Guest post by Dr. Don J. Easterbrook
1934 has long been considered the warmest year of the past century. A decade ago, the closest challenger appeared to be 1998, a super-el nino year, but it trailed 1934 by 0.54°C (0.97°F). Since then, NASA GISS has “adjusted” the U.S. data for 1934 downward and 1998 upward (see December 25, 2010 post by Ira Glickstein) in an attempt to make 1998 warmer than 1934 and seemingly erased the original rather large lead of 1934 over 1998. The last phases of the strong 2009-2010 el nino in early 2010 made this year another possible contender for the warmest year of the century. However, December 2010 has been one of the coldest Decembers in a century in many parts of the world, so 2010 probably won’t be warmer than 1998. But does it really matter? Regardless of which year wins the temperature adjustment battle, how significant will that be? To answer that question, we need to look at a much longer time frame‒centuries and millennia.
One of the best ways to look at long-term temperatures is with isotope data from the GISP2 Greenland ice core, from which temperatures for thousands of years can be determined. The ice core isotope data were obtained by Minze Stuiver and Peter Grootes from nuclear accelerator measurements of thousands of oxygen isotope ratios (16O/18O), which are a measure of paleo-temperatures at the time snow fell that was later converted to glacial ice. The age of such temperatures can be accurately measured from annual layers of accumulation of rock debris marking each summer’s melting of ice and concentration of rock debris on the glacier.
The past century
Two episodes of global warming and two episodes of global cooling occurred during the past century:
1880 to 1915 cool period. Atmospheric temperature measurements, glacier fluctuations, and oxygen isotope data from Greenland ice cores all record a cool period from about 1880 to about 1915. Many cold temperature records in North America were set during this period. Glaciers advanced, some nearly to terminal positions reached during the Little Ice Age about 400 years ago. During this period, global temperatures were about 0.9 ° C (1.6 ° F) cooler than at present. From 1880 to 1890, temperatures dropped 0.35 ° C (0.6° F) in only 10 years. The 1880 –1915 cool period shows up well in the oxygen isotope curve of the Greenland Ice Sheet.
1915 to 1945 warm period. Global temperatures rose steadily in the 1920s, 1930s, and early 1940s. By the mid-1940s, global temperatures were about 0.5 °C (0.9° F) warmer than they had been at the turn of the century. More high temperature records for the century were recorded in the 1930s than in any other decade of the 20th century. Glaciers during this warm period retreated, temperatures in the 1930s in Greenland were warmer than at present, and rates of warming were higher (warming 4°C (7° F) in two decades). All of this occurred before CO2 emissions began to soar after 1945, so at least half of the warming of the past century cannot have been caused by manmade CO2.
1945 to 1977 cool period. Global temperatures began to cool in the mid–1940’s at the point when CO2 emissions began to soar. Global temperatures in the Northern Hemisphere dropped about 0.5° C (0.9° F) from the mid-1940s until 1977 and temperatures globally cooled about 0.2° C (0.4° F). Many of the world’s glaciers advanced during this time and recovered a good deal of the ice lost during the 1915–1945 warm period. Many examples of glacial recession cited in the news media show contrasting terminal positions beginning with the maximum extent at the end of the 1880-1915 year cool period and ending with the minimum extent of the recent 20 year warm period (1977-1998). A much better gauge of the effect of climate on glaciers would be to compare glacier terminal positions between the ends of successive cool periods or the ends of successive warm periods.
1977 to 1998 global warming The global cooling that prevailed from ~1945 to 1977 ended abruptly in 1977 when the Pacific Ocean shifted from its cool mode to its warm mode in a single year and global temperatures began to rise, initiating two decades of global warming. This sudden reversal of climate in 1977 has been called the “Great Pacific Climate Shift” because it happened so abruptly. During this warm period, alpine glaciers retreated, Arctic sea ice diminished, melting of the Greenland Ice Sheet occur.
The abruptness of the shift in Pacific sea surface temperatures and corresponding change from global cooling to global warming in 1977 is highly significant and strongly suggests a cause-and-effect relationship. The rise of atmospheric CO2, which accelerated after 1945 shows no sudden change that could account for the “Great Pacific Climate Shift”.
