NAS reports: 50 million year cooling trend

Warming in a global cool period

By Peter N. Spotts| Staff Writer for The Christian Science Monitor/ September 25, 2008 edition


Graph above added by Anthony – not part of original article

With all the focus on human-triggered global warming, it may be hard to imagine that the world is riding a 50-million-year-long cooling trend.

But it is, and blame the trend on a continental-scale collision, say geophysicists Dennis Kent of Rutgers University and Giovanni Muttoni of the University of Milan in Italy.

Researchers say there is strong evidence that increases in atmospheric CO2 contributed to a warm spell 50 million years ago dubbed the Early Eocene climate optimum – the warmest period in 65 million years. But over the following 15 million years, deep sea temperatures fell by about 10.8 degrees F., reflecting a significant cooling at the surface. This cooling ultimately allowed the cycle of ice ages to emerge.

Drs. Kent and Muttoni have mined paleomagnetic and other data and suggest that atmospheric CO2 dropped because India collided with Eurasia, shutting down a productive, natural CO2 factory.

Some 120 million years ago, the subcontinent that is now India was migrating north from Antarctica. As it moved, it shoved the ocean crust that was ahead of it under an existing crustal plate. As long as this zone off the Eurasian coast was under water, bottom muck enriched by carbon from the biologically-rich ocean plunged under the plate. It got recycled as lava in volcanoes along a geological feature dubbed the Kohistan Arc, as well as in a vast lava-oozing formation called the Deccan Traps. The eruptions released the carbon as CO2, which helped warm the climate. But once India collided with Eurasia 50 million years ago, India rode over the top of the zone and shut off the process. This, plus changes in ocean circulation as continents rearranged themselves, contributed to the long chill, the researchers suggest.

The results appear in the current issue of the Proceedings of the National Academy of Sciences.

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118 Responses to NAS reports: 50 million year cooling trend

  1. Alan B says:

    I have not read the article concerned but there is another option for the loss of CO2. When India ploughed into Asia the himalayan range and the Tibetan plateau were formed. This major mountain building episode was follwed by rapid erosion. Indeed, erosion and uplift are still actively working in the area.

    The theory is that CO2 is involved in the weathering of silicate rocks. The CO2 is incorporated into ocean sediments as carbonates, thereby removing it from the atmosphere. The same effect does not occur with carbonate rocks.

    for example, see
    American Journal of Science, Vol. 301, February 2001, pp 182-204
    Berner & Kothavala

  2. Jeff says:

    Even if Global warming is happening, I believe it would be a good thing for all parts of the earth (exept the populated parts that would be submerged in water; I guess they would need to build dikes).

  3. SteveSadlov says:

    CO2 has been in a general decline over the entirety of geological history. Sure there have been a few attempted renewals, but the long term trend is what it is. It’s disturbing. There may be deadly changes to the Earth’s ability to sustain life, well prior to those owing solely to the life cycle of the Sun.

  4. John-X says:

    I remember the Eocene and it was an awful lot warmer back then.

    You kids complaining about “warming” today don’t know how good you got it.

    You got air conditioning. We didn’t even have ice.

    Bu then, we also didn’t have people like Gore and Hansen telling us how rotten we were.

  5. Phillip Bratby says:

    I thought this type of information about CO2 was fairly standard in geology text books.

  6. sonicfrog says:

    But again, doesn’t the drop in temp levels lag by several thousand years behind the drop in CO2 during this period?

  7. Bill Illis says:

    I always say that the position of the continents and continental drift has a big effect on Earth’s average temperature.

    Move North America 200 miles south and there would have been no North American ice ages. The (cooler) summers of the past due to Milakovitch cycles would still have melted all the snow on land over the summer and there would not have been glaciers.

    600 million years ago and 300 million years ago, most of the southern continents were locked together over the south pole. Glaciers build up at the poles, move north, spread out over the land and pretty soon all of the near-by land is covered in glaciers. Think Antarctica times ten. We had snow-ball Earth and a long ice age period.

