever since.

    The hockey stick thing reminds one a bit of the Millerites who were pretty numerous, very loud, and — based on unequivocal biblical evidence — predicted the end of the world sometime in 1843 http://en.wikipedia.org/wiki/Millerism I mean, who are you and I to argue with the Book of Daniel as interpreted by Bible scientists?

  43. This research ties in well to tree ring records in the Sierra Nevada mountains of California that show the same thing – decades or even century long “mega droughts”.

    There’s a really cool story about how a scientist found full rooted pine trees in a lake near Lake Tahoe. The fact that the trees were deep in the water and full rooted indicated that they were growing when a flood occurred. Basically a extremely wet winter filled up the lake and killed the trees. Other evidence of trees in the Truckee River supported the research.

    There is also evidence of massive flooding in Southern California from atmospheric river events that easily dwarf any seen by man in the last 200 years.

  44. Mann tried to get rid of the MWP and LIA? That’s the biggest lie in the whole debate, and easily verified by going to the study behind the TAR ‘hockey stick’.

    MBH99:

    …Our reconstruction thus supports the notion of relatively warm hemispheric conditions earlier in the millennium, while cooling following the 14th century could be viewed as the initial onset of the Little Ice Age

    MBH98:

    The long-term trends in the reconstructed annual mean NH series (Fig. 5b) are quite similar to those of decadal Northern Hemisphere summer temperature reconstructions6, showing pronounced cold periods during the mid-seventeenth and nineteenth centuries…

    (Smokey, MBH98 only goes back as far as 1400AD. It doesn’t cover the MWP. MBH99 does. You keep mixing up the name of the studies. The so-called ‘iconic’ graph that appeared in the TAR is from MBH99, not 98 – check the links above)

  45. rbateman says:
    November 4, 2011 at 8:25 pm
    “The tiny hole left in the tree’s trunk quickly heals as the tree continues to grow.”

    I feel sorry for the trees that made it over a thousand years, only to have holes drilled in them.
    They should put the core back where they found it after photo and measurements, sealing it up.
    Someday, they will lament over the loss of the bristlecone pines that were savaged by armies of grant-hungy climate golddiggers.

    ==========================

    Extremely WELL SAID!

    Chris
    Norfolk, VA, USA

  46. OMG, my previous post was damn near unintelligible. That is the last time I try to do a quick post, reaching around two monitors to get to the keyboard while keeping an eye on test data :(

  47. Latitude says:
    November 4, 2011 at 6:00 pm

    So was it drought? cold temps? combination of both?………….we’ll never really know.
    Dendrochronology is a precise science……………….

    The droughts are the optimal interpretation. Colder temperatures would have resulted in shortened growing seasons but not other known effects. There are dendro samples from eastern Sierra Nevada collected from now-drowned pines that sprouted in ravine bottoms that are presently too wet for pines sprout or survive. Since at least some of the trees lived for two centuries or more, that means that the catchments for these ravines were subjected to very low precipitation. Lake Tahoe also ceased to feed the Truckee River for extended periods.

    California’s state government funded several studies in the mid-’70s in response to concerns over the drought taking place at the time. These droughts also appear to correlate with incursions of salt tolerant vegetation into the Sacramento-San Joaquin Delta. This indicates that river flows in the San Joaquin and Sacramento catchments were at times very low compared to modern flows.

  48. Yet another classic post on W.U.W.T.. Dont knock the Bristlecone Pines. They tell a valuable story relating to their patch over a long time.

    Most important story. Over 2,000 years the climate changed, was it hot, was it cold or arid. Matters not it CHANGED.

    Now plot the ring anomalies and start looking for comparisons. Dont forget drought can be cold. Driest place on earth, Antarctica.

    The Link to the sunken trees was terrific. Can they use their Dollars to put it all together and build a good climate record for the region.

  49. “What we can see from our record is that it was a period of basically 50 consecutive years of below-average growth,” said Routson. “And that’s within a much broader period that extends from around 124 A.D. to 210 A.D. – about a 100-year-long period of dry conditions.”

    According to Loehle’s non-tree-ring temperature reconstruction graph, the above period had sudden drop in temperatures. http://www.vukcevic.talktalk.net/LL.htm

  50. I enjoyed reading this up until the comment “there is reason to believe that human-driven climate change will increase the frequency of extreme droughts in the future”.

    It is sad that this kind of obviously stupid and unnecessary statement has become essential if you want to continue to receive grant funding.

    Mann cannot be too happy about this kind of article, as it is yet another example shredding the supposed logic of his infamous ‘hockey stick’ – in this case, previous warm periods and bristle cone pines reacting positively to extra moisture.

  51. barry says:

    “Mann tried to get rid of the MWP and LIA? That’s the biggest lie in the whole debate…”

    A lie?? Come on, barry, Mann and his acolytes are still trying to call the MWP the “MWA” [Medieval Warming Anomaly] or some such Orwellian term. Mann would like nothing better than to get rid of the MWP. Not that he’s getting any traction. When honest data is used, Mann’s chart becomes ho-hum.

    And IMHO tree rings aren’t very good proxies for past temperatures. They work better for past precipitation or drought conditions, and CO2 levels. Not that tree rings are anything like a proxy gold standard; they’re not. Tree growth is affected by many variables, and temperature by itself has only a very small effect.

    But the “Team” loves their tree rings. Briffa used one tree, YAD061, to make his hokey stick. Deleting that one tree erases the entire hockey stick shape. That is just pseudo-science.

    There is a direct connection between tree rings and grant money. It would be as if references to astrology generated grants; everyone would be putting natal charts into their peer reviewed papers. Tree rings may have their place, but the government should not be handing out our tax money based on them.

    Finally, to answer your question, the MWP ended somewhere between 1250 – 1300 AD. There is no universally accepted ending year, which is apparently what you want. Further, the MWP had cold episodes just like the LIA had warm years.

    In general, the peak of the MWP was as warm or warmer than the MWP [Modern Warming Period]. Therefore, what we’re seeing now can be completely explained by natural variability, with no necessity to add an extraneous variable like a minor trace gas to the explanation. William of Ockham would understand.

  52. Mike Davis says:
    November 4, 2011 at 5:09 pm

    They wasted money to find something that was already known. The times they are talking about are known transition periods from warm to cold. Maybe they should have studied historical climate records first!

    I rather like this example from John Daly’s paper on Tasmanian sea levels. Academics without common sense:

    On this issue, Hamon regrets to inform us – “We cannot apply a correction for atmospheric pressure in this case, as no Hobart data for for 1888 are available.” That lack of atmospheric pressure and wind data means that the Shortt observation would need a wide error bar after all…

    Although Hamon did not have those atmospheric pressure or wind figures, they were on public record. Once I concluded from the email discussion that pressure and wind uncertainty was the primary reason for the long 1888 error bar used by Pugh et al., it took me about half an hour at the public library to find the relevant data on pressure and wind in 1888.

    On 24th February 1888, the atmospheric pressure at Hobart was 29.96 inches, which converts to 1014.7 millibars. The wind was light south-easterly[10]. This information was contained in the `Shipping News’ of one of the local papers of the time, the Daily Telegraph.

    ‘Nuff said.

  53. “. . . has revealed a previously unknown multi-decade drought period in the second century A.D.”

    Having read the comments here, they haven’t done their homework. The drought was “previously unknown” to them. Talk about mental virginity.

    I was once (pre-internet) given a 3000-word essay on a subject about which only two textbooks (one rather short, the other only partially relevant) had ever been published. It took a while to find that out before I could start thinking about writing.

  54. There is one good thing about Mann’s hockeystick. When the historians are looking back, it can be used as documentation for the Teams bad science.

    Flat, and then rising? But where is the LIA and the MWP? Who made this up?
    They cannot dissappear the hockeystick.

    Very good, hey?

  55. how come a drought could bein southern US if US didn’t exist…
    it is high school geopgraphy stupid….

  56. Jer0me says:

    “Is it really a ‘straw man’ to say that alarmists are claiming there is a ‘safe’ level of CO2 above which were are heading for disaster?”

    No, but it is a straw man to argue that was the point I was making. Watts is implying that for AGW theory to be true carbon dioxide must be instrumental in in previous warming events (otherwise why mention it when linking to an article regarding a historical event?); this is simply not true.

  57. Tree rings on my farm do seem to record the droughts that have occurred in my lifetime. They don’t record the worst winters, for they were not growing during those winters. Individual trees also record ups and downs of their individual lives. However the extended New England drought of the mid 1960’s appears in all the older trees. I conclude tree rings do better at recording rain than temperature.

    RE: Ulric Lyons says: November 4, 2011 at 6:08 pm
    That link to records from Syria is very interesting. It gives one a clear idea of how devastating drought and cold waves can be to small villages of farmers. Also how a change in weather patterns can help one part of the world while ruining another. Usually people over-simplify, regarding the Middle East, and blame everything on overgrazing. The booms that resulted from irrigation were interesting to read about.

    One interesting article I read back around 1986, in a small newspaper in Gallup, New Mexico, described an archeologist looking up from some pottery shard he was whisk-brooming, and seeing a reporter actually be interested in his obscure work (at that time.) He explained to the reporter he was bothered by facts not fitting his theory, and how he was having his arm twisted by the facts, and being forced to come up with a new theory.

    As I recall the site he was investigating had not been abandoned during the period of extended drought, but just after the rains returned. It made no sense that the ancient ones had survived the hard times, but bailed when the good times returned.

    What the archeologist was surmising was that the irrigation systems had actually worked well, and been improved upon, during the extended drought, but that, when the rains returned, they were not gentle winter rains, but rather summer “gully washers.” The carefully-built irrigation systems were not merely knocked down, but also left high and dry, for the streambeds were eroded and lowered to a degree where water no longer flowing into the inlets, and the canals were rendered useless.

    The irony of the theory was not lost on me: After years of praying for rain, it was rain and not drought that ruined things.

    I’d like to find that old article. It would be nice to read something where neither the scientist nor the reporter felt any need to link their discussion to Global Warming. Those were the days!

  58. Barry:

    “This is the reason that Mann says there was no Medieval Warm Period”

    Are you able to provide words to corroborate this, whether direct quotes from Michael Mann or from the body of words in any of his studies?

    But of course. I’m glad you asked.

    This is from Mann’s embarrassingly hagiographic interview conducted by the wretched David Appell for Scientific American in 2005:

    For instance, skeptics often cite the Little Ice Age and Medieval Warming Period as pieces of evidence not reflected in the hockey stick, yet these extremes are examples of regional, not global, phenomena.

    I covered this article at the time. You can find it if you Google “site:climateaudit.org hagiography”

    Oh, and you’re welcome.

    (what are the chances that Barry will acknowledge his error? I’m not holding my breath)

  59. Further down into Mexico and Yucatan, the first Mayan civilization collapsed entirely, due due long term drought in the 1./2/ Cty., Little is left of it…. this is what long decadal droughts produce….. Colorado is located at the periphery of this antique civilization…..
    …… What was the CO2-output at this time? Anybody knows? At which CO2-level will we collaps again?…..
    JS


  60. Kevin MacDonald says:
    November 4, 2011 at 7:29 pm
    Smokey says:

    “WHAT??
    CO2 as the primary cause of runaway global warming, climate catastrophe and climate disruption is the central claim of the red faced, spittle-flecked alarmist crowd. Without “carbon” to demonize, what would they have? DDT? Methane? Ozone? Pf-f-f-ft.”

    CO² is the primary driver of the current warming, it does not follow that CO² is the primary driver of all historical warming events.

    Kevin – your reasoning is lacking. The entire alarmist case is based on two provisos:

    1. The current climate is ‘unprecedented’
    2. The current level of CO2 is ‘unprecedented’

    Therefore the reasoning is that the CO2 level caused the climatic effect. ‘as there is nothing else that could have caused it’.

    What this study has done is show that proviso 1 is false. The current climate is not unprecedented.
    If the climate conditions now have happened before when the ‘unprecedented’ levels of CO2 were not present – then the argument ‘as there is nothing else that could have caused it’. fails as obviously something else caused the previous similar climate conditions when CO2 was not at its current ‘unprecedented’ levels.

    This paper has just disproved the AGW hypothesis

  61. All that happens is that the permanent climate zones change in intensity and latitudinal position cyclically over time as a result of an interaction between variations in the oceans and the sun.

    There is no climate change for the globe as a whole in terms of any significant change in the global equilibrium temperature (or energy content ). The so called faint sun paradox is the evidence for that.

    Those changes in the permanent climate zones are the global thermostat in action because such changes reflect adjustments in the rate of energy flow through the system. Such adjustments always serve to negate any factors that seek to alter the energy content of the entire system.

    The coming and going of south west US drought conditions is just one regional manifestation of such changes as is the coming and going of drought conditions in the Sahel.

    If we can get the timing and location of past regional climate changes defined with adequate precision (apparently not yet) I am sure we will find that regional changes in the climate zones occur around the world in each hemisphere approximately in unison as the global energy budget is adjusted to maintain system stability.

    All that the surface record ever tells us is the regional response (where the sensors are – mostly in populated mid latitudes in the northern hemisphere) to a mix of shifting climate zones overhead and UHI effects.

    Only the satellite record has any value in global terms and that will always be much more stable than surface temperature records because satellites measure variations in the energy budget for the globe as a whole and so are unaffected by the larger regional swings which occur as the climate zones shift about or UHI effects develop around surface sensors.

    Forget about global climate change. Everything we observe boils down to shifting climate zones which adjust the rate of energy flow through the system.

    Offers of research funds welcome :)

  62. And here was me, believing than Dendrochronolgy, was a method of dating wood & wooden artifacts by examining their ring width sequencies.