1999 to 2010 global cooling. No global warming has occurred above the 1998 level and temperatures have declined slightly.
The past 500 years
Temperature oscillations recorded in Greenland ice cores over the past 500 years (Fig. 2) are truly remarkable. At least 40 periods of warming and cooling have occurred since 1480 AD, all well before CO2 emissions could have been a factor.
The past 5,000 years
Figure 3 shows oxygen isotope ratios from the GISP2 Greenland ice core for the past 5,000 years. Note that temperatures were significantly warmer than present from 1500 to 5000 years ago.
The past 10,000 years
Most of the past 10,000 have been warmer than the present. Figure 4 shows temperatures from the GISP2 Greenland ice core. With the exception of a brief cool period about 8,200 years ago, the entire period from 1,500 to 10,500 years ago was significantly warmer than present.
Another graph of temperatures from the Greenland ice core for the past 10,000 years is shown in Figure 5. It shows essentially the same temperatures as Cuffy and Clow (1997) but with somewhat greater detail. What both of these temperature curves show is that virtually all of the past 10,000 years has been warmer than the present.
So where do the 1934/1998/2010 warm years rank in the long-term list of warm years? Of the past 10,500 years, 9,100 were warmer than 1934/1998/2010. Thus, regardless of which year ( 1934, 1998, or 2010) turns out to be the warmest of the past century, that year will rank number 9,099 in the long-term list.
The climate has been warming slowly since the Little Ice Age (Fig. 5), but it has quite a ways to go yet before reaching the temperature levels that persisted for nearly all of the past 10,500 years.
It’s really much to do about nothing.
That explains why there were forests in the far north of Canada back 5000 years ago.
Henry-
I referred to the IPCC report because it represents the latest global consensus on climate modeling and CO2..
But each year the United States two major modeling labs, GISS and NCAR also publish 10s of papers in both popular and technical scientific journals describing their approaches to climate modeling, including the impact of CO2. GISS 2010 publications are available here: http://pubs.giss.nasa.gov/abstracts/2010/
One of the latest from GISS is “Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature” in the 10/15 issue of Science, which can be found at: http://pubs.giss.nasa.gov/docs/2010/2010_Lacis_etal.pdf
This article supplies or links the information you claim to want, but claim you are unable to find, including this summary: “Of the 2.9 W/m2 of GHG radiative
forcing from 1750 to 2000, CO2 contributed 1.5 W/m2, methane 0.55 W/m2, and CFCs 0.3 W/m2, with the rest coming from N2O and ozone (15). All of these increases in noncondensing GHG forcing are attributable to human activity.”
But I suspect that is still not enough for you.
Ray,
Correct observation. The planet has been warmer many times during the Holocene, as tree lines all over the globe show. The current *mild* warming is indistinguishable from those numerous prior warmings.
All the emotional hand-wringing over what is clearly natural climate variability sends some members of the CAGW Doomsday Cult over the edge.
The only verifiable effect of the increase in harmless, beneficial CO2 is increased agricultural productivity. There is no evidence of global harm due to the ≈40% increase in that minor trace gas.
A 40% increase is not insignificant. You would think that there would be some major evidence of global harm as a result. The fact that there is no such verifiable, testable evidence is a strong indication that CO2 is harmless. But some folks are fixated, and they just can’t let go of their repeatedly falsified conjecture.
Smokey says:
December 30, 2010 at 3:05 pm
“Natural climate variability completely explains the rise, with no need for an extraneous variable such as CO2 — which follows rises in temperature. Effect cannot precede cause, and the climate null hypothesis has never been falsified. What we are observing is natural and routine.”