    We do know that glaciers do not build up on the oceans. Sea ice freezes, but glaciers cannot spread out very far over the oceans.

    Whenever there is land over the poles, there are land-based glaciers and the Earth’s climate cools. The more the continents are weighted toward the poles, the colder Earth’s climate gets.

    Over the last 50 million years, North America, Greenland and Eurasia have all moved north due to continental drift. About 2.5 million years ago, they moved just far enough north that we became susceptible to Milakovitch cycles and periodic ice ages occurred.

    I don’t buy the Indian continental drift – Himalayan uplift argument since this has occurred throughout Earth’s history dozens of times without the same effects. Continents have always been moving around, moving over oceanic crustal plates and crashing into each other.

  8. T Bailey says:

    Interesting article, but a question still remains… how much does Carbon actually affect temperatures? Or, could it be that temps affect Carbon? What else was happening 50 million years ago that may have caused temperatures to go up with CO2 trailing behind it?

    But, of course, carbon must be the nemesis… so much so that Gore wants companies that don’t tow the green line to be investigated, for carbon to be taxed, and also to use carbon scare as an incitement to lawlessness. Guess he read the England / Hansen vandal case and got excited about the possibilities.

    Just think, get the riots started and then go in and sell his scam to fix the world’s ills.

    http://blog.wired.com/sterling/2008/09/al-gore-calls-f.html

  9. Richard deSousa says:

    What was the CO2 level at the time of the Eocene Optimum?

  10. Ray says:

    This is not the first time that I hear this idea that past volcanic eruptions released lots of CO2 in the atmosphere, followed by increase in global temperature and bla bla bla.

    They want you to believe that a volcano just pukes CO2. Well well well, there is also lots of SO2 being ejected in the atmosphere during a volcanic eruption. We know that SO2 has a major cooling effect. Moreover, how come every time there is a major volcanic eruption in our times, it is followed by a global cooling of the temperature? Has atmospheric chemistry changed so much between then and now?

  11. Gary says:

    To be fair, humans have been living in the cool period and at the warmer part of the range so changes from our current comfort level are disconcerting. That being said, there’s no reason to discount the massive natural forces that regulate the climate and in trying to figure out the variability and it’s causes.

    BTW, could you add a citation and some explanation of the details of the graph since it supplements the article? Thanks.

  12. Leon Brozyna says:

    Oh no – a new challenge – stop the continents from drifting!

    O/T – Watts happened to WUWT viewership? According to Alexa & Quantcast it’s down to 0!!

    http://www.alexa.com/data/details/traffic_details/wattsupwiththat.wordpress.com?site0=realclimate.org&site1=wattsupwiththat.wordpress.com&y=r&z=2&h=300&w=610&c=1&u%5B%5D=realclimate.org&u%5B%5D=wattsupwiththat.wordpress.com&x=2008-06-07T14%3A13%3A10.000Z&check=www.alexa.com&signature=4DQ6f7l6e6EWYI8FTiVhrxCq5Fo%3D&range=1m&size=Medium

    and

    http://www.quantcast.com/profile/traffic-compare?domain0=realclimate.org&domain1=wattsupwiththat.wordpress.com&domain2=&domain3=&domain4=

    REPLY: I think its either a glitch in reporting data or a side effect of the spam attack I had this weekend, meanwhile the WordPress internal traffic counter continues to register increasing traffic. – Anthony

  13. Jeff Alberts says:

    Did they look at ANYTHING besides CO2? Doesn’t seem so.

    Wouldn’t the same eruptions which released CO2 also release particulates which would cause cooling? And doesn’t such cooling always seem to overpower any other warming factors?

  14. Ric Werme says:

    Leon Brozyna (09:44:49) :

    O/T – Watts happened to WUWT viewership? According to Alexa & Quantcast it’s down to 0!!