  63. Just finished reading “Cahokia Mounds: America’s First City” by William Iseminger. From p. 150:

    “There is evidence of climate change occurring at different times in the Midwest that may have affected the growth and development of Cahokia and also contributed to its demise. A period of more favorable climate began about the time that Cahokia developed as a major community and continued to about AD 1135. Around that time, a period of drought occurred that lasted for about 35 years or more, adding an element of stress to an already fragile economy and political system.”

    The medieval drought may have stretched as far as the midwest. I can’t imagine what a 35 year drought would do to the corn belt today.

  64. Did anyone notice that both of these droughts came at the end of a warming period, just before it went cold?

  65. Smokey,

    Finally, to answer your question, the MWP ended somewhere between 1250 – 1300 AD.

    Good. A first! Now, you realize that MBH98 starts in 1400. It has nothing to do with the medieval warm period. The graph you are always linking to is from MBH99, which does cover the MWP time frame.

  66. “Darker wood, referred to as latewood because it develops in the latter part of the year at the end of the growing season, forms a usually distinct boundary between one ring and the next. The latewood is darker because growth at the end of the growing season has slowed and the cells are more compact.”

    Not exactly. Hopefully I won’t come across as the “pedantic” forester on this list, but latewood is darker mostly because the cell walls are much thicker than in so-called earlywood. Cell wall thickness is very closely correlated to specific gravity, so latewood is much denser and stronger than is earlywood.

    In Douglas-fir growing in areas of mild climate and intermittent late summer rains, latewood proportions can be significant, producing fairly wide bands.

  67. Increasing climate temperatures = increasing civilization
    Decreasing climate temperatures = decreasing civilization

    Is there anything else, we REALLY need to know? GK

  68. One other comment about narrow growth rings: we also know that severe defoliating insect outbreaks that last for a period of years also correlate very well with reduced growth. In the case of bristlecone pines in the SW, I would lean more toward the drought thesis, but in other areas of the globe, we frequently see very tight growth rings for periods of 10 years or more that coincide with known defoliating insect outbreaks. In some years, trees may appear to have produced almost no radial growth, and thus one growth ring may actually represent 2 years in time.

    As stands grow up and before natural thinning occurs, overstocked stands also show very much reduced radial growth for a number of years.

  69. “Increasing climate temperatures = increasing civilization
    Decreasing climate temperatures = decreasing civilization”

    You need to consider rainfall too. Cold and drought are the main problems but a problem too is that a warm wet environment is not conducive to civilisation either because food and water are abundant so the people don’t need to work too hard whilst at the same time natural predators, parasites and diseases are rife to keep the death rate high.

    The best inducement to civilisation is a regularly varying mix of not too extreme weather types such as in the mid latitudes where changing seasons force people to be adaptable.

  70. “… there is reason to believe that human-driven climate change will increase the frequency of extreme droughts in the future, said Routson”

    Why don’t they just put a WUWT style ad:
    “Donations accepted: fling funds”

    At least it is above board and straight forward.

  71. Stephen Wilde says:
    November 5, 2011 at 10:49 am

    “Increasing climate temperatures = increasing civilization
    Decreasing climate temperatures = decreasing civilization”

    You need to consider rainfall too. Cold and drought are the main problems but a problem too is that a warm wet environment is not conducive to civilisation either because food and water are abundant so the people don’t need to work too hard whilst at the same time natural predators, parasites and diseases are rife to keep the death rate high.

    I was speaking from a historical context. History requires no justification. I was not referring to localized climate, but global instead. Globally a warmer, wetter, world is better for civilization (especially if it is CO2 enhanced). Carbon usage also varies as civilization ebbs and waxes. We don’t have to understand it – to make the observation historically. GK

  72. That there were droughts in the past is beyond dispute, but it is not an excuse for us to be cavalier now. The natural conditions which contributed to droughts in the past, are now exacerbated by man-made forcing and it is likely that these unfortunate events will be more frequent and of a greater duration. Although I’m sure you will dispute the relationship between CO2 in the atmosphere and weather events, even climate change, those of us who do accept this connection are deeply concerned about our collective capacity to cope with challenging climate changes and extreme weather events. (Texas -drought, widfires -everywhere; massive flooding – everywhere; uncharacteristic weather events -NE states and everywhere; heat waves – europe and southern states etc)

    The US Department of Energy has recently released data which shows that global warming gases released into the atmosphere “made an unprecedented jump” in 2010, with a 500 million metric ton increase in a single year. This represents a 6% rise between 2009 and 2010. This is not good news.

  73. Hugh Pepper says:

    “The natural conditions which contributed to droughts in the past, are now exacerbated by man-made forcing and it is likely that these unfortunate events will be more frequent and of a greater duration.”

    “Likely”? Based on what? Hugh, you may believe that, but like astrology and Scientology, there is zero evidence to support your belief. OTOH, there is ample evidence that the added CO2 is beneficial to the biosphere. Think of it as harmless airborne fertilizer, you’ll sleep better.

  74. Hugh Pepper – Droughts, floods, hurricanes, tornadoes, earthquakes, volcanic eruptions, and other natural phenomena have occured in the past, are occuring now, and will occur in the future. Man has absolutely no control over them. Man can only try to mitigate the damage caused by them through intelligent siting of buildings and cities, better engineered structures and so on. Therefore if you tell me we should not build along coastlines that are frequently hit by hurricanes, I’ll agree with you. If you tell me we shouldn’t build in flood plains, I’ll agree with you. But don’t tell me we have to lower our standard of living, or deny others the chance to improve theirs, because of a definitely unproven (and as far as I’m concerned false) hypothesis that an odorless, colorless trace gas required by all green plants to produce the oxygen and food that sustains life on this earth will cause the planet to overheat!

  75. Hugh Pepper says:
    November 5, 2011 at 12:03 pm

    The US Department of Energy has recently released data which shows that global warming gases released into the atmosphere “made an unprecedented jump” in 2010, with a 500 million metric ton increase in a single year. This represents a 6% rise between 2009 and 2010. This is not good news.

    Hmmm, this happened while a “green president” was in power. This happened while thousands of wind farms and solar farms came into service. This happened when everyone replaced their incandescent(s) to flourescent(s). This happened while recycling is at maximum and bio-fuel production is exploding. This happened despite all the climate conferences and despite A.Gore.

    You do understand the repercussions, of performing the same actions, over and over, expecting a different result. The question arises – Do YOU finally accept the result?? GK

  76. Just thought of something – if those trees were recently cored, then we now have tree rings NEWER than the old Greybill proxies (which IIRC, was back in 1993).

    This means that we can now see if RECENT rings accurately follow the last 17 years of temperature rise.

    Kinda like a two-for-one data source. They extended the past, AND updates the proxies.

    So it’s probable that their work not only showed previous droughts not caused by CO2, but could show that the trees aren’t following current instrumental temperature records.

    Who’s our resident Dendrochronologist?

  77. Hugh Pepper says:
    November 5, 2011 at 12:03 pm

    Assertion is easy. Verification, however, requires proof. You assert that “this is not good news”. Is it bad news? If so, why?

  78. John A @ <a href=http://wattsupwiththat.com/2011/11/04/roman-period-megadrought-found-in-the-usa-southwest/#comment-788489

    That is the journalist’s copy, not the words of Michael Mann. Remember I asked you,

    Are you able to provide words to corroborate this, whether direct quotes from Michael Mann or from the body of words in any of his studies?

    Even so, I will deal with what you have cited. I hope you return the courtesy.

    Parsing the journo’s take, we find


    the Little Ice Age and Medieval Warming Period…. are examples of regional, not global, phenomena.

    So the MWP and LIA exist after all?

    It’s not that Mann denies anomalous warmth and coldness in the MWP and LIA, he just doesn’t agree with the character of those periods and touted by skeptics (ie, MWP global and warmer than recent)

    Your quote is from 2005. Mann has consistently said (from 1999 to present) that there was anomalous warmth in the medieval period and qualified that it was mainly restricted to the Northern Hemisphere and unlikely to have been as warm as the last few decades. He has also consistently referenced the LIA in his work, and discussed the spatial and temporal parameters of that period, too (as well as potential drivers for both) The lie about this is given out by skeptics who are intemperate, and can’t or won’t speak to the truth of the matter.

    I’ve already cited Mann directly from his two most controversial papers, MBH98 and 99 identifying and qualifying the MWP and LIA.

    Will you acknowledge that?

    From a more recent study, Mann et al 2008.

    The reconstructed amplitude of change over past centuries is greater than hitherto reported, with somewhat greater Medieval warmth in the Northern Hemisphere, albeit still not reaching recent levels…

    It is intriguing to note that the removal of tree-ring data from the proxy dataset yields less, rather than greater, peak cooling during the 16th–19th centuries for both CPS and EIV methods (see Figs. S5a and S6b, respectively), contradicting the claim (33) that tree-ring data are prone to yielding a warm-biased “Little Ice Age” relative to reconstructions using other high-resolution climate proxy indicators. …

    Peak Medieval warmth (from roughly A.D. 950-1100) is more pronounced in the EIV reconstructions (particularly for the land-only reconstruction) than in the CPS reconstructions (Fig. 3). The EIV land-only reconstruction, in fact, indicates markedly more sustained periods of warmer NH land temperatures from A.D. 700 to the mid-fifteenth century than previous published reconstructions. Peak multidecadal warmth centered at A.D. 960 (representing average conditions over A.D. 940–980) in this case corresponds approximately to 1980 levels (representing average conditions over 1960–2000)….

    We could arguably take these two reconstructions as end members that bracket the possible range for peak NH mean Medieval warmth, lying somewhere between 0.4°C colder and and 0.4°C warmer than the modern reference period (1961–1990) mean, but still exceeded by the most recent decadal warming.

    And so on.

    The abstract of a 2009 paper, “Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly” goes;

    Global temperatures are known to have varied over the past 1500 years, but the spatial patterns have remained poorly defined. We used a global climate proxy network to reconstruct surface temperature patterns over this interval. The Medieval period is found to display warmth that matches or exceeds that of the past decade in some regions, but which falls well below recent levels globally. This period is marked by a tendency for La Niña–like conditions in the tropical Pacific. The coldest temperatures of the Little Ice Age are observed over the interval 1400 to 1700 C.E., with greatest cooling over the extratropical Northern Hemisphere continents. The patterns of temperature change imply dynamical responses of climate to natural radiative forcing changes involving El Niño and the North Atlantic Oscillation–Arctic Oscillation.

    Michael Mann, his colleagues and the paleoclimate community acknowledge that the medieval period was warm, and that there was a cold period, popularly known as the Little Ice Age. Mann has not tried to ‘get rid’ of these phenomena. On the contrary, he discusses their breadth and magnitude, to say the least.

    Die-hard skeptics, it seems, have decided that MWP = warmer than today, and any conclusion that differs from this is someone trying to ‘get rid of’ the MWP. But that’s not skepticism, that’s just jingoism.

    John, will you acknowledge that Mann describes a medieval warm period and a cool period known as the Little Ice Age in his work?

    • Barry,
      you disqualify yourself with being a stout defender of Mann and his hockey stick……
      with all his nonsense….

      Please, there is a lot of new work, which show, that (1) the LIA was deeper in temps as the little bit, which Mann concedes, as well as (2) temps in the MWP were much higher that Mann concedes (which means the “stick” is not straight as he insist ….only “a tiny bit curved”)
      (3) In still temporary absence of studies in the Southern Hemisphaere (which will come up in time), he just invents that the deeper LIA and higher MWP occured on the North. Hem.,
      (4) please see the latest graph of global land temps of BEST from 1800-2000 (and as you
      know, the 1800-1850 temps are on land higher than in a. the South.Hem. and b. over the ocean, total of the three still depper still….. how do you integrate these BEST values 1800-50 into the hockey stick……?
      Please put Mann et al to their rest, they have disqualified themselves in climate science…..
      Check and critize my book, please find mistakes….. that would be of service to science, forget Mann and his crowd, they will be taken out of science anyway in a couple of years….

  79. @Caleb says:
    November 5, 2011 at 4:34 am
    “RE: Ulric Lyons says: November 4, 2011 at 6:08 pm
    That link to records from Syria is very interesting. It gives one a clear idea of how devastating drought and cold waves can be to small villages of farmers. Also how a change in weather patterns can help one part of the world while ruining another.”

    But then as those cold winters are evident on all continents across the hemisphere, it does tend to imply external forcing.

  80. @ Kevin MacDonald: No one is arguing that correlation equals causation, warming is ascribed to CO² because we know it’s physical properties, so this is yet another straw man.
    Your implied straw man is that we skeptics don’t know the physical properties of C02, i.e. that it is a greenhouse gas. We know why warming is ascribed to C02, and it has little to do with science or reality. Your argument is a big FAIL.

  81. Barry:

    John, will you acknowledge that Mann describes a medieval warm period and a cool period known as the Little Ice Age in his work?

    No Barry I will not.

    Mann made clear that he regards the previously well-accepted paradigm of global medieval warmth as false because his fabulous statistical exercise told him so. The quote was not something that David Appell simply made up and put in Mann’s mouth – it was clearly something that Mann was communicating through his works from 1999 onwards.

    I find your arguments to be “sophisticated” because they are sophistry, designed to make Mann look as though he was arguing for a Medieval Warm Period and Little Ice Age as global phenomena when he clearly wasn’t.

    In fact Mann spent a great deal of time and effort claiming that the Modern Warming was unprecendented in the last 600, 1000 and even 2000 years. He even described those events as being localised to the North Atlantic basin.

    He only changed his tune relatively recently because a) his reconstructions of past temperatures were found to be riddled with errors and veridically false statements and b) despite his and the Hockey Team’s best efforts to block, the evidence for Medieval Warmth and Little Ice Age cold continued to be described in all parts of the globe.