Totally. 100% agree with you, and that point could be made with the provided graphs, and I think Dr. Easterbrook has made an excellent contribution to this, particularly the importance of cool/warm phases in the big climate change picture. See here for that:
http://scienceandpublicpolicy.org/images/stories/papers/reprint/multidecadal_tendencies.pdf
But that’s NOT so in the article this a thread for. Dr. Easterbrook was making comparisons about 2010, while none of the graphs even show the last decade. And as far as Figure 5, the critiques are valid. Dr. Easterbrook very clearly made the statement: “So where do the 1934/1998/2010 warm years rank in the long-term list of warm years? [ referring to Fig. 5 graph!] Of the past 10,500 years, 9,100 were warmer than 1934/1998/2010. [–> FALSE, they were warmer than 1905; check the graph] Thus, regardless of which year ( 1934, 1998, or 2010) turns out to be the warmest of the past century, that year will rank number 9,099 in the long-term list.” [–> false statement].
Pointing this out does NOT make one a “Pro-AGWer”, “alarmist” or what not.
Henry-
An example of an NCAR publication which supplies the information or links you claim to want is the the 4/16/2010 issue of Science, “Tracking Earth’s Energy”, and available here: http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/T_SciencePerspectiveApril10.pdf
It contains the information you claim to be unable to find, including this summary: “Increasing concentrations of carbon dioxide (CO2) and other greenhouse gases have led to a post-2000 imbalance at the top of the atmosphere of 0.9 ± 0.5 W m–2 ( 5); it is this imbalance that produces “global warming.””
Additional supporting information is available here: http://www.cgd.ucar.edu/cas/Trenberth/trenberth-publish.html#2010
But I suspect that is still not enough for you.
I remember walking to school in the fall/winter of 1948 and gathering ice off the tops of the cars and making ice-ball to throw at the other kids. This was in Santa Monica, California, about 1 1/2 miles from the Pacific Ocean…….
I’m pretty sure is was that New Years Day parade in Pasadena, that a neighbor girl rode on one of the floats – in a bathing suit – and thought she would freeze to death before it was over!
Found this Online:
“I have a picture of the snowfall (in Pasadena) taken January 1949.”
I guess all those war-time factories had stopped producing C02, so things cooled off.
Oregon P says:
“Of the 2.9 W/m2 of GHG radiative forcing from 1750 to 2000, CO2 contributed 1.5 W/m2, methane 0.55 W/m2, and CFCs 0.3 W/m2, with the rest coming from N2O and ozone (15). All of these increases in noncondensing GHG forcing are attributable to human activity.
But I suspect that is still not enough for you.”
It seems you know why I would not be satisfied? yes, those are the results. But I wanted to know how the experiments were done to get to these results.
The reality I had to consider, is: there are no such results from any such experiments, that gave those measurements, other than the one experiment called ‘planet earth”..
So it is a dudd. From AS to IPPC 2007. The horse is behind the carriage, everywhere.
So my question started with: what if there is nothing wrong with CO2 and my carbon footprint? What if modern warming is not caused by GhG’s?
and that is why I am now here:
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
Here in South Africa we are now just a few hours away from 2011 so I don’t think I will be back here with you again in 2010
Have a wonderful 2011 you all!
may God be with us all, this 2011
(especially those that believe in honesty and truth)
Oregon Perspective says:
December 31, 2010 at 10:49 am
Henry-
I referred to the IPCC report because it represents the latest global consensus on climate modeling and CO2..
You seem to have some difficulty coming to grips with the concept of “evidence”. Even the creators of all those GCMs freely admit that they are all almost completely inadequate at modeling any part of the role of H2O in the planet’s climate. H2O in its myriad aspects, impacts and influences is, as the primary mediator of the energy that the Sun provides to the Earth, responsible for almost everything that constitutes what we speak of when discussing the weather and climate, including the dubious positive feedbacks which are at the core of the catastrophic projections of the CAGW hypothesis. Until the GCMs model H2O with much more thoroughness than they presently provide for CO2, which despite decades of effort and billions invested is in itself nothing to brag about, running endless iterations of them from now to the next millennium may suggest some new questions to pursue, but will never provide a substantial answer to any of the questions which have already been asked.
Ray and Peru-
Smokey, Henry, Bill, and even Easterbrook are is just [snip] you on this. They are saying that hundreds of climate research scientists, who have published their methods, data, and analysis in 1000s of research articles are wrong. But Smokey, Henry, Bill, and Easterbrook, who have done none of that, are right. They’re not.