    REPLY: I think its either a glitch in reporting data or a side effect of the spam attack I had this weekend, meanwhile the WordPress internal traffic counter continues to register increasing traffic. – Anthony

    It looks like there were some diddles to the IP addresses associated with the domain names:

    $ host wattsupwiththat.com
    wattsupwiththat.com has address 72.233.69.6
    wattsupwiththat.com has address 72.233.2.54
    wattsupwiththat.com has address 72.233.2.56

    $ host wattsupwiththat.wordpress.com
    wattsupwiththat.wordpress.com is an alias for lb.wordpress.com.
    lb.wordpress.com has address 76.74.255.123
    lb.wordpress.com has address 72.232.101.40
    lb.wordpress.com has address 72.232.101.42
    lb.wordpress.com has address 72.233.2.54
    lb.wordpress.com has address 72.233.2.56
    lb.wordpress.com has address 76.74.254.123

    If you check traffic for wattsupwiththat.com you’ll see data there.

    http://www.alexa.com/data/details/traffic_details/wattsupwiththat.com

    REPLY: Now it makes sense, WP support asked me to make a change to my config for domain mapping, and I did so this weekend. I suppose I could switch it back or just continue as is. – Anthony

  15. Joel Shore says:

    Ray says:

    They want you to believe that a volcano just pukes CO2. Well well well, there is also lots of SO2 being ejected in the atmosphere during a volcanic eruption. We know that SO2 has a major cooling effect. Moreover, how come every time there is a major volcanic eruption in our times, it is followed by a global cooling of the temperature? Has atmospheric chemistry changed so much between then and now?

    Jeff Alberts says:

    Wouldn’t the same eruptions which released CO2 also release particulates which would cause cooling? And doesn’t such cooling always seem to overpower any other warming factors?

    I think that the idea that the two of you are missing is that different processes can dominate on different timescales. A given major volcanic eruption releases lots of particulates and not all that much CO2. However, the particulates wash out of the atmosphere relatively quickly (generally within days when they are ejected only into the troposphere and within months to a few years when they are ejected into the stratosphere). CO2, by contrast, stays in the atmosphere a long time.

    Hence, if there is a general increase in volcanic activity, this can have a significant effect on determining the level of CO2 over the long term (even though the rise due to any individual eruption will be pretty negligible). However, unless the rate of volcanic activity is so large that you are getting huge eruptions (like Mt. Pinatubo) every several months to a few years, you will probably not affect the average level of particulates in the atmosphere that much.

  16. Steve Huntwork says:

    Was this a McCain joke? Sorry, but I could not stop laughing.

    John-X (08:55:18) :

    I remember the Eocene and it was an awful lot warmer back then.

  17. Suzanne Morstad says:

    This article is another example of “revisionist geology” where all temperature changes are presumed to be due to CO2 in spite of evidence to the contrary. According to multiple sources (e.g.Geocarb 3, Rothman, Kilmafakten) CO2 levels were higher than the time of the PET all through the the late Triassic, the icy times of the Jurassic and early Cretaceous and were close to PET levels of CO2 during the warmer late Cretaceous. Through out the geologic record there has been a poor correlation between CO2 and Sea surface temperatures. Also the Deccan Trap volcanism was active before the KT event 65mya and there was extensive sea floor spreading between Greenland and Europe 55mya with little effect on CO2 for almost 30million years with SSTs being both lower and higher than the PET.
    Except for in the world of climate models with their high sensitivity due to positive feedback from water vapor, CO2 appears to be very limited in its ability to cause significant warming with a ceiling imposed by saturation of the wavelengths absorbed by CO2 and the negative feedbacks from watervapor and clouds ( e.g. Hu, Christy and Spencer, Lindzen). In absence of a significant correlation between CO2 and temperature in the Geologic record and no non-modeled evidence for a strong amplifier of the modest warming effect of CO2, papers like this are pure speculation. (Unlike the Svensmark Hypothesis which was developed based on real world observations and is now being tested by the CLOUD project at CERN and by the drop in solar activity.)

  18. Patrick Henry says:

    Good thing the ocean no longer has muck or is biologically rich. Is this from the Eco-Enquirer? It can’t be a serious article.