    Are you going to continue to claim Mann was arguing for the global reach of these phenomena when he clearly wasn’t or will you do the decent thing and apologise?

  82. Bruce Cobb says:

    “Your implied straw man is that we skeptics don’t know the physical properties of C02, i.e. that it is a greenhouse gas. We know why warming is ascribed to C02, and it has little to do with science or reality. Your argument is a big FAIL.”

    I was addressing a specific poster and my comments, my comments were directed only at him and implied nothing about the state of knowledge amongst the wider “skeptic” community. Ian W’s incorrect assertion that the entire case for AGW theory hinges solely on the correlation between temperatures and CO² requires, by definition, that there is no physical mechanism that backs the theory up. Given those circumstances, it is fair to infer that Ian W is unaware of the physical properties of CO².

  83. Kevin MacDonald says:

    “No one is arguing that the current climate is unprecedented…”

    …which means the null hypothesis remains unfalsified. Therefore, the alternate CO2=CAGW conjecture is on the rocks and sinking fast.

  84. RE: Main Article
    “Dendrochronology is a precise science of using annual growth rings of trees to understand climate in the past.”

    Of course, “Dendrochronology” is a precise science for measuring relative *time* by tree-ring correlation. It might be better to say something like ‘Dendro-climatology’ is an imprecise science using the unique properties of annual tree growth-rings to estimate possible climatic conditions in the past.

  85. Are you going to continue to claim Mann was arguing for the global reach of these phenomena when he clearly wasn’t or will you do the decent thing and apologise?

    I cannot ‘continue’ to claim Mann was arguing the MWP was global, because I never did in the first place. As I said, Mann argues that it is a regional phenomenon. The result is warmer global temperatures, but not as warm as today.

    Mann did not try to ‘get rid’ of the MWP. It is there in his reconstructions along with the LIA. He just doesn’t think the MWP was globally as warm as today. Neither you nor anyone else commenting here is qualified to judge the truth of the matter, and he is entitled to his opinion. It is not a controversial opinion in the halls of paleoclimate, where different groups using different methods and data find similarly. OTOH, a small number of papers suggest the MWP was global in extent/warmer than today.

    It’s worth getting familiar with the literature on this. these links are a good pace to start.

    http://agwobserver.wordpress.com/2009/09/08/papers-on-the-mwp-as-global-event/

    http://agwobserver.wordpress.com/2009/11/17/papers-on-reconstructions-of-modern-temperatures/

    http://agwobserver.wordpress.com/2010/02/24/papers-on-temperature-reconstructions-from-boreholes/

    http://agwobserver.wordpress.com/2010/02/28/underground-temperatures-as-indicators-of-surface-temperatures-part-1/

    http://agwobserver.wordpress.com/2010/03/03/underground-temperatures-as-indicators-of-surface-temperatures-part-2/

    Having read many (not all) of these papers I know that Mann’s conclusions are common across paleoclimate studies. Because his work is not out of step with the wider body of the science, I conclude that the relentless attack on him is politically motivated.

    A couple of suggestions came to me upthread to quit defending Mann. And if I did? If we threw out all of Mann’s work on paleoclimate? The preponderance of scientific opinion would remain that there was an MWP and an LIA and recent temps are very likely warmer than a thousand years ago. I don’t need Mann, but the skeptics certainly do. It helps the cause to have a bogeyman.

    But all I wanted to do was point out that there is an MWP and an LIA in Mann’s work. He hasn’t tried to get rid of them, he just describes them differently to skeptics, who – as an article of faith, not reason – believe that the MWP was definitely warmer than today. In order to hold that opinion, they must dismiss 90% of papers on global or hemispheric paleoclimate, and instead focus on highly selected papers, usually about a small region or locale or, more often, non peer-reviewed ‘blog’ science.

  86. barry,

    Give up on the silly claim that the MWP was regional. Here’s an interactive chart clearly showing the MWP’s global reach in both hemispheres. And the MWP was exceeded by several even warmer periods – when CO2 remained very low.

    Mann is just backing and filling, trying to obfuscate his earlier claims that tried to erase the MWP and the LIA. Michael Mann is a climate charlatan who collects plenty of taxpayer loot for his alarmism. But what do you get out of being his apologist?

  87. If you check out the chart with care, Smokey, you will discover that the MWP happens at different times in different places, by up to 700 years apart. This accords with Mann’s take of a temporally/spatially incoherent MWP, so it’s not a good chart to use as a rebuttal. Also, some of the indicators on that chart are to do with rainfalland other climate indicators, not temperature.

    I have to credit you with substantiating my claim that skeptics don’t refer to the peer-reviewed literature, but instead rely on blog science. Thanks, me hearty.

    To substantiate my comments above, simply roll over all the graphs and note where the MWP lies. For instance, at Lake Teletksoye, the peak of the MWP is around 1400, while temps are quite low around 1200. OTOH, sea surface temperatures in Iceland peak at 750AD, while the temperature in 1400 is lower than recent. And in Southern Alaska MWP peaks at 1000 – 1100, while 750 and 1400 are cool periods. These 3 reconstructions contradict each other.

    There’s plenty more like that from your chart corroborating the view that the MWP was not spatially or temporally coherent. I’ve pointed this out to you on a previous occasion when you brought this chart up, but it seems to have made no impression. At the very least, you are consistent. :-)

  88. Smokey says:

    “…which means the null hypothesis remains unfalsified. Therefore, the alternate CO2=CAGW conjecture is on the rocks and sinking fast.”

    The null hypothesis contains no physical mechanism that can explain recent warming, it is on far shakier ground than AGW theory.

  89. Kevin MacDonald says:
    November 6, 2011 at 7:36 pm

    Smokey says:

    “…which means the null hypothesis remains unfalsified. Therefore, the alternate CO2=CAGW conjecture is on the rocks and sinking fast.”

    The null hypothesis contains no physical mechanism that can explain recent warming, it is on far shakier ground than AGW theory.

    Klewless. The null does not require a “mechanism”. It simply states that other unknown mechanisms are likely responsible for the warming. This has not only not been rejected, it is far and away more likely to be true than the AGW WAG.

  90. “If it’s a wet year, they grow a wide ring, and if it’s a dry year, they grow a narrow ring,” said Routson.

    So now they are rain gauges. Seems like only yesterday they were thermometers.

  91. Barry:

    Mann did not try to ‘get rid’ of the MWP. It is there in his reconstructions along with the LIA. He just doesn’t think the MWP was globally as warm as today. Neither you nor anyone else commenting here is qualified to judge the truth of the matter, and he is entitled to his opinion.

    Oh please Barry you protest too much. Mann clearly has a right to his own opinion but he has not right to his facts. You make references to attacks on Mann as politically motivated because you deny the clear demonstration of evidence from multiple sources that those “facts” were confabulated.

    There is clear evidence that Medieval Times had a sustained period of longer summers and milder, shorter winters than today, evidence such as tree lines being more poleward and higher altitudinally than they are today. It would be surprising given the differing nature of paleoclimatic proxies that we can say exactly when this period began and when it ended.

    I cannot say for certain that the Medieval Period was universally warmer than it is today, but I can point to evidence from all over the world that the current warm period is far from unprecedented.

    Mann’s “opinion” was offered as the “smoking gun of AGW” and the clear highlight of the IPCC TAR. It turned out that that “opinion” was confabulated and that Mann knew well before Steve McIntyre got involved that one proxy dominated his reconstruction to such an extent that without it, the distinctive shape disappeared, and his public statements to the effect that his results were robust to the removal of dendroclimatic indicators, as well as his claim to not have calculated the R2 metric on his results were knowingly false when he made them.

    These statements made by me are not politically inspired. They are based on facts which are beyond dispute.

  92. I’m glad you’re not interested in the political angle (me neither), so let’s stick to the science. If you throw out every reconstruction that Mann was lead or co-author on, then still the weight of evidence from multiple millennial reconstructions supports the notion that the MWP was not globally synchronous, and that recent decades were probably warmer.than equivalent periods in the last couple of millennia. And that ‘fact’ is really not that important in the scheme of things. But some carry on as if the whole theory of AGW rests on how hot the MWP was.

    If we’re going to stick with the science, then dropping Mann from the picture changes nothing. There’s not much daylight between MBH98 and 99 and the convergence of evidence in the literature. That is a fact, and it is about the science, not about who said what when, what it meant, who was right or wrong, or what graph was in the IPCC 10 years ago.

    Mann is a bogeyman, where nitpicking 12 year-old studies that have long been superseded is elevated into a witch hunt of proportions only of interest to those with an axe to grind. I mean, suppose the whole world agrees MBH99 is flawed, Mann is a liar, and none of his work can be trusted. Does that mean we can focus on what the rest of the science says? If so, what do you imagine you will discover? Have you even tried reading the literature broadly (as opposed to, for example, trawling agenda-laden websites for their fave picks) to get a feel for what the general opinion is on millennial climate anomalies?

    This brouhahaha over Mann seems to me like the biggest waste of passion ever. The best you can hope for is the dismantling of Mann’s reputation and career. What a shoddy objective. The science will remain the science, and the people trying to bring Mann down are completely disinterested in it. Like you, they won’t follow my links to lists of papers on millennial reconstructions because understanding the subject is not the point. Smashing Mann IS the point. And for you, being skeptical about what Steven McIntyre says isn’t even an option. It’s a matter of faith.

    Me, I don’t know if Mann was deliberately deceptive. Seems unlikely. But I do know that it doesn’t matter a damn except in the fevered world of rabid loathing for the notion of AGW. What I do know is that Mann did not get rid of the MWP or LIA, and that Smokey’s chart completely undermines the point he’s trying to make while corroborating Mann’s (and the majority in paleoclimate) view of a MWP that was not synchronous. I can correct the obvious stuff. If you think you’re all over the nuances, more strength to you. I’ve read the reports, too and Steve Mc, and I still don’t think I’m qualified to judge. Your assertions do no more to persuade than the denser material I’ve read.

    I’m not defending Mann. Screw him. I’m just trying to set the record straight where it’s obviously wrong.

  93. Brian H says:

    “Klewless. The null does not require a “mechanism”. It simply states that other unknown mechanisms are likely responsible for the warming. This has not only not been rejected, it is far and away more likely to be true than the AGW WAG.”

    Broadly speaking, any null hypothesis is; “what we know is true.”, by definition it cannot contain unknowns because, if it could, it would be untestable, unfalsifiable, and you would be, in effect, arguing; “we can’t know anything unless we know everything.” As far as climate change is concerned, what we know about natural variability isn’t true, because it does not explain the recent warming, therefore an alternate hypothesis is required. Personally, I subscribe to AGW, but if you have a better theory, please enlighten me.

  94. Kevin MacDonald still has no understanding of the null hypothesis. Here is the definition: The Null Hypothesis is the statistical hypothesis that states that there are no differences between observed and expected data.

    I doubt that Mr MacDonald even understands what the definition is telling him. The climate null hypothesis is limited to historical evidence. If one or more of the parameters of the Holocene were exceeded, then the null hypothesis would be falsified. But that has not happened. As Dr Roy Spencer says, “No one has falsified the hypothesis that the observed temperature changes are a consequence of natural variability.”

    The null hypothesis does not ‘explain’ anything. Its purpose is to show that there has been no change exceeding prior natural climate parameters, despite the ≈40% rise in [harmless, beneficial] CO2. If temperatures, or trends, or duration, etc. of the planet during the Holocene prior to the industrial revolution are exceeded, then the null is falsified. If not, then the alternative CO2=CAGW conjecture fails. And that is exactly the situation: CO2=CAGW fails because nothing unprecedented is occurring. The planet’s climate is well within the parameters of natural variability.

    [BTW, AGW is not a “theory”; it is a conjecture because it is not testable, at least not currently. If AGW becomes testable and falsifiable per the scientific method, it will still not be a theory. But it will be elevated from conjecture to the status of hypothesis.]

  95. Kevin MacDonald says:
    November 7, 2011 at 5:45 pm

    Brian H says:

    “Klewless.”

    . Personally, I subscribe to AGW, but if you have a better theory, please enlighten me.

    What you said, Smokey.
    In addition, what we “know” is that climate varied widely on its own long before AGW’s putative influence. That’s all the null needs to observe.
    Trooly Klewless.

  96. Barry:

    One of the most irritating things in my universe is the “concern troll”, someone who claims to be on the side of truth, but when it comes down to it simply spends an awful lot of time with ever longer posts of fatuous irrationality designed to bore opponents into submission.

    So here goes your arguments:

    I’m glad you’re not interested in the political angle (me neither), so let’s stick to the science.

    Start with a statement in which we can all agree, and then pour in rhetorical acid:

    If you throw out every reconstruction that Mann was lead or co-author on, then still the weight of evidence from multiple millennial reconstructions supports the notion that the MWP was not globally synchronous, and that recent decades were probably warmer.than equivalent periods in the last couple of millennia. And that ‘fact’ is really not that important in the scheme of things. But some carry on as if the whole theory of AGW rests on how hot the MWP was.

    This is called the “begging the non sequitur wrapped in the red herring” argument. If I threw out every reconstruction that Mann was lead or co-author on, I’d still be left with a lot of reconstructions that used proxies of dubious relationship with temperature, a lot of which would use Mann’s PC1 as a proxy and even more that would use Mann’s own statistical techniques.

    And they can produce whatever the “modeler” wants. Which means they can produce something entirely meaningless and it flies through the peer review process quicker than you can say “Nobel Peace Prize”

    Whether or not the MWP was globally synchronous depends crucially on whether the proxies are measuring something that equates with “mean temperature” or “length of summer season” or “precipitation”.

    Here’s the “begging the question”: science is not decided by weight of numbers, but by careful controlled experiment that reduces error and produces unimpeachable results. And that means that one well-done repeatable experiment trumps completely a million badly-done ones waved through the laughably fraud-prone peer review process.