The giveaway is in the first sentence of Easterbrook’s article, which begins “1934 has long been considered the warmest year of the past century.” Easterbrook is either [snip ~ ad hom]. 1934 was only one of the warmest years of the past century in the United States. 1934 was not a warm year around the world. You can see that difference in figures 1 and 4 at http://data.giss.nasa.gov/gistemp/2007/
[Really? – try this: http://wattsupwiththat.com/2010/09/04/in-search-of-cooling-trends/ it uses GISS data too, and compare it with the figure labelled (b) on the GISS page]
So Easterbrook either, unknowlingly cherry-picked his data, or [snip]. That’s propaganda, not science.
The same is true of his use of the GISP2 data. Easterbrook, Smokey, and Bill pretend that the Greenland ice core temperatures are representative of global temperatures. Even Alley, who gathered that data says they are not. Again, [snip].
I don’t think this individuals are interested in testing their ideas against the evidence, which is what science does. They are merely cherry-picking or misrepresenting evidence to make their ideas (whereever they come from) seem respectable, without publishing them where knowledgeable peers can respond.
[Professor Easterbrook knows what publication requires: here is his publications list.]
Neither Easterbrook’s first sentence nor his paper would survive peer-review. Not because of a conspiracy of climate research scientists. But because some people care about honestly testing ideas against evidence, and other people don’t.
GISS and NCAR have 100s of publications with methods, data, and analysis to back up there conclusions. This bunch doesn’t.
It doesn’t usually take long to figure out who your talking to.
[And your grammar would not survive peer-review in fourth grade. On the other hand read this posting, which hardly commends peer review.
Note – your comment above has been languishing in the spam queue. Continued postings in this vein are likely to earn similar treatment. Commenters here are expected to adhere to the blog policy (under About WUWT tab at top) about Ad Hominem and to add to the discussion, not just rubbish the guest author’s and other commenters’ opinions ~jove, mod]
[Reply from another moderator: Dr Easterbrook is well respected professionally, and has generously offered to write this article. Having read your comments that were snipped by moderator jove, please take this as a warning. Further vicious personal attacks like the ones snipped will result in your future posts being sent straight to the spam bucket. ~dbs, mod.]
Dr. Easterbrook,
Thanks for a great post.
Have you ever studied the volcanic activity – relative to the warming – cooling, over the past 10,000years?
As a design professional, attempting to use the best possible information in my practice, I am deeply appreciative of your efforts.
I have been pleased (so far) with my ‘overgain’ passive solar designs.
I design in ‘overgain’ to force natural ventilation – if global cooling becomes an issue – these structures will no longer be quite so independent of the back-up heating systems.
I will continue my study.
Have a great new year!
Not Another Architect
Someone reminded me recently that I used to point out we were far below the 10,000-year average, so wake me up when we get *that* high… and this was back in the late 1990s.
I wish I knew where I’d got that data, though I did a big research project on the subject about 1998, I don’t have the source for that factoid handy.
My only point was that the general fact of where we lie in the long term has been known (and ignored by CAGW boosters) for quite a long time. I got it from someone else’s research, I didn’t come up with those facts on my own.
So many people have made CAGW a career, however, that even if it’s debunked it will be like ending the income tax – most the accountants and the IRS would be out of work, so they fight like heck against the very idea.
Henry@oregon P
You now resort to name calling because you feel threathened.
I am guessing here that your livelyhood depends on the lies about global warming being true. I do understand that you are angry. Unfortunately I cannot change the truth. It is all here. All the facts.
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
The average temps. we have today is still lower than the average temperature of the last 10000 years during which most of humanity developed.
Our (religious) forefathers tried to stop the truth from spreading, that the earth was a round ball and not in the centre of the universe. In the end they did not succeed. ..
they forgot that Jesus (God) is the truth. The truth does have this habit of making an appearance every so often. Better be prepared for that. Look for another job while you still can?
If you do not accept my findings, bring your arguments.