  19. George Patch says:

    If CO2 is such a great warmer it should be something that could be duplicated in a lab. Has anyone built a tall enclosed aquarium and simulated the impact of various levels of CO2, water vapor and other elements of the atmosphere? I mean really, what was the amount of water vapor like 50 million years ago? How strong was the Sun? What about volcanic activity? Shouldn’t we look at the major sources of warming / cooling before jumping on the CO2 bandwagon?

  20. Gary Gulrud says:

    “atmospheric CO2 dropped because India collided with Eurasia, shutting down a productive, natural CO2 factory.”

    This is a bit counter-intuitive. The uplift of the Himalaya and Tien Xian (sp?) would have caused a major increase in erosive release of CO2. No doubt “there is a need for continuing research” resides somewhere in the paper.

  21. Dan Lee says:

    Finally, some perspective. An atmosphere that has remained stable enough to support the 3+ billion year evolution of life, through all these extremes, isn’t going suddenly spiral out-of-control into a life-baking oven when it hits 400 ppm of CO2.

    Yet another crack in the positive-reinforcement, CO2 tipping point argument.

    And that, as I understand it, is what the whole AGW edifice is based on.

    The positive feedback at the very core of the AGW case seems to be: CO2 warming enables more water vapor warming, which releases more CO2, which enables more wam-blanketing by water vapor, etc. in a positive feedback that spirals out of control after it reaches some tipping point.

    That’s why they had to get rid of the Medieval Warming Period, and other past climate optimums. Positive feedbacks weren’t triggered back then.

    That whole thing falls apart when either of the following are shown to be true:

    (1) there was more warmth in the past; (which didn’t trigger any positive feedback b/n CO2 and water vapor),

    (2) there was more CO2 in the past (which didn’t trigger any positive feedback either.)

    If you take away atmospheric positive feedback, aren’t we done? End of show? Nothing left for AGW to stand on?

    Are we giving them life by not shining the spotlight more on the core of their argument?

  22. Ric Werme says:

    Ray (09:35:31) :

    They want you to believe that a volcano just pukes CO2. Well well well, there is also lots of SO2 being ejected in the atmosphere during a volcanic eruption. We know that SO2 has a major cooling effect. Moreover, how come every time there is a major volcanic eruption in our times, it is followed by a global cooling of the temperature? Has atmospheric chemistry changed so much between then and now?

    Who are “they”? No geologist I know says volcanoes only puke CO2.

    Furthermore, SO2 only causes cooling if it reaches the stratosphere. A number of eruptions don’t emit enough SO2 or do so explosively enough to create the sulfate aerosol. The Deccan Trap eruptions were huge and non explosive as far as I know, and probably released a lot of SO2 that merely caused some severe acid rain. Perhaps you can find some good references for us.

    I don’t have data at my fingertips, but the Hawaiian volcanoes haven’t been linked to cooling, and the recent South American volcano wasn’t explosive enough. You really can’t beat a good exploding Indonesian eruption for a quick cooling, e.g. Tambora in 1815.

  23. Smokey says:

    Richard deSousa:

    “What was the CO2 level at the time of the Eocene Optimum?”

    It varied quite a bit, between about ~550 ppmv and ~1,500 ppmv. Here’s a chart that shows temp & CO2 levels: click

  24. Drew Latta says:

    O/T, but Re: Svensmark’s “The Chilling Stars”: for what it is worth, a recent astrophysical computer simulation that suggests that stars may migrate through the galaxy. The speculation might be that moving through the galaxy could change the flux of cosmic rays. See: http://news.nationalgeographic.com/news/2008/09/080918-star-migration.html

  25. G Alston says:

    Joel Shore — “CO2, by contrast, stays in the atmosphere a long time.”

    Really? How long? I’ve seen estimates that range from 10 years to 200 years, and these are from the alarmist crowd. The IPCC certainly doesn’t have a reliable and solid answer. There not only doesn’t appear to be a standard answer, implying that nobody knows *anything* about this that can be reliable, but the answers that come seem rather plastic. Depends on what the question was.