    If we’re going to stick with the science, then dropping Mann from the picture changes nothing. There’s not much daylight between MBH98 and 99 and the convergence of evidence in the literature. That is a fact, and it is about the science, not about who said what when, what it meant, who was right or wrong, or what graph was in the IPCC 10 years ago.

    So what is your argument? That the question has been decided? It ain’t so, bro. The convergence of evidence in the literature is an artifact of the collapse of the peer review system and the publication bias of sensational claim over cleverly argued rebuttal. The Climategate correspondance revealed it in clear detail – that a small coterie of activists can subvert an entire science and censor and bully all criticism into the bargain.

    Mann is a bogeyman, where nitpicking 12 year-old studies that have long been superseded is elevated into a witch hunt of proportions only of interest to those with an axe to grind. I mean, suppose the whole world agrees MBH99 is flawed, Mann is a liar, and none of his work can be trusted. Does that mean we can focus on what the rest of the science says? If so, what do you imagine you will discover?

    That’s right. Nitpicking to point out that the “Smoking Gun of Global Warming” was a shocking fake and the massive amounts of money corralled to alter the world’s economy on the basis of this evidence were and are thoroughly wasted. It’s a “witchhunt” to point this out.

    What does the rest of the science say? We don’t know because of the gaming of the scientific publication and review system by the self-styled “Hockey Team”

    See, Barry, in your purblind world of charge and counter-charge, facts are the first casualty. Its really about politics and prejudices and social contexts. Facts be damned.

    I’ve seen really intelligent, clever people whose professional lives have been ruined by the Smashmouth politics of Left and Right that have arisen over issues as delicate as whether the Earth was really warmer or cooler 1000 years ago, but more importantly, whether the present warming period is “unprecedented”.

    But what does that matter? Anyone who sides with a “consensus” is correct and anyone who examines that “consensus” is a Denier, a pursuer of a “witchhunt” and a co-conspiritor with unnamed people paid by fossil fuel companies to spread lies. This has become the Grand Narrative of our Times.

    It matters that Mann is investigated, because history itself has been poisoned and perverted in the cause of “Yet Another Noble Cause”. It matters because history matters, because facts matter, because any decision built on lies will cause needless hardship for millions.

    Have you even tried reading the literature broadly (as opposed to, for example, trawling agenda-laden websites for their fave picks) to get a feel for what the general opinion is on millennial climate anomalies?

    General opinions are like arseholes. Everyone has one. What I want is science done with the minimum of publicity-seeking and the maximum of attention to proper methodology and meaningful data.

    Everyone has an agenda. You have one. I have one. Anthony has one. But the question of relative warmth 1000 years ago is not a litmus test of political views although there are quite few people who think it is.

    Have I read the literature? Yes. Do I think that scientific facts should be decided by popularity? Absolutely not. Are all scientific papers equal? Hardly. Are scientific journals giving equal weight to criticism? Clearly not.

    This brouhahaha over Mann seems to me like the biggest waste of passion ever. The best you can hope for is the dismantling of Mann’s reputation and career. What a shoddy objective. The science will remain the science, and the people trying to bring Mann down are completely disinterested in it. Like you, they won’t follow my links to lists of papers on millennial reconstructions because understanding the subject is not the point. Smashing Mann IS the point. And for you, being skeptical about what Steven McIntyre says isn’t even an option. It’s a matter of faith.

    Nonsense. That’s the same rubbishy argument produced by David Appell – that “bring down Mann and the whole AGW edifice will come crashing down”.

    The science will NOT remain the science, because science is always provisional and subject to audit, change and review. The idea that “the Science will remain the Science” is a clearly religious statement akin to Dogma.

    I don’t have to believe or disbelieve Steve McIntyre. I’ve met him face-to-face three times and he has never asked me to believe in what he says. Steve deals in facts and statistical theory that underpin what science is all about – testable and repeatable models, data and experiments. There is a reason why Steve McIntyre is so feared – because he’s more clear-minded about what science is about than the Hockey Team will ever be.

    Would it make a difference if Mann were found out as a charlatan? Maybe. But I doubt it would bring the whole edifice crashing down.

    Me, I don’t know if Mann was deliberately deceptive. Seems unlikely.

    On the basis of what? Your gut feeling? The way the wind blows today? No-one that bald could tell a bald-faced lie? There are facts beyond dispute that show that Mann has repeatedly lied in scientific publications as well as to investigations setup at the behest of Congress. Unless you’re claiming he was mentally incapable of distinguishing right from wrong then you’re simply blowing too hard.

    I don’t have to “believe” in global warming one way or another to grasp those facts. For you, its all visceral, all emotional, all intestinal. But guess what? There are no brains located there.

    But I do know that it doesn’t matter a damn except in the fevered world of rabid loathing for the notion of AGW.

    …and its back to political viewpoints trumping facts. “Fevered loathing” is in the eye of the beholder and is common in the fact-free American Smashmouth political dialogue that passes for debate.

    “Is Joe Romm producing more fevered loathing than Mark Morano? Al Gore more than Rush Limbaugh? Liberals call 1-800-WE-H8T-REPUBS and Conservatives call 1-800-WE-H8T-LIBRALS and have your say! Calls cost $1 per minute and lines are open right now!!!!”

    What I do know is that Mann did not get rid of the MWP or LIA, and that Smokey’s chart completely undermines the point he’s trying to make while corroborating Mann’s (and the majority in paleoclimate) view of a MWP that was not synchronous. I can correct the obvious stuff. If you think you’re all over the nuances, more strength to you. I’ve read the reports, too and Steve Mc, and I still don’t think I’m qualified to judge. Your assertions do no more to persuade than the denser material I’ve read.

    If you think about it, seasonal warmth and cold are not hemispherically synchronous if you use proxies for precipitation, or heat, or growing season, or sea-ice coverage. I don’t expect the answer to be as simple as reading a thermometer.

    But I do know that large numbers of the people who claim that what they have done is meaningful or massively accurate as thermometers are either deluded or liars based on the evidence presented.

    I’m not defending Mann. Screw him. I’m just trying to set the record straight where it’s obviously wrong.

    How can you be possibly not defending Mann if you haven’t found anything wrong with what he’s done and spend so much time and effort to tell us how mistaken we are about him?

    Perish the thought.

  97. Kevin MacDonald, please don’t post bogus charts like that.

    We can see that the MWP was warmer in the larger chart you posted. So to make current temperatures appear warmer, your small inset chart shows massive warming since 2004. But that has not happened. Temperatures have been flat to declining for the past fourteen years. Over the past two years temperatures have been falling.

    Also, the evidence clearly shows that there were even warmer periods prior to the MWP; another confirmation of the null hypothesis.

    The fact that curent temperatures are extremely mild deconstructs the wild-eyed beliefs of the alarmist crowd. There simply isn’t anything to be alarmed about.

    CO2 is a harmless and beneficial tiny trace gas. More CO2 is better. What is really scary is the possibility of glaciation resuming. If that happens, worldwide starvation will be widespread and commonplace. You’re worrying about exactly the wrong thing. Warmer is better. Cold kills!

  98. How can Smokey say anything definitive about global warming, which has everything to do with chemistry. Let me quote an earlier post of his:


    RB says:

    “Just because one time in the whole post i omitted dioxide by accident, doesn’t mean I don’t know what an element or a molecule is.”

    Actually, CO2 is a compound.

    Good luck passing your chem lab.☺

    And before you all start pulling out your dictionaries (or in the case of Smokey, Wikipedia), let me tell you what a compound REALLY is:

    A compound is at least two different elements. A molecule is just two or more atoms. All compounds are molecules but not all molecules are compounds, for example: H2, Cl2, O2, etc. It’s not wrong to call CO2 a compound, but its definitely wrong to say it isn’t a molecule.

    He disappeared from another thread after I refused to be deflected from this point :)

  99. ^this was after he tried to strawman me on a typo LOL (I talked about carbon dioxide about twenty times in the post, and one was missing the “dioxide” on the end). He proceeded to completely ignore everything else and attack that haha

  100. Robert Bertino,

    Please list your “twenty times’ in your comments. The fact is that your hair-splitting is simply obfuscation. Read all the other comments here that deconstruct your wild-eyed alarmism. They are right. Where does that leave you?

    Let’s get back to the point: the MWP was warmer than today. And prior warmings were even warmer than the MWP – thus deconstructing your CAGW fantasy. Your CO2=CAGW argument thus fails; scientific skeptics have won the debate. Deal with it.

  101. ^ even now, you still deflect my point. Answer this VERY simple question. How can you claim to have the expertise and scientific know-how to make judgments about Global Warming, which is a chemical and physical process, if you don’t even know what a molecule is? What’s worse was the fact that you not only spoke with authority when you said that, you insulted me for not knowing my chemistry (when you didn’t have any ground to stand on). It’s a fair question, and I would like to see it answered.

  102. and the post in question:

    “Warming of ocean waters takes place at the surface in the sunlight, so a little bit of the CO2 is released at first from the water. However, the water isn’t as cool as it once was, so when it reaches high latitudes, it takes up less CO2 than normal and it does not sink as deeply. Because of this disruption in the ocean currents, the deep cold water doesn’t participate as much in vertical circulation and tends to stagnate. Life on the sea floor (and organic matter falling from above) produces more CO2 through cellular respiration, but since oxygen is no longer being delivered as adequately, we have anaerobic respiration where nitrate is used by bacteria as a source of oxygen instead. During this process, nitrous oxide and molecular nitrogen are made. What happens in the end: because the oceans have warmed and currents have slowed down, we have effectively created a vast ocean reservoir rich in CO2 but poor in nutrients. When this water returns to the surface, it will now bring CO2 back into the atmosphere, unable to recapture it through photosynthesis, due to a lack of nutrients.

    ^This process contributes to the “pulsed” nature of CO2 rise during de-glacialation, as we have seen in the ice cores. Additionally, we can easily see how this cycle would result in a positive feedback loop in regards to rising average temperatures.”


    You can notice how at the end i talk about the pulsed nature of CO2. Then in another post (the one you attack me for, I say:

    “And btw, If you read my post fully, you would notice that I talked about carbon’s “pulsed nature”.”
    then you: “Carbon”?? As in CO2, a trace gas? FYI: carbon is an element.”

    There you go. An 8 year old could see that was a typo.

  103. Smokey says:

    “We can see that the MWP was warmer in the larger chart you posted.”

    No you can’t, no reconstruction show a MWP globally warmer than now.

    Smokey says:

    “So to make current temperatures appear warmer, your small inset chart shows massive warming since 2004. But that has not happened.”

    The “small inset chart” shows temperatures for the entire Holocene, your terms of reference, not mine, and, because of the low resolution in reconstructions over this period, it doesn’t show recent warming at all, it merely shows the 2004 temperature for comparison with average temperatures over the entire period. Clearly current global temperatures are higher than the those generally experienced during the holocene, so by your own definition; “If one or more of the parameters of the Holocene were exceeded, then the null hypothesis would be falsified”,/i>, the null hypoethesis has been falsified.

    Smokey says:

    “Temperatures have been flat to declining for the past fourteen years.”

    No they haven’t, although I presume you’re cherry picking 1998 as your start date, despite the fact we don’t have a full fourteen years of data from them, and, even then, only one of the data sets shows a flat or declining trend for that period. And that is before we get on to ocean heat content which has continued to increase during that period.

    Smokey says:

    “Over the past two years temperatures have been falling.”

    Seriously, you castigate me for moving from an 800 thousand year record to a 12 thousand year one (this in spite of the fact the 12 thousand year period, the Holocene, was introduced by you), but think it is okay for you to refer to only two years of data?

  104. Kevin MacDonald,

    I know why you’re wrong about everything. It’s because you believe the nonsense you pick up from Skeptical Pseudo-Science and similar propaganda blogs. Those are fantasy charts you’re posting. When evidence based charts are used, it is clear that there have been warmer periods during the Holocene. The spaghetti graph you posted is the output of computer models and not worth spit. Using a chart based on empirical evidence it is obvious that past temperatures have exceeded those of the Modern Warming Period. Here’s another. And another. And an animation to put things in their proper perspective.

    The planet has warmed – naturally – from 288K to 288.8K in the past 150 years. Looking at the real world evidence of the wild swings in temperature over the past ten millennia, current temperatures are as close to static as you can find. And attributing that minuscule rise to CO2 is simply an argumentum ad ignorantium: “Since I can’t think of any other possible cause, then it must be due to CO2. How stupid.

    Next, go argue with Phil Jones about the non-existent warming. He’s the one who admitted it has stopped. And you still do not understand the null hypothesis. I give up. Apparently you are simply unable to grasp the basic concept that temperatures must exceed the parameters of the Holocene in order to falsify the null hypothesis. They haven’t even come close.

    Next, as I’ve repeatedly pointed out, using a phony zero or flat baseline instead of a trend line always results in a scary looking hockey stick shape. That’s why they do it. But when the trend since the LIA is used, it becomes clear that the trend is moderating [the green line], and that nothing unusual is occurring. The planet is simply warming from the LIA.

    Finally, your complaint about the 2-year chart I linked contains nothing of substance, so there is no need to reply. That chart says it all.

    • • •

    Robert Bertrino:

    Since you completely avoided answering the specifics in my last post, I’ll repost it. Please provide specific answers. I want to see those twenty times you claim:

    Please list your “twenty times” in your comments. The fact is that your hair-splitting is simply obfuscation. Read all the other comments here that deconstruct your wild-eyed alarmism. They are right. Where does that leave you?

    Let’s get back to the point: the MWP was warmer than today. And prior warmings were even warmer than the MWP – thus deconstructing your CAGW fantasy. Your CO2=CAGW argument thus fails; scientific skeptics have won the debate. Deal with it.