Otherwise those here who know the truth are simply going to shrug and say: there are none so blind as those who do not want to see…..
Reading the sceptics of climate science is like reading the sceptics of evolution for me, a non-scientist. Ya’ll are nitpicking to find any little thing to scream “discrepancy” and ignoring the larger picture. In the case of evolution, the larger picture is “what can we learn about human nature and how can we use that to improve our condition?” In the case of climate science, it is “how have we humans impacted our environment and what can we do to lessen the impact or turn it into a neutral or positive rather than a harmful effect?” It doesn’t seem to me (again, I am a non-scientist) that the effluents we have been spewing into our atmosphere, oceans, and land for the last 150 years especially, are particularly benign whether they result in overall warming or not. The point is to clean up our act, not to split hairs over data that may or may not be ambiguous. If you LIKE breathing smog or absorbing radiation or ingesting toxic chemicals, fine. If you make money off of activities that result in these ill effects, your bias is noted. However, the rest of us have a vested interest in our own and the planet’s continued good health and survival. So nitpick all you want, the vast majority of us want the industrialized world to clean up our act and the time to begin it is a couple or five decades ago, or at the latest, NOW, but not “never.”
henry@p-moment
It appears you missed the point that CO2 is not a pollutant.
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
Everything you ate and drank today (except if it were pure water)
depends on carbon dioxide.
We need more of that, not less.
You can filter out all other evils
(CO,SO2, heavy metals)
but please put more CO2 in the air
not less.
Milankovitch clearly explained that 10,000 year until now shows a decrease in Northern Hemisphere summer irradiance. Greenland thus received significantly more solar energy in the summer than it does not. It’s actually surprising that the reduction in solar irradiance over the past 10,000 years did not cause more cooling. Now that the Arctic is warming up 4 C in the past couple of decades, after cooling according to Milankocitch cycles for a few degrees over 10,000 years, it is clear that something truely profoundly different is diving the recent warming in the Arctic.
Henry@Rob
It appears to me that the entire Holocene — the period over which, by some odd coincidence, humanity developed agriculture and civilization — the temperature has been higher than now, and the trend over the past 4000 years is a marked decline. From this perspective, it’s the LIA that was unusual, and the current warming trend simply represents a return to the mean.
Perhaps do some real research yourself?
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
However I agree with the premise of this article, I think the years at the bottom of these charts aren’t right, you can’t assume that ice core rings are annual rings.
[youtube=http://www.youtube.com/watch?v=ue8rVSmrmZ0&fs=1&hl=en_US]
Henry@elmer
They must have worked out some calibration method
e.g. the last graph in the article clearly shows the Roman warm period,
at the correct year hundred
which was known in England,
it was why the Romans could conquer England
If the rings are not years, then what do they represent?
And now using the data missing in the mutilated graph (the last 100 years that show a warming of 3ºC), temperatures in Greenland now are 2ºC warmer than in the Medieval Warm Period and 1ºC warmer than in the Roman Warm Period, and tied with the temperatures in the Minoan Warm Period and the Holocene Maximum.
That is, temperatures unprecedented (in Greenland) in the last 3400 years!
This is a point that is missing in the Dr. Don J. Easterbrook post.
Now I make this question again (nobody has even tried to answer it, someone just denied* that there has been 3ºC of warming in Greenland, showing that he cannot tell the difference between regional and global warming):
(NOTE: when I used the verb “denied*”, I do NOT call “denier” someone, only decribe what has been doing in his comments, that is negating the evidence.)
Why has Greenland warmed to levels near those seen in the most warm periods in the Holocene, given that Milanktovich Cycles has been in a cooling trend for millenia?
@Henry P & Merovign
Care to actually put a figure on what you think the average global temperature of the last 10k years is and how you derived it? So we can, you know, check your working, compare it to today and see if your claim stands up?