    I think I rather like the longer answer, because 200+ years suggests that what is in the atmosphere today, if attributable solely to mankind, is the cumulative output of man since the dawn of the industrial revolution. In that case, no big shakes. We can continue to drive all we like.

    Meanwhile those who downplay the longevity and stress shorter times point to the oceans as absorbers and emitters of the CO2. In which case, cool — CO2 seems to be emitted in the LIFO (last in first out) fashion, meaning that what’s being emitted today was (again) added from earlier times to the present emissions. (This results in the same answer as in the above paragraph, just in case you need assistance.)

    Seems to me that either answer gives the same result, so the contention that “CO2 lives a long time in the atmosphere” as an attempt to explain **anything** is specious at best.

    The truth is NOBODY knows how long CO2 stays in the atmosphere, and you, sir, sound like a parrot.

  26. Ray says:

    Well then… maybe all that SO2 created acid rain that killed a major portion of the vegetation. As we know, acid rain leeched soil takes a long time to regenerate and get plants growing again. Drive around Sudbury, Ontario and you will see what it looks like.

    The reduced vegetation will have the concentration of CO2 in the atmosphere rise. But then you have to admit that the absorption spectrum of CO2 gets saturated at relatively low level. On the other hand, less vegetation also means less water evaporation which could also turn to global cooling.

  27. DR says:

    They can’t reconstruct the last century or the MWP but 50 million years can be? Oh my, such vanity.

  28. Interesting observation, considering the earth is only 6012 years old according to venerated Archbishop James Ussher.

  29. Pieter F says:

    Another explanation of the early Cenozoic warming goes like this: following the KT-boundary event, a tremendous amount of methane was released in the putrefication of the biomass. Within the cooling caused by the atmospheric debris, the methane settled on the ocean surface to sink and become methanehydrates. As things got back to “normal,” the oceans warmed such that methane hydrates in the shallower area were released causing a higher than normal concentration of atmospheric methane and creating a super greenhouse effect.

    The onset of the Indian subcontinent colliding with Asia began around 50 mya causing the draining of the Tethys Sea (which, by the way, created condition that led to whales).

    The Tasman seaway deepened around the Middle and Late Eocene boundary (37.2 mya) allowing the first major flow from the Indian to Pacific Oceans. Just prior to that by about a million years, the onset of the Antarctic bottom water regime appears. The combination of those two led to a Late Eocene cooling. The Drake Passage is breached in the Late Oligocene creating a circum-Antarctic flow . . . and global cooling. Without going into much detail, other events that changed global climate dramatically include the Isthmus of Gibralter closing in the Late Miocene and the Isthmus of Panama closing in the early Late Pliocene.

    In 2005, I took Bila Haq’s sea level frequency data (with permission) and calibrated it to the Gradstein GTS (time scale) with Polar Ocean Equivalent temperature differences and notations on major geologic events. The geologic events correlate well with the sea level flux. It doesn’t appear to me that CO2 drove any of the changes. The methane story (as published in Nature a couple of years ago) is interesting.

  30. genuistim says:

    Great Posting – Very Interesting – and as always great comments to go around

  31. Yup. What I’ve been saying for years. We live in the coldest era of Earth’s history. It has almost always been warmer than now. Warmer is the normative condition. Better for Life as we know it.

    Warmer is Better — Fight the Ice

  32. paminator says:

    G Alston- Actually there have been a number of studies, summarized in a paper by Segalstad, with measurements from the 1950’s thru the 1970’s, that pin it down to 5-7 years as the residence time for CO2 in the atmosphere. The much larger numbers come from IPCC authors who claim that CO2 cycles many times from atmosphere to surface before being sequestered. Of course, if you adopt this approach to the calculation, then the resident time of water vapor is also years or decades, since it cycles many times prior to being sequestered at either pole or in a glacier.

    The 5-7 year number is based on measurements. Anything longer is based on models.