    To get any credibility and respect here at the internet’s “Best Science” site, start answering the specific points raised. So far, you’ve simply dodged.

  105. LOL smokey you are unbelievable. I can’t get a straight answer out of you!

    Here’s my previous post:

    even now, you still deflect my point. Answer this VERY simple question. How can you claim to have the expertise and scientific know-how to make judgments about Global Warming, which is a chemical and physical process, if you don’t even know what a molecule is? What’s worse was the fact that you not only spoke with authority when you said that, you insulted me for not knowing my chemistry (when you didn’t have any ground to stand on). It’s a fair question, and I would like to see it answered.

    And I didn’t avoid your question about the “twenty times”, I put up the post in question for all to see. And I even put two parts of those posts side by side:


    1.
    This process contributes to the “pulsed” nature of CO2 rise during de-glacialation, as we have seen in the ice cores. Additionally, we can easily see how this cycle would result in a positive feedback loop in regards to rising average temperatures.”

    2.
    “And btw, If you read my post fully, you would notice that I talked about carbon’s “pulsed nature”.”

    Then you say in response to post 2: “Carbon”?? As in CO2, a trace gas? FYI: carbon is an element.”
    Viewing those side by side, how can you say that the second one was not a typo?

    Seriously smokey, I just want you to answer for this single quote of yours:

    Actually, CO2 is a compound.

    Good luck passing your chem lab.☺

    When I was talking about CO2 as a molecule. Just answer this question smokey. How can you claim to have the expertise and scientific know-how to make judgments about Global Warming, which is a chemical and physical process, if you don’t even know what a molecule is? And don’t disappear again like you did on the other thread.

  106. Bobbie Bertino says:

    “And I didn’t avoid your question about the ‘twenty times’, I put up the post in question for all to see. And I even put two parts of those posts side by side”

    Humor me. Post verifiable citations to your claim of “twenty times”. It’s your credibility that’s at stake here, junior. So link to each of your ‘twenty’. Or else everyone will see that you were fabricating your claim.

  107. Smokey says:

    “I know why you’re wrong about everything. It’s because you believe the nonsense you pick up from Skeptical Pseudo-Science and similar propaganda blogs. Those are fantasy charts you’re posting. “

    The graph I linked to uses the same empirical evidence your link does:

    Molecular stratigraphy of cores off northwest Africa: Sea surface temperature history over the last 80 Ka.;
    Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica;
    The Younger Dryas cold interval as viewed from central Greenland;
    Kilimanjaro Ice Core Records: Evidence of Holocene Climate Change in Tropical Africa;
    Synchroneity of Tropical and High-Latitude Atlantic Temperatures over the Last Glacial Termination;
    Eight glacial cycles from an Antarctic ice core;
    Decline of surface temperature and salinity in the western tropical Pacific Ocean in the Holocene epoch.

    Smokey says:

    When evidence based charts are used, it is clear that there have been warmer periods during the Holocene. The spaghetti graph you posted is the output of computer models and not worth spit. Using a chart based on empirical evidence it is obvious that past temperatures have exceeded those of the Modern Warming Period.”

    Not within the Holocene (that’s the 0-12,000 years before present in the graph you linked to) and that was era you specified for your null hypothesis.

    Smokey says:

    “Here’s another. And another. And an animation to put things in their proper perspective “

    None of these are global data sets, on their own they tell us nothing about global warming.

    Smokey says:

    “Next, go argue with Phil Jones about the non-existent warming. He’s the one who admitted it has stopped. “

    No he didn’t, this is what he actually said; “I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive”.

    Smokey says:

    “Apparently you are simply unable to grasp the basic concept that temperatures must exceed the parameters of the Holocene in order to falsify the null hypothesis. They haven’t even come close.

    Another graph that doesn’t show global temperatures? Can I remind you that we aren’t actually discussing Anthropogenic Vostock Warming.

  108. Here is a history of my quotes:

    {{{{{{{{{{{{{{

    Robert Bertino says:
    October 30, 2011 at 6:29 pm
    @Smokey
    “That one has been thoroughly debunked: effect cannot precede cause. On all time scales, CO2 is a function of temperature, not vice-versa.”
    I’m sorry but that is completely retarded. It’s basic physics. CO2 traps heat. End of story. Anybody with a glass tank, thermometer, and light can prove that.
    REPLY: LOL! Have a look at that exact experiment you describe:http://wattsupwiththat.com/2011/10/18/replicating-al-gores-climate-101-video-experiment-shows-that-his-high-school-physics-could-never-work-as-advertised/
    1. Robert Bertino says:
    October 30, 2011 at 10:05 pm
    ^the experiment is deeply flawed.
    lol even read his “update” at the end of the post, which most are unlikely to read:
    “I should make it clear that I’m not doubting that CO2 has a positive radiative heating effect in our atmosphere, due to LWIR re-radiation, that is well established by science. What I am saying is that Mr. Gore’s Climate Reality Project did a poor job of demonstrating an experiment, so poor in fact that they had to fabricate portions of the presentation, and that the experiment itself (if they actually did it, we can’t tell) would show a completely different physical mechanism than what actually occurs in our atmosphere.”
    If you want to know what a good CO2 experiment is like, check out this link:

    http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&sqi=2&ved=0CCIQFjAA&url=http%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fdownload%3Fdoi%3D10.1.1.117.2153%26rep%3Drep1%26type%3Dpdf&ei=nimuTpnMJ8OciQK9-ZSXCw&usg=AFQjCNHgeMEf_j5Utxoq1gdsTFdc-lki7A&sig2=pbI1QKWr0IhHXGjwmTLi2Q

    (It’s a PDF file)

    2. Robert Bertino says:
    October 30, 2011 at 11:10 pm
    “I should make it clear that I’m not doubting that CO2 has a positive radiative heating effect in our atmosphere, due to LWIR re-radiation, that is well established by science. What I am saying is that Mr. Gore’s Climate Reality Project did a poor job of demonstrating an experiment, so poor in fact that they had to fabricate portions of the presentation, and that the experiment itself (if they actually did it, we can’t tell) would show a completely different physical mechanism than what actually occurs in our atmosphere.”
    really must I quote what Watts himself said in his own articles again?
    3. Smokey says:
    October 31, 2011 at 10:53 am
    Robert Bertrino,
    Nice dodge. Falsification fail. OTOH, the quote you posted is accurate and factual.
    4. Robert Bertino says:
    October 31, 2011 at 9:10 pm
    “That one has been thoroughly debunked: effect cannot precede cause. On all time scales, CO2 is a function of temperature, not vice-versa.”
    Nice dodge on your side smokey, care to explain how the above quote and what Watts said can both be “accurate and factual”. And btw, the experiment i linked to was not meant to be the be all and end all of CO2 experiments, it was just an easy experiment that anybody (you) could do. If you actually read it for example, you’ll notice that having a lid on the container actually ruins the experiment.

    5. Robert Bertino says:
    October 31, 2011 at 9:41 pm
    “I’m not doubting that CO2 has a positive radiative heating effect in our atmosphere”
    ” effect cannot precede cause. On all time scales, CO2 is a function of temperature, not vice-versa.”
    View these side by side. How can CO2 have a positive heating effect but at the same time be a function of temperature? It’s totally contradictory.

    REPLY: You have no idea what you are talking about and frankly I’m too tired to explain it to you. But look it up yourself and report back – A


    Warming of ocean waters takes place at the surface in the sunlight, so a little bit of the CO2 is released at first from the water. However, the water isn’t as cool as it once was, so when it reaches high latitudes, it takes up less CO2 than normal and it does not sink as deeply. Because of this disruption in the ocean currents, the deep cold water doesn’t participate as much in vertical circulation and tends to stagnate. Life on the sea floor (and organic matter falling from above) produces more CO2 through cellular respiration, but since oxygen is no longer being delivered as adequately, we have anaerobic respiration where nitrate is used by bacteria as a source of oxygen instead. During this process, nitrous oxide and molecular nitrogen are made. What happens in the end: because the oceans have warmed and currents have slowed down, we have effectively created a vast ocean reservoir rich in CO2 but poor in nutrients. When this water returns to the surface, it will now bring CO2 back into the atmosphere, unable to recapture it through photosynthesis, due to a lack of nutrients.
    ^This process contributes to the “pulsed” nature of CO2 rise during de-glacialation, as we have seen in the ice cores. Additionally, we can easily see how this cycle would result in a positive feedback loop in regards to rising average temperatures.”

    }}}}}}}}}}}}}}}}}}}

    CO2 has been mentioned 16 times. I think its safe to assume that’s what I was talking about.

    And then I put these posts side by side:

    1.
    This process contributes to the “pulsed” nature of CO2 rise during de-glacialation, as we have seen in the ice cores. Additionally, we can easily see how this cycle would result in a positive feedback loop in regards to rising average temperatures.”

    2.
    “And btw, If you read my post fully, you would notice that I talked about carbon’s “pulsed nature”.”

    Then you say in response to post 2: “Carbon”?? As in CO2, a trace gas? FYI: carbon is an element.”
    Viewing those side by side, how can you say that the second one was not a typo?

    If anybody wants to see the comments in the thread, here’s the link: http://wattsupwiththat.com/2011/10/22/a-preliminary-assessment-of-bests-decline/#comment-787436
    It’s easy to find, smokey and I were the last ones talking.

    Seriously smokey, STOP AVOIDING MY QUESTION. You’re the one with credibility at stake here, junior.

    I just want you to answer for this single quote of yours:

    Actually, CO2 is a compound.

    Good luck passing your chem lab.☺

    When I was talking about CO2 as a molecule. Just answer this question smokey. How can you claim to have the expertise and scientific know-how to make judgments about Global Warming, which is a chemical and physical process, if you don’t even know what a molecule is? And don’t disappear again like you did on the other thread. The fact that you’ve been avoiding answering this question directly for the past week or so really say something, doesn’t it?

  109. Kevin MacDonald,

    The chart I posted doesn’t clearly show that past Holocene temperatures exceed current temperatures. But I’m here to help educate you, so…

    [Note: to avoid fake charges of cherrypicking, I’ve included charts with various time scales. Most, however, cover the Holocene.] :

    click1

    click2

    click3

    click4

    click5

    click6

    click7

    click8

    click9

    click10

    click11

    click12 [click in chart to embiggen]

    click13

    click14

    click15

    click16

    click17

    click18

    click19

    click20

    click21

    click22

    click23

    click24

    click25

    More charts provided upon request.

    Isn’t it frustrating when empirical evidence from both hemispheres debunks your true belief system? The fact is that current temperatures are normal, routine, and lower than past temperatures when CO2 was much lower.

    The failure to falsify the following hypothesis makes all the exaggerated hand waving over a tiny rise in temperature simpleminded alarmist nonsense:

    At current and projected concentrations, CO2 is harmless and beneficial.

  110. I see what your strategy is. The best offense is a good defense. You hope that by attacking me, the questions I have asked you can remain unanswered. Then if I defend myself, you’ll just bolt back into another discussion. I’ll humor you for a second, let’s say I’m the stupid, ignorant, true believer you say I am. Ok. That still doesn’t change what you yourself said.

    Seriously smokey, STOP AVOIDING MY QUESTION. You’re the one with credibility at stake here, junior.

    I just want you to answer for this single quote of yours:

    Actually, CO2 is a compound.

    Good luck passing your chem lab.☺

    When I was talking about CO2 as a molecule. Just answer this question smokey. How can you claim to have the expertise and scientific know-how to make judgments about Global Warming, which is a chemical and physical process, if you don’t even know what a molecule is? And don’t disappear again like you did on the other thread.

  111. Bobbyboy,

    I’m disregarding your posts for a good reason: unlike MacDonald’s, they are content-free. Mr MacDonald at least tries arguing the alarmist case, while you’re fixated on me. I could push your buttons some more, but why bother? As Anthony rightly pointed out: “You have no idea what you are talking about and frankly I’m too tired to explain it to you.” No one else talks about “pulsed” CO2. If that silly notion ever gained traction I would respond. So far, though, it’s just more alarmist lunacy, and you are the only one promoting it here.

    My guess is that you’re a lonesome twenty-something who actually believes he knows what he’s talking about; wrong. Immaturity runs throughout your comments [eg: ‘I know you are, but what am I?’], so I’ll stick to deconstructing MacDonald’s assumptions. Your lunatic “pulsed CO2″ fantasies are so far out of the mainstream they’re not worth responding to. And don’t get the idea that I’m responding to either you or MacDonald. I’m simply setting the record straight for readers who are still trying to figure out if they should be worried about rising CO2 or not. I’m showing them with peer reviewed information that there isn’t anything to worry about. If you want to add value to the discussion try to falsify my hypothesis instead of avoiding it at all cost.

  112. Even if I am the stupid, ignorant, true believer you say I am, it doesn’t change what you said.

    STOP AVOIDING MY QUESTION.

    I just want you to answer for this single quote of yours:

    Actually, CO2 is a compound.

    Good luck passing your chem lab.☺

    When I was talking about CO2 as a molecule. Just answer this question smokey. How can you claim to have the expertise and scientific know-how to make judgments about Global Warming, which is a chemical and physical process, if you don’t even know what a molecule is? It’s a fair question smokey. You attempt to present as somebody knowledgeable in the field of climate science. I want you to reconcile that fact with what you said earlier, that CO2 wasn’t a molecule. How can you even have a good “hypothesis” when you don’t know this?

  113. Bobby says:

    “STOP AVOIDING MY QUESTION.”

    It gives me much amusement to push young Bobby’s buttons.☺☺☺

  114. Smokey says:

    “More charts provided upon request.”