The irrational nonsense that is perpetuated on this site is alarming. It has already been noted in various comments that 1934 is not one of the warmest years on record globally. Confusing USA with the globe is an ignorant mistake. At least make a correction when it is pointed out. Just as the USA is not the world, neither is Greenland. And why do you perpetuate the bogus contention that the globe has cooled since 1998? This past decade was the warmest in the instrumental record. Every global temperature record shows a warming trend since 1998. For those of you who are confused, no climate scientist predicts a monotonic warming inline with CO2 increase. You are cherry picking data and arguing with straw men. Stop it and get back to reality!
bgood2creation says:
January 2, 2011 at 2:37 pm
“The irrational nonsense that is perpetuated on this site is alarming. (…) And why do you perpetuate the bogus contention that the globe has cooled since 1998? This past decade was the warmest in the instrumental record. Every global temperature record shows a warming trend since 1998. For those of you who are confused, no climate scientist predicts a monotonic warming inline with CO2 increase. You are cherry picking data and arguing with straw men. Stop it and get back to reality!”
Well said!
It seems that some people simply can’t (or more precisely, doesn’t want to) undestand this facts!
bgood2creation says:
“You are cherry picking data and arguing with straw men.”
If picking 1998 is cherry-picking [which I agree it is], then to avoid that problem we should look at various, and longer, time frames. [Incidentally, picking “the instrumental record” is no different than cherry-picking 1998.]
My preference is the Holocene, which is generally accepted as the beginning of the current interglacial. It covers the past ≈10,000 years, and so avoids picking one particular year, or even a few decades.
Also, I agree that Greenland is a specific region. So to make the discussion global, we will add the Antarctic. The Vostok ice cores correlate well with GISP-2 in Greenland [as do other ice core locations], so we can be reasonably certain that unusually warm or cold periods like the MWP and the LIA were global events.
Looking at a chart of Greenland’s temperatures during the Holocene, we see that it was considerably warmer than up to a century and a half ago, when the ice core record stops due to the fact that annual snow cover has not yet compacted into ice.
Keep in mind that the temperature rise over the past ±150 years is widely accepted to be ≈0.7°C. That shows us that Greenland has been significantly warmer than today during much of the Holocene.
Likewise, temperatures in the Southern Hemisphere [at Vostok in Antarctica] have been much warmer than now many times throughout the Holocene.
In addition, there is physical evidence showing that rises in CO2 follow rises in temperature. There appears to be an ≈800 year lag between temperature rises and CO2 rises at millennial time scales. That would attribute much of the curent CO2 rise to the MWP.
And although increased CO2 will cause some minor global warming, it must be kept in mind that the past century’s 0.7°C rise was caused at least in part by the planet’s emergence from the LIA. It is baseless conjecture to attribute 100% of that relatively insignificant rise entirely to CO2. And there is no doubt that more CO2 has resulted in increased agricultural yields; more CO2 is clearly beneficial to the biosphere.
Further, the IPCC’s own figures show that the anthropogenic portion of CO2 emissions is dwarfed by the planet’s natural emissions.
Next, the climate’s sensitivity to CO2 must be a small number, very likely less than 1°C per doubling. If the sensitivity number were large [eg: the IPCC’s preposterous 3 – 6°C], then the temperature would closely track changes in CO2. This is obviously not the case. There is little correlation between temperature and CO2 at short time scales, therefore climate sensitivity to CO2 must be small. QED
So we see a few things in these graphs. First, we are in an interglacial period, where global temperatures have routinely been much higher than they are now. We see that the normal condition of the planet is glacial. We see that natural variability fully explains the current climate, with no necessity for a minor extraneous variable such as CO2. We see that during the Holocene temperatures have been much higher than today’s pleasant climate. And by adding the 0.7°C warming since the Industrial Revolution onto the GISP-2 evidence, we see that temperatures of 2 – 3°C higher than curent were commonplace; the claim that current temperatures were anywhere near the Minoan Optimum are baseless nonsense.
Therefore, your statement that “The irrational nonsense that is perpetuated on this site is alarming” is falsified. The facts that have been presented in these graphs are neither irrational, nor are they nonsense.
The question that must be answered by the alarmist crowd is this: what empirical, testable evidence shows that actual global harm has resulted from the [not-insignificant] ≈40% rise in CO2? With such a large increase, if CO2 were harmful, there would already be noticeable damage to the planet.