  33. johnrobert says:

    Given the reality of anthropogenic global warming, and in light of the political effectiveness of exxonogenic climate skepticism, maybe it would be more accurate to say that the Earth *was* on a 50-million year cooling trend.

  34. G Alston says:

    paminator — Yes I’m vaguely aware of the studies, and the upshot is that the cycling prior to sequestration is completely unknown, hence the answers always being all over the map. (Does this take 1 cycle? 23? Anyone? Bueller?) I would guess that GCM’s have a supposition of what this longevity is as a basis for calculations. Change it and the predictions change. This in turn suggests that GCM’s get their closest predictions (and in hindcasts at that!) by dialing longevity up. I can’t think of any other reason the IPCC and their supporters (minions?) keep claiming that CO2 atmospheric residency is up to 200 years.

  35. Joel Shore says:

    G Alston says:

    Really? How long? I’ve seen estimates that range from 10 years to 200 years, and these are from the alarmist crowd. The IPCC certainly doesn’t have a reliable and solid answer. There not only doesn’t appear to be a standard answer, implying that nobody knows *anything* about this that can be reliable, but the answers that come seem rather plastic. Depends on what the question was.

    The different answers that you see represent not so much uncertainty but rather the fact that the concept of a lifetime for CO2 in the atmosphere is ill-defined because when a slug of CO2 released into the atmosphere, the concentration decays in a very non-exponential fashion. Thus, it is not characterized by a single lifetime. Roughly speaking, about half of it disappears almost right away, another quarter of it stays around for hundreds of years, and the final quarter stays around essentially “forever” from the point of view of human timescales (e.g., tens to hundreds of thousands of years). See the discussion here: http://www.realclimate.org/index.php/archives/2005/03/how-long-will-global-warming-last/

  36. Jeff Alberts says:

    I’m also skeptical of the CO2 atmospheric residence time given as hundreds of years. If it’s so, and temps have “suddenly” jumped in the last 30 years, then the longevity of 200 years is pretty much bunk. CO2-caused warming would have been slower and longer if the climate were responding to every single tiny increase since the Industrial Revolution.

  37. Jeff Alberts says:

    The 5-7 year number is based on measurements. Anything longer is based on models.

    So that means CO2 and SO2 from high-alititude eruptions stay in the atmosphere about the same amount of time.

  38. Ed Scott says:

    Anthony,

    Have you previously posted this article by Dr. Roy Spencer: http://globalwarming-arclein.blogspot.com/2008/02/roy-spenser-on-co2-anthropogenic.html
    Atmospheric CO2 Increases: Could the Ocean, Rather Than Mankind, Be the Reason? by Roy W. Spencer,1/25/2008?

    The article predates my monitoring of Watts Up With That?

  39. Bill Marsh says:

    Meanwhile — a full 20 F below average in DC today. Avg high in DC in Sept 81, currently 61F

  40. Joel Shore says:

    Dan Lee says:

    Finally, some perspective. An atmosphere that has remained stable enough to support the 3+ billion year evolution of life, through all these extremes, isn’t going suddenly spiral out-of-control into a life-baking oven when it hits 400 ppm of CO2.

    If you take away atmospheric positive feedback, aren’t we done? End of show? Nothing left for AGW to stand on?

    Your whole argument rests on a number of misconceptions that I will try to clear up:

    (1) No serious scientist that I know of is claiming that there is a Venus-like instability and the climate is going to “spiral out-of-control into a life-baking oven” once CO2 levels hit 400ppm. The positive feedbacks just magnify the warming due to CO2 alone…They are not strong enough to lead to an instability. (On Venus they could because it is closer to the sun and hence receives more W/m^2 of solar energy.)

    (2) The concept of “tipping points” is used rather confusingly in a variety of contexts. There are the possibility of some true tipping points, like a sudden shift or shutdown of ocean currents…and there is evidence that this has happened in the past. Some people, like Hansen, have also used the concept of tipping points more loosely to talk about a point beyond which, given the positive feedbacks due to melting arctic ice and so forth, we will be committed to enough temperature rise to cause, say, several meters of sea level rise (with considerable