    Can you provide one that show global temperatures during the Holocene have been warmer than they are now? None of the ones you have linked to so far do, most of them show Vostock or GISP2, two locations in the Arctic – hardly global – and the only other graph with a source is Lhehel 2007 which was subsequently ammended when it was discovered that it exaggerated the MWP

  115. Kevin MacDonald,

    Glad you asked. Here is a global map of interactive charts showing the global impact of the MWP. Put your cursor on any of the charts for an expanded version.

    And here is a good article that debunks the nonsense that the MWP wasn’t a global event.

    There is a close correlation between Northern and Southern Hemisphere ice core evidence, therefore the temperature variations were global.

    And to repeat: there were global warming events prior to the MWP that were warmer than the MWP, and when CO2 was very low. And there were global glaciations when CO2 was very high. The logical conclusion: current temperatures are a function of natural variability, not changes in CO2.

  116. You obviously don’t want to answer the question, because the answer is uncomfortable. But no matter. You know and I know. Somebody who doesn’t know the difference between compounds and molecules isn’t qualified to make assessments about the state of climate science.

    And one annoying thing I’ve noticed about you from your posts in multiple threads:

    You really like going into third person mode a lot. “Robert Bertino is this”, “Kevin MacDonald is that”. Is that supposed to be more of an insult than saying it directly to our faces? lol

  117. Robert Bertino repeatedly claims that I don’t know the difference between a molecule and a compound. Having spent a 30+ year carreer working with many other engineers designing, calibrating and repairing weather related instruments, I could assure the young Mr Bertino [if I were responding to him] that I have probably forgotten more than the youngster has ever learned up to this point.

    Now, if someone wanted to provide a reasonable criticism of me that I would happily agree with, it would be that I get some amusement from pushing Bobby’s buttons and causing him to furiously post one impotent, demanding comment after another, as he has been doing. IMHO Bobby needs a girl friend. The kind he doesn’t have to inflate.☺

  118. Smokey says:

    “Glad you asked. Here is a global map of interactive charts showing the global impact of the MWP. Put your cursor on any of the charts for an expanded version.”

    That is a map that shows various regional warming trends that aren’t globally synchronous and, thus, is’t actually what I asked for; a chart that shows global temperatures, within the Holocene, that are warmer than today.

    Smokey says:

    “And here is a good article that debunks the nonsense that the MWP wasn’t a global event.”

    Nice straw man, but I haven’t been arguing for a globally asynchronous MWP, only that it wasn’t warmer that the last 100 years.

    Smokey says:

    “And to repeat: there were global warming events prior to the MWP that were warmer than the MWP, and when CO2 was very low. And there were global glaciations when CO2 was very high. The logical conclusion: current temperatures are a function of natural variability, not changes in CO2.”

    Moving the goal posts now? Here is your earlier null hypothesis; ““If one or more of the parameters of the Holocene were exceeded, then the null hypothesis would be falsified.”” Do you now accept that this has been falsified and, if not, will you ever actually provide evidence for a time in the Holocene when it was actually warmer that it is now?

  119. Kevin MacDonald,

    You still do not understand the null hypothesis! Amazing. I’m giving up on you since you can’t grasp the concept. The Holocene covers the past ten millennia, not just the MWP. There was the Minoan Optimum, the Roman Optimum, etc., which were warmer than the MWP. I’ve posted dozens of charts, including several charts of Holocene temperatures based on peer reviewed data from major journals that are accepted everywhere – and you still refuse to accept any of them [babbling instead about a mythical “Lhehel”]. Your mind is made up and closed tight. All you’re doing is arguing for the sake of argument, like your junior sidekick Bobby.

    Since you refuse to accept any of the ample verifiable, empirical, peer reviewed evidence I’ve provided, it’s clear that your true religious faith in CAGW pseudo-science is unshakable. You’re no different from a member of Leon Festinger’s Seekers: the flying saucer didn’t arrive as predicted. But does that mean there’s no flying saucer? Of course not! Mrs Keech just made a new prediction, and the flying saucer will arrive then. True Believers in CAGW are no different. Their predictions are wrong, but just you wait, that runaway global warming is right around the corner. As if.

    This thread has been fun, but trying to educate lunatics is a Sisyphean task [I note the moon is full]. So I’ll be moving on to a current thread; this one is almost a week old. True Believers can stick around here. Mrs Keech’s acolytes didn’t abandon her when the flying saucer failed to arrive, either.

  120. ^and your criticisms of Kevin are unfair. You post your stuff, saying its accurate and factual, while at the same time, Kevin posts his and you dismiss them as “fantasy charts” without actual delving into any specifics.

  121. Kevin MacDonald says:
    November 10, 2011 at 5:32 pm

    Exactly what part of the evidence of warmer temperatures during the Holocene than Present did you not understand?

  122. Kevin MacDonald says:
    November 11, 2011 at 5:32 am
    The lack of it. None of Smokeys graphs show global temperatures higher than modern times.

    The graphs depitct higher temperatures than Present, so how are they not “global temperatures higher than modern times”?

  123. ^Kevin is right. Global warming is a global phenomena, measurements from one point don’t change anything. Some areas will get colder, others hotter, but what we will see is a net temperature rise globally. Systems that trap more heat energy in them have more extreme (in variation) climates.

  124. But not warmer than current global temperatures (Loehle submtted revised figures when errors exaggerating the MWP were discovered in the original) and that is rather the point.

  125. Kevin MacDonald says:
    November 11, 2011 at 8:05 am
    They are not global in scope, they are
    measurements from a single geographic point.

    Aside from areal sensing measurements made from Earth orbit by satellite instrumentation for example, the vast majority of direct and proxy temperature measurements are “from a single geographic point.” Excluding such “a single geographic point” from the data record would in effect exclude nearly all of the modern instrumental records other than remote sensing systems such as aerial and space remote sensing measurements. That would make no rational sense. Did you perhaps mean to say the charts are not global in scope because they were not measurements from both hemispheres or multiple continents around the globe?

    If so, it appears you are deceived by the talking points taken from the false information provided by Grist in its “How to Talk to a Climate Skeptic: Responses to the most common skeptical arguments on global warming” website.

  126. Robert Bertino says:
    November 11, 2011 at 12:08 pm
    ^Kevin is right. Global warming is a global phenomena, measurements from one point don’t change anything. Some areas will get colder, others hotter, but what we will see is a net temperature rise globally. Systems that trap more heat energy in them have more extreme (in variation) climates.

    So, why then do you deny all of the evidence of the climate Optimums reported to have occurred during the Holocene and Pleistocene with higher than Present temperatures in the Northern Hemisphere, Southern Hemisphere, Eastern Hemisphere, Western Hemisphere, and all or nearly all continents?

  127. Another straw man, I’m not arguing that any data set be excluded, but pointing out that unless they are combined with data sets from other regions a single data set is useless for inferring global temperatures.

  128. Kevin MacDonald says:
    November 11, 2011 at 2:09 pm
    But not warmer than current global temperatures (Loehle submtted revised figures when errors exaggerating the MWP were discovered in the original) and that is rather the point.

    Why are you using Loehle as a false strawman argument, when the evidence for the earlier Holocene temperatures greaer than Present has nothing to do with Loehle?

  129. Kevin MacDonald says:
    November 11, 2011 at 3:40 pm
    Another straw man, I’m not arguing that any data set be excluded, but pointing out that unless they are combined with data sets from other regions a single data set is useless for inferring global temperatures.

    You were not presented with a strawman argument. You made the strawman argument when you falsely wrote: “None of the ones you have linked to so far do, most of them show Vostock or GISP2, two locations in the Arctic – hardly global – and the only other graph with a source is Lhehel 2007 which was subsequently ammended when it was discovered that it exaggerated the MWP.” You misspelledd Vostok as “Vostock”, and you falsely said the Vostok ice core came from the Arctic, which is of course at the top of the Northern Hemisphere. In the real world, the Vostok ice core came from the Antarctic at the bottom of the globe in Eastern Antarctica and at the opposite side of the world from the GISP2 ice core in the continent of Greenland. Although an argument may be made the two ice cores are not perhaps representative of the global temperature trend for the entire Earth, it is a total lie arising either from careless neglect or deliberate intent to misrepresent the two ice cores as coming only from the Arctic, which is in just the Northern Hemisphere. It was because of this glaring falsehood upon your part about the Vostok ice core which made it necessary for me to attempt to determine exactly what you do and do not mean in your words and phrasing when you use such terminology as “They are not global in scope, they are measurements from a single geographic point.” After all, you have just demonstrated your inability to tell the difference between the top and bottom of the globe by erroneously claiming the Vostok ice core project was in the same Arctic region as the GISP2 project in Greenland.

    The Earth was warmer overall at times during the Medieval Warm Period (MWP), but even if you exclude each and every report about the MWP, you still have to deny the evidence of higher temperatures than Present in each of the preceding global climate Optimums as well. You certainly are not going to have any success at denying those reports by falsely pretending there is no evidence of such temperatures at widely separated locations on many continents in both hemispheres of the Earth.

  130. D. Patterson says:

    “You were not presented with a strawman argument.”

    Yes I was, you claimed I was arguing for the exclusion of certain proxies or data sets from the temperature record when I was in fact arguing that individual proxies are of no use in inferring global in and of themselves. Mischaracterisation of an opponents argument is the definition of straw man

    D. Patterson says:

    “You made the strawman argument when you…falsely said the Vostok ice core came from the Arcti”

    An error on my part, for which I apologise, but not a straw man as it in no way misrepresents my opponents case – that current temperatures fall within the parameters of the Holocene – where Vostok actually is (or how its spelled) is not important, the fact remains that we can’t infer global temperatures from the temperatures at a single point on the globe we have to combine the various proxies to give us fuller coverage and none of the graphs Smokey linked to do this.

    D. Patterson says:

    The Earth was warmer overall at times during the Medieval Warm Period (MWP)”

    There is no evidence to support this assertion.

    D. Patterson says:

    “You certainly are not going to have any success at denying those reports by falsely pretending there is no evidence of such temperatures at widely separated locations on many continents in both hemispheres of the Earth.”

    Again, I’m not arguing that the evidence does not exist, I am arguing that no given proxy, in isolation, can be used to infer global temperatures, proxies have to be combined, thusly, with others from different regions to show the global picture. Nobody on this thread has linked to a multi proxy data set showing global temperatures during the holocene higher than today’s.

  131. Kevin MacDonald says:
    November 12, 2011 at 1:39 am
    D. Patterson says:

    “You were not presented with a strawman argument.”

    Yes I was, you claimed I was arguing for the exclusion of certain proxies or data sets from the temperature record when I was in fact arguing that individual proxies are of no use in inferring global in and of themselves. Mischaracterisation of an opponents argument is the definition of straw man

    So, if you understand a strawman argument is the “mischaracterization of an opponents argument,” then why do you mischaracterize my asking you whether or not it was true you DID NOT mean to say it illogically as a strawman argument? Notice I made no assumption you actually meant what you could have ambiguously wrote, But instead asked you to clarify that you did not mean the literal interpretation of what you wrote. I extended you the courtesy of NOT interpreting your writing contrary to your intent, and yet your response is to wrongly attempt to claim I did so to create a strawman argument.

    D. Patterson says:

    “You made the strawman argument when you…falsely said the Vostok ice core came from the Arcti”

    An error on my part, for which I apologise, but not a straw man as it in no way misrepresents my opponents case – that current temperatures fall within the parameters of the Holocene – where Vostok actually is (or how its spelled) is not important, the fact remains that we can’t infer global temperatures from the temperatures at a single point on the globe we have to combine the various proxies to give us fuller coverage and none of the graphs Smokey linked to do this.

    You claim that you did not make a strawman argument because “it in no way misrepresents my opponents case….” On the contrary, your error did misrepresent Smokey’s case, by conflating two temperature records into just the Arctic region of the Northern Hemisphere, deceiving any uninformed readers into believing Smokey’s information did nothing whatsoever to represent the temperatures outside of the Arctic and the Northern Hemisphere. The reality on the other hand is a temperature record indicating warmer temperatures at the top and bottom of the world, the Arctic and the Antarctic, the Northern Hemisphere and the Southern Hemisphere. As I wrote before, it may be possible to argue having only two locations in the world at opposite ends of the Earth does not provide full coverage, it makes a world of difference in significance when the two measurements come from opposite sides of the world. Although these two measurements omit coverage of the temperate latitudes and the tropical latitudes, they do indicate the two measurements are more consistent with a wamer world in which these intermediate temperature measurements are absent from the charts than it does a world in which the world was not warmer in the same two locations regardless of whatever the intermediate latitudes could have been. Consequently, your error did result in a strawman argument by denying the fact that having the two measurements at the planet’s opposite poles eliminated the possibility the warmer temperatures occurred only in the Arctic of the Northern Hemisphere.

    D. Patterson says:

    The Earth was warmer overall at times during the Medieval Warm Period (MWP)”

    There is no evidence to support this assertion.

    You were supplied with evidence that comes from every continent on the Earth, and still you deny this after making the error of assuming the Vostok project was in the Arctic. Perhaps you would care to explain how each of these points of measurement from continents all around the Earth are not satisfactory?

    D. Patterson says:

    “You certainly are not going to have any success at denying those reports by falsely pretending there is no evidence of such temperatures at widely separated locations on many continents in both hemispheres of the Earth.”

    Again, I’m not arguing that the evidence does not exist, I am arguing that no given proxy, in isolation, can be used to infer global temperatures, proxies have to be combined, thusly, with others from different regions to show the global picture. Nobody on this thread has linked to a multi proxy data set showing global temperatures during the holocene higher than today’s.