Yet there is no such evidence.
The conclusion: CO2 is both harmless and beneficial at these levels. The CO2=CAGW scare is debunked, and all the references to “carbon”, “carbon footprint”, “carbon credits”, and so on, are based on pseudo-science, and on the refusal to adhere to the scientific method.
Cold kills. Warmth is good. And more CO2 is beneficial.
Henry@Smokey
I could not have said it any better! God bless you!
Henry@those who do not want to hear the truth:
What Smokey just said here on this site would simply have been wiped at any pro-AGW site. I know. I have been there, done that. They just did not give me the T-shirt.
So if you find the irrational nonsense perpetuated on this site alarming, why don’t you go back there? Any type of story will be allowed there, as long as it supports the argument that man made carbon dioxide is evil. Unfortunately it will change nothing to the truth. I hope you realize that?
http://www.letterdash.com/HenryP/more-carbon-dioxide-is-ok-ok
Smokey says:
January 2, 2011 at 6:21 pm
“Keep in mind that the temperature rise over the past ±150 years is widely accepted to be ≈0.7°C.”
You are again confusing GLOBAL temperatures (that have indeed warmed 0.7ºC) with REGIONAL temperatures in Greenland, that have warmed between 2ºC and 4ºC. It is so difficult to understand?
“That shows us that Greenland has been significantly warmer than today during much of the Holocene”
This is quite false, now we are at temperatures as high as in the Minoan Warm Period and the Holocene Maximum in GREENLAND.
“And by adding the 0.7°C warming since the Industrial Revolution onto the GISP-2 evidence, we see that temperatures of 2 – 3°C higher than curent were commonplace; the claim that current temperatures were anywhere near the Minoan Optimum are baseless nonsense”
What is nonsense is comparing the GLOBAL temperatures with the REGIONAL paleoclimate data in GREENLAND. You are comparing apples with oranges. The temperatures in Greenland are near the temperatures of the Minoan Warm Period (or even warmer).
“In addition, there is physical evidence showing that rises in CO2 follow rises in temperature. There appears to be an ≈800 year lag between temperature rises and CO2 rises at millennial time scales.”
That is a positive, amplyifing feedfack. What it shows is that warming (that in the past was caused by Milanktovich Cycles) liberates CO2 from the ocean. This in turn generates more warming. This is one of the mechanisms that explains why the mild forcing from Milancktovich cycles can drive the planet from ice ages to interglacials and viceversa.
“That would attribute much of the curent CO2 rise to the MWP”
This is total nonsense. The current rise, equal to the difference between glacial and interglacial periods, cannot be explained by the small warming of the MWP. The oceans now are net absorbers, not emitters, of CO2; as a result, the ocean acidity has increased by 30%. If the ocean warming were the cause of the rise of CO2 , the acidity would have dropped, not increased. Obviously this monstruous rise in CO2 is caused by the emission of CO2 from fossil fuel burning, that is ocurring at a rate not seen in billions of years.
“The question that must be answered by the alarmist crowd is this: what empirical, testable evidence shows that actual global harm has resulted from the [not-insignificant] ≈40% rise in CO2? With such a large increase, if CO2 were harmful, there would already be noticeable damage to the planet.
Yet there is no such evidence. ”
Have you read the extensive literature about the alarming events that are happening right now in the planet?
Are you aware that summertime Arctic sea ice volume has dropped by 80%?
http://psc.apl.washington.edu/ArcticSeaiceVolume/images/BPIOMASIceVolumeAnomalyCurrent.png
What about the accelerating meltdown of the Greenland and Antarctic ice sheets, 100 years ahead of what climate models predicted?
“Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE”
http://thingsbreak.files.wordpress.com/2009/10/increasing-rates-of-ice-mass-loss-from-the-greenland-and-antarctic-ice-sheets-revealed-by-grace.pdf
And the rate of sea level rise, that is at the top of the range predicted by the IPCC?
And much more. A good review is here:
http://www.ccrc.unsw.edu.au/Copenhagen/Copenhagen_Diagnosis_LOW.pdf