    It appears you are making a false statement. Smokey posted a link to a website displaying numerous sites for such temperature data sets. Let us see you refute each of those sources, before you make such sweeping statements denying their existence. Furthermore, other posters posted other individual datasets obtained in different parts of the world. Then there are the various sources not yet mentioned in the thread for the Medieval Warm Period (MWP). Beyond the MWP there are also the sources for the other climate Optimums which you have not even made any effort to address, whether or not they were mentioned in this thread.

    You can begin by refuting the individual sources in Africa and South America for the MWP.

  132. D. Patterson says:
    “You can begin by refuting the individual sources in Africa and South America for the MWP.”

    I’ve already done this, that was the point of the multi-proxy graph I linked to; it shows that the warming events depicted in the individual proxies were regional rather than global in scale, if they were globally synchronous then that would show in multi-proxy reconstructions as a temperature point higher than current levels.

  133. D. Patterson is correct when he states that there is evidence that the Earth was warmer overall at times during the Medieval Warm Period. Dr. Loehle used eighteen different (non-tree ring) proxies, all of them peer-reviewed, and all showing MWP temperatures as high or higher than present global temperatures. Please see the links in my previous post.

    There is globally synchronous multi-proxy evidence showing unequivocally that prior warm periods were in fact warmer than today’s temperatures. The IPCC showed this in AR-1:

    Since then there has been a concerted effort by some to rewrite the geological evidence. That effort has not gained traction because the multi-proxy evidence from multiple ice cores in both hemispheres shows definitively that the earth has been warmer, sometimes considerably warmer than now.

  134. Kevin MacDonald says:
    November 12, 2011 at 11:35 am
    D. Patterson says:
    “You can begin by refuting the individual sources in Africa and South America for the MWP.”

    I’ve already done this, that was the point of the multi-proxy graph I linked to; it shows that the warming events depicted in the individual proxies were regional rather than global in scale, if they were globally synchronous then that would show in multi-proxy reconstructions as a temperature point higher than current levels.

    Actually, you have done nothing of the sort. You haven’t even identified the individual sources, much less shown you understand what areas of the planet they represent. Remember, the Vostok project is an austral locale and not a boreal locale as you tried to claim. Can you even give a correct identification for the source of your graph and each of its data sources? No handwaving, broad generalizations, or pile of bibliographic references. What is the specific source and authority for each claimed dataset? What sources opposed the conclusions of the paper and why?

  135. Let me ask you guys a question. Why is Venus hotter than Mercury?

    REPLY: Let me ask you a question, is Earth Venus?

    Give it up – it’s getting old, this thread will close soon – Anthony

  136. Dr. Everett V. Scott says:

    “D. Patterson is correct when he states that there is evidence that the Earth was warmer overall at times during the Medieval Warm Period. Dr. Loehle used eighteen different (non-tree ring) proxies, all of them peer-reviewed, and all showing MWP temperatures as high or higher than present global temperatures. Please see the links in my previous post.

    There is globally synchronous multi-proxy evidence showing unequivocally that prior warm periods were in fact warmer than today’s temperatures. The IPCC showed this in AR-1:

    http://jonova.s3.amazonaws.com/guest/de/temps-ar1.jpg

    Both the Loehle paper and the graph linked above terminate in the early part of the 20th century. There has beed some 0.8°C of warming since then taking current temperatures above those shown for the MWP.

    Dr. Everett V. Scott says:

    “multi-proxy evidence from multiple ice cores in both hemispheres shows definitively that the earth has been warmer, sometimes considerably warmer than now.”

    During the Holocene? Those were Smokey’s terms of reference. If so, post a link for these multi-proxy studies.

  137. Kevin MacDonald says:
    November 12, 2011 at 2:46 pm
    [….]
    During the Holocene? Those were Smokey’s terms of reference. If so, post a link for these multi-proxy studies.

    We’re still waiting for you to produce the sources for your “multi-proxy studies” to substantiate your fantastic chart. Perhaps you would care to produce that information and precisely define what you are claiming constitutes acceptable forms of “multi-proxy studies”, so we can avoid having you move the goalposts afterwards.

  138. Kevin MacDonald says:
    November 12, 2011 at 2:46 pm

    During the Holocene? Those were Smokey’s terms of reference. If so, post a link for these multi-proxy studies.

    Since I expect you are not debating in good faith and will never really attempt to substantiate your chart nor acknowledge any of the multi-proxy studies supportive of the HTM (Higher Than Modern) temperatures in the Holocene, I’ll go ahead and provide for the sake of other readers one of the many sources reporting such HTM levels.

    A large majority of the here investigated temperature reconstructions indicate that temperatures were warmer at the mid-Holocene (6000 BP±500 yrs) compared to the preindustrial period (1500AD±500 yrs), both in summer, winter and the annual mean. By taking simple arithmetic averages over the available data, the reconstructions indicate that the northern high latitudes were 0.9 #C warmer in summer, 0.5 #C in winter and 1.7 #C warmer in the annual mean temperature at the mid-Holocene (6 ka) compared to the recent pre-industrial.
    [….]
    Fig. 1. Map of the sites from which quantitative temperature and precipitation reconstructions from proxy data have been collected.
    [….]
    Fig. 3. Map of the estimated difference in temperature (annual, July, January) between 6 ka and 0.5 ka at the different proxy sites over the northern high latitudes.

    Sundqvist, H. S.; Zhang, Q.; Moberg, A.; Holmgren, K.; Kornich, H.; Nilsson, J.; and Brattstrom, G. Climate change between the mid and late Holocene in northern high latitudes – Part 1: Survey of temperature and precipitation proxy data. Received: 31 May 2009 – Published in Clim. Past Discuss.: 6 July 2009; Revised: 27 August 2010 – Accepted: 6 September 2010 – Published: 17 September. Published by Copernicus Publications on behalf of the European Geosciences Union.

  139. I linked to all the papers used to construct the graph earlier in this thread, that should clear up any ad hom’s about my good faith, and since I’m not arguing that there was no point during the Holocene warmer than the recent pre-industrial you can dispense with your latest straw man too.

  140. Kevin MacDonald says:
    November 13, 2011 at 1:24 am
    I linked to all the papers used to construct the graph earlier in this thread, that should clear up any ad hom’s about my good faith, and since I’m not arguing that there was no point during the Holocene warmer than the recent pre-industrial you can dispense with your latest straw man too.

    Like I said, you are not getting away with trollish forms of handwaving here. Identify the source of the graph you chose to use. If you are going to use someone else’s work and cite it as an authority, the least you can do is have the integrity to cite the author of the graph, the title of the work in which the graph appears, and the location in the work where it is to be found. We, of course, already know there are a number of different versions of the graphs you posted appearing at OSS Foundation, Wikipedia, and other alarmist websites. You still need to do the right thing and properly cite the author and work from whom you obtained each graph. Then you need to identify each graph line and cite the source/s for each graph line, one again citing the author, title, and location in the work/s.

    You are once again trying to foist another strawman argument by pretending the data is only about “recent pre-industrial”, when it is in fact about the Present and Now. The source I cited was for the readers, so don’t waste your time trying to spin the wording of that source to mean something else.

    And, no, you are still not debating in good faith at all. Given your obvious mistakes, we have evry reason to doubt you even know or understand who compiled your graph/s, what the graph lines mean, or understand the error ranges in the graph/s.

  141. The graph I posted had multiple sources and I’ve already submitted links to them all. The abstract you posted makes no reference to temperatures after the recent pre-industrial.

  142. Kevin MacDonald says:
    November 13, 2011 at 10:07 am
    The graph I posted had multiple sources and I’ve already submitted links to them all.

    Is that so? To eliminate any potential for an unfortunate misunderstanding of your intent and opportunity for you to switch graphs on us in mid-debate, show us exactly which graph for which you claim to “already submitted links to them all”?

  143. Kevin MacDonald says:
    November 13, 2011 at 1:01 pm
    I’ve only posted one graph of Holocene temperature anomalies.

    If so, then you should not have any trouble courteously repeating it here and now, or you can reference the date and time of your post for the benefit of all readers of this thread.

  144. Kevin MacDonald says:
    November 13, 2011 at 1:01 pm
    I’ve only posted one graph of Holocene temperature anomalies.

    Since you are dragging your feet, we’ll just have to give you a hand. Is this your “one graph of Holocene temperature anomalies” in your following post?

    “blockquote>Kevin MacDonald says:
    November 8, 2011 at 4:43 pm
    Smokey says:

    “If one or more of the parameters of the Holocene were exceeded, then the null hypothesis would be falsified.”

    Brian H says:
    November 7, 2011 at 10:57 p

    “What you said, Smokey.”

  145. Kevin MacDonald says:
    November 13, 2011 at 1:01 pm
    I’ve only posted one graph of Holocene temperature anomalies.

    Name the author of the “graph of Holocene temperature anomalies”

  146. Kevin MacDonald says:

    “…post a link for these multi-proxy studies.”

    I have, repeatedly. Here is a reference to eighteen NON-TREE RING PROXIES clearly showing a strong global MWP. They are not Dr Loehle’s peer reviewed papers; they are the peer reviewed papers of 18 independent scientists, compiled by Dr Loehle. You are simply rejecting out of hand all evidence that doesn’t conform to your belief system.

  147. Kevin MacDonald says:
    November 13, 2011 at 1:01 pm
    I’ve only posted one graph of Holocene temperature anomalies.

    You posted “one graph of Holocene temperature anomalies” which indicates higher temperatures than Present ealier in the Holocene. It is no wonder that you are being evasive about answering questions about your sources.

  148. Smokey says:
    November 13, 2011 at 8:35 pm

    It looks like Kevin MacDonald may be down in South America searching to find Greenland and GISP2. Perhpas he’ll stumble upon the lost civilization of Chile and report in to Steve McIntyre.

    It’s a pity we haven’t found some thermoscope records in a Greek or Roman monestary circa 3rd or 4th Centuries and earlier.

  149. Kevin MacDonald says:
    November 14, 2011 at 5:38 am
    The graph was created by Robert A Rohde, using studies I have already linked to, at no point on the graph does it show global anomalies higher than today and Loehle stops in 1935, looks like this if you add the missing years and clearly isn’t showing a MWP warmer than today.

    You are evidently as incompetent at reading your own graph and the article accompanying it from Wikipedia as you were incompetent at locating the Vostok project and Antarctica. The Wikipedia article starts in the Northern Hemisphere with:

    Of 140 sites across the western Arctic, there is clear evidence for warmer-than-present conditions at 120 sites. At 16 sites where quantitative estimates have been obtained, local HTM temperatures were on average 1.6±0.8 °C higher than present. Northwestern North America had peak warmth first, from 11,000 to 9,000 years ago, while the Laurentide ice sheet still chilled the continent. Northeastern North America experienced peak warming 4,000 years later. Along the Arctic Coastal Plain in Alaska, there are indications of summer temperatures 2–3C warmer than present.[5] Research indicates that the Arctic had substantially less sea ice during this period compared to present.[6]

    Wikipedia goes on to the Southern Hemisphere and found:

    In the far southern hemisphere (e.g. New Zealand and Antarctica), the warmest period during the Holocene appears to have been roughly 8,000 to 10,500 years ago, immediately following the end of the last ice age.[9][10] By 6,000 years ago, the time normally associated with the Holocene Climatic Optimum in the Northern Hemisphere, these regions had reached temperatures similar to those existing in the modern era, and did not participate in the temperature changes of the North. However, some authors have used the term “Holocene Climatic Optimum” to describe this earlier southern warm period as well.

    Although the Wikipedia article goes to great pains in an effort to characterize or mischaracterize the HTM (Higher Than Modern) temperatures as asynchronous regional warmings, it simply won’t work when the time periods overlap and when sources they omiitted are considered. Even the IPCC has acknowledged the HTM temperatures in the Holocene.

    IPCC Third Assessment Report – Climate Change 2001: Working Group I: The Scientific Basis; Chapter 2. Observed Climate Variability and Change. 2.4.2 How Stable was the Holocene Climate? […] The early Holocene was generally warmer than the 20th century but the period of maximum warmth depends on the region considered.

    So you may as well abandon your fantasy, because even your own sources and the IPC, the fountainhead of the AGW fraud say “The early Holocene was generally warmer than the 20th century[….]

  150. The wikipedia article is consistent with AR4, which says; “Due to different regional temperature responses from the tropics to high latitudes, as well as between hemispheres, commonly used concepts such as ‘mid-Holocene thermal optimum’, ‘altithermal’, etc. are not globally relevant and should only be applied in a well-articulated regional context.”

    The warming periods are not globally synchronous, no matter how you try to spin it.

    • Kevin,
      the AR4 is knowledge until 2006 (published 2007) and ever since many new
      studies in different locations have been made showing the syncronous climate
      in the NH and the SH. Concerning Wikipedia: The warmists are highly influencial expressing their view……thus a very doubtful source……
      On an general view: It started out in the ’80 with the so-called see-saw theory, with NH and SH warming and cooling alternately….. then, in the ’90, warmists went back a step, postulating: No more see-saw but its all regional, in any case: No syncronous temp. movement and…soon,.in a couple of years until 2020 they have to go further back (having lost, but wont concede yet today) and acknoledging the syncronous temps….. in NH and SH

  151. Joachim Seifert says:

    “Concerning Wikipedia: The warmists are highly influencial expressing their view……thus a very doubtful source…”

    On climate matters Wikipedia has no more credibility tha DeSmogBlog, Pseudo-Skeptical Pseudo-Science, tamino, Romm, etc. IMHO the despicable censoring propagandist William Connolley has no credibility whatever, but he still manages to censor comments he doesn’t agree with. That is not science, and anyone who appeals to Wikipedia’s incredible authority will certainly end up with a wrong-headed belief in catastrophic AGW.

  152. Yes, we know you dismiss, out of hand, any source that challenges your dogma, have you found one supporting it yet; a peer reviewed paper showing current temperatures are within the norm for the Holocene?

  153. Pure psychological projection, MacDonald. It is you who always dismisses out of hand every chart, graph, and link that I post. Furthermore, as usual you have the scientific method completely backward. The onus is on you to provide testable, falsifiable evidence showing that CAGW [or AGW for that matter] even exists. It may. But as of now, AGW is simply an evidence-free conjecture.

    I do not need a peer reviewed paper to falsify your claims, even though I’ve linked to plenty of them that do exactly that. And what is better than a peer reviewed paper? Glad you asked: empirical evidence is better. Ice cores are empirical, testable evidence. And ice cores from both hemispheres falsify your true belief system that current temperatures are ‘the hottest evah!’

    Once again I challenge you to try and falsify my testable hypothesis:

    At current and projected global concentrations, CO2 is harmless and beneficial.

  154. We’re testing your hypothesis that current temperatures fall within the parameters of the Holocene and you’ve been utterly unable to prove that, this is just you shifting the goal posts to try and hide that failure.

  155. MacDonald, you’re ‘testing’ nothing. You’re only putting words in a post that are nothing but your misinformed and provably wrong opinion. Time for you to run along back to Pseudo-Skeptical Pseudo-Science for some new talking points and moral support.

    There is ample evidence that there were warmer episodes throughout the Holocene. Abrupt warming of up to 27°F is recorded, when CO2 levels were very low; contrast that with the minuscule warming of 0.8° over a century and a half as the planet continues to emerge from the LIA.

    Your lame post is a simple strawman argument, which I destroyed with evidence-based facts. My own hypothesis is that more CO2 is harmless and beneficial. And as usual, you avoided taking my challenge.

  156. Those are all regional reconstructions, you are yet to provide a global one that supports your case and “global” is quite central to the global warming debate.

  157. Kevin MacDonald says:
    November 15, 2011 at 9:46 am
    “The warming periods are not globally synchronous, no matter how you try to spin it.”

    So, the IPCC says “The early Holocene was generally warmer than the 20th century”, and you acknowledge their statement is true?

  158. In AR3, because that was the best evidence at the time, that is no longer the case, hence my quoting from the IPCC’s current report.

  159. Kevin MacDonald says:
    November 16, 2011 at 1:42 pm
    In AR3, because that was the best evidence at the time, that is no longer the case, hence my quoting from the IPCC’s current report.

    You left out some important parts of what they had to say, but we’ll return to that issue later.

    For now, tell us which of the regions you do acknowledge as equaling and/or exceeding HTM temperatures of the Present?

  160. Kevin MacDonald says:
    November 16, 2011 at 1:42 pm

    No response yet? Perhaps you need a little help. Looking at regions which were warmer than Present in the Holocene, we find a few regions. Let’s see…how about North America, South America, Greenland, the Arctic, Europe, Asia, North Africa, South Africa, Australia, New Zealand, South America, and the Antarctic? What else…the West Pacific, the Mediterranean, the Norwegian Sea?

  161. Kevin MacDonald says:
    November 16, 2011 at 1:42 pm
    In AR3, because that was the best evidence at the time, that is no longer the case, hence my quoting from the IPCC’s current report.

    To answer the question about the regions which had HTM temperatures, you needed to look no farther than the same report you quoted. Like a naked person avoiding an ivy patch, you keep dodging the more inconvenient things the same report has to say. For one example:

    IPCC Fourth Assessment Report: Climate Change 2007: Working Group I: The Physical Science Basis. 6.5.1.3 Was Any Part of the Current Interglacial Period Warmer than the Late 20th Century? [….] Extratropical centennial-resolution records therefore provide evidence for local multi-centennial periods warmer than the last decades by up to several degrees in the early to mid-Holocene.

    The implications from other examples of what this same report had to say are rather problematic for your assertions and the report’s own comments. Why, do you suppose, your quotation and others in the report create conflicts with the report’s own sources?

  162. This is all irrelevant, nothing more than rhetorical posturing, we are discussing global temperatures, not regional ones, you are defending Smokey’s assertion that current global temperatures fall within the parameters of the Holocene, show me where this is true or concede the point.

  163. Kevin MacDonald suffers from incurable cognitive dissonance – what George Orwell called “doublethink”. Temperatures during the Holocene have been much higher than present. And much lower, too. Currently we are near the middle of the range; not even close to the parameters. But MacDonald incredibly believes that we are now outside Holocene parameters.

    No credible scientist disputes the fact that we are well within Holocene parameters. But Kevin MacDonald does. At WUWT we get to read what real climate scientists like Richard Lindzen and John Christy say. We also get to see what the nutcases say. Intelligent readers can sift the wheat from the chaff, and decide who is credible and who isn’t.

  164. Kevin MacDonald says:
    November 18, 2011 at 8:54 am
    This is all irrelevant, nothing more than rhetorical posturing, we are discussing global temperatures, not regional ones, you are defending Smokey’s assertion that current global temperatures fall within the parameters of the Holocene, show me where this is true or concede the point.

    The one thing we can agree upon is that you are indeed attempting to use “irrelevant, nothing more than rhetorical posturing,” in the face of overwhelming evidence of HTM temperature in the early and mid-Holocene across every continent on the face of this planet. If you think not, then feel free to point to one or more continents where the temperatures did not remain 0.5C to 2C or more greater than the Present. The question of whether or not these regional HTM temperatures were or were not truly HTM in a global average earlier in the Holocene depends upon the reliability of the regional datasets. Yet you are trying desperately to avoid a discussion of their reliability by the self-serving declaration that it is all “irrelevant” and “rhetorical” in their significance. Nothing could be further from the truth, of course, because any putative global average is composed of a number of lesser regional and local temperatures. You are in effect saying the data is irrelevant in the face of interpretive and subjective rhetoric in the AR4 report, which is totally backwards from reality.

    Now, please be kind enough to state exactly which of the regional and/or local temperature dataasets used to compile the supposed global average temperature which were NOT HTM temperatures during the Holocene, and cite each source of that dataset. We need to see whether or not we can agree upon the quantitative values of the temperatures and the means by which they were determined.

  165. Yet [you’re] are unable to point to a period during the Holocene globally warmer than the current era.

  166. Yeah, but you’re still citing regional variations despite the fact we’re discussing global ones, its like you’re addicted to straw man fallacies.

  167. Kevin MacDonald says:
    November 18, 2011 at 3:48 pm
    Yeah, but you’re still citing regional variations despite the fact we’re discussing global ones, its like you’re addicted to straw man fallacies.

    At the moment, we are discussing the source you cited as alleged support for your argument and what it had to say about the regional components it used to compile an overall global average. Nearly every regional component your source used to compile the global average temperature was a HTM temperature. They represented every continent on the planet. Since you are relying upon a statement claiming the overall global average is not HTM, we need to see which of the regional components used to compute the average we can agree upon as being less than HTM. Since you refuse to identify this evidence, it appears that you must not understand the evidence of your own source citation and/or fear it cannot withstand any scrutiny.

  168. The following charts are not intended for Kevin MacDonald. Kevin has cognitive dissonance and he will never agree with any facts that contradict his belief system. But for those who might still wonder if the MWP was global, these charts tell the story.

    First, there is plenty of evidence from both the Northern Hemisphere and the Southern Hemisphere showing that the planet warmed and cooled concurrently and therefore globally:

    click1
    click2
    click3

    Both hemispheres show simultaneous major warming and cooling events, indicating that the events were truly global in extent.

    Various locations showing temperature parameters:

    click1
    click2
    click3
    click4
    click5
    click6
    click7
    click8
    click9
    click10
    click11
    click12
    click13

    The belief that today is warmer than the MWP is based on tree ring proxies. However, tree rings are not very good at determining past temperatures [not to mention the shenanigans that Mann and Briffa engaged in by cherry-picking a small subset of available tree ring proxies; when the entire set is used along with the proper statistical methodology, the hockey stick shape entirely disappears]. Tree ring growth is correlated much more closely to CO2 than to temperature.

    Finally, it must be repeated that the planet is emerging from the Little Ice Age along the same trend line. There has been no acceleration of the very *mild* upward trend, despite a 40% increase in [harmless, beneficial] CO2.

    Conclusion: CO2 has little if any effect on temperature, and the demonization of “carbon” is simply a nefarious ploy to extract more taxes from the populace based on a thoroughly debunked belief system.

  169. Smokey says:
    November 18, 2011 at 6:38 pm

    These particular IPCC reports are based upon certain papers, and those papers rely upon assumptions and conclusions based upon imaginary data substituted for absent observations of proxy temperatures. It is another example of circular citations vouching for each other using reconstruction modeling lacking key empirical observations. You can be confident to a sigma 5 level that Kevin MacDonald can neither undeerstand or acknowledge the fallacies in his claimed sources of authority.

  170. Kevin MacDonald says:
    November 18, 2011 at 1:08 pm
    Yet [you’re] are unable to point to a period during the Holocene globally warmer than the current era.

    Again, you are evading the question. We are debating the question of whether or not your own examples are just such evidence. Your own sources indicate that every continent of the planet experienced HTM temperatures during the Holocene. It is now up to you to explain how it is possible for every continent to experience HTM temperatures in your source/s without them adding up to an average global temperature which is also HTM. Obviously, you can make a number of arguments about timing and other issues which have a potential for supporting your assertions, but we need to see you actually make those arguments and support them with the observational evidence. Otherwise, any claims about the global average temperature not being HTM is a claim lacking observational evidence. Fair warning: the sources you may choose to rely upon may be false and unreliable.

  171. Smokey and D. Patterson say:

    “Yet more irrelevant straw man fallacies about globally asychronous regional temperature variations”

    I’m paraphrasing, but you get the gist. None of Smokey’s links show a time where the Holocene showed globally sychronous temperatures as warm as current temperatures, unless you can provide this evidence you can’t argue that current global temperatures fall within the parameters of the Holocene.

  172. Kevin MacDonald is a textbook example of cognitive dissonance. I have literally thousands of charts, graphs and peer reviewed citations showing the various warming episodes during the Holocene. Temperatures have been gradually declining since the beginning of the Holocene. The charts and citations I’ve posted throughout this thread and others show that all regions of the planet experienced a MWP that was at least as warm as current temperatures, and most probably warmer.

    Prior global warming episodes were certainly even warmer than the MWP. No credible scientist disputes that fact. During those warmer events, CO2 remained quite low, negating the belief that CO2 causes global warming. It may cause minuscule added warmth, but the amount is insignificant and can be completely disregarded for all practical purposes.

    But someone afflicted with cognitive dissonance cannot agree with even one of the many charts and graphs I’ve posted, as Kevin MacDonald’s comment above demonstrates. If he agreed with even one chart, his carefully constructed belief system would come crashing down, causing him extreme discomfort and disharmony. That must be avoided at all cost, therefore, Kevin has no choice in the matter. He simply must reject out of hand any and all facts which contradict his catastrophic global warming belief system.

    Fortunately, scientific skeptics are largely immune from cognitive dissonance because we are just saying, “Prove it.” Provide solid empirical evidence that CO2 will cause runaway global warming and climate disruption. But there is no such evidence. None at all. There are only always-inaccurate computer models, which the real world is falsifying.

  173. Kevin MacDonald says:
    November 19, 2011 at 10:47 am
    Smokey and D. Patterson say:

    “Yet more irrelevant straw man fallacies about globally asychronous regional temperature variations”

    I’m paraphrasing, but you get the gist. None of Smokey’s links show a time where the Holocene showed globally sychronous temperatures as warm as current temperatures, unless you can provide this evidence you can’t argue that current global temperatures fall within the parameters of the Holocene.

    We do “get the gist” of the false arguments you copied from the Grist. We also see how your own source citations from AR3 confirmed the Early and Mid-Holocene generally had HTM global temperatures and as synchronous as any set of average global temperatures ever can be. When you then tried to use the interpretative statements in AR4 to deny a synchronous global average temperature in direct contradiction to the evidence in its own data sources, we offered you every opportunity to defend those false interpreations. Since you refuse to be responsive to the questions regarding the apparent invalidity of the AR4 interpretive statements regarding the Holocene temperatures, we can only conclude you must be avoiding the need to acknowledge that you are incapable of defending the false statements made in AR4 and by you. Nonetheless, you can take this one last chance to defend those false statements, before we perforce must conclude you are only trolling and propagandizing this blog with no genuine intent to engage in a genuine sientific debate.

    Your own data sources indicate HTM temperatures in their datasets for each of the continents. Each of these datasets has a certain amount of temporal overlap within the Holocene time period, which varies according to your cited authorities versus other authorities. Depending on the source/s used and their reported time periods for the datasets, most or all of the validated datasets indicate periods in the Holocene when the HTM were likely to be globally synchronous. In other words, your own cited sources, despite interpretive comments to the contrary, tend to indicate in each of the data sources that the Early Holocene to Mid-Holocene generally experienced HTM temperatures, and those HTM temperatures were often nearly globally synchronous or fully globall synchronous for periods of hundreds to thousands of years.

    You are free to attempt to show the readers which coring datasets provided by your sources demonstrate a failure to reach HTM temperatures in its region and in the resulting synchronous global average. You won’t, of course, because you cannot. What you do not want the readers to learn is the failure of your sources to actually make an observation of the temperatures for some of critical the regions they used in compiling the fabricated global average you are referencing in AR4. Before you attempt to deny or simply ignore this information, show us what your sources have to say about the Early Holocene and Mid-Holocene SST for Marsden Square 317. Otherwise, you’ll be dismissed as just another drive by troller looking to disrupt a blog, rather than engage in an honest scientific debate.

    Naturally, if you cannot or will not supply the Early to Mid-Holocene SST reported by your sources for Marsden Square 317, you would have absolutely no means of knowing the SST was low enough to make the global average temperature not HTM temperatures.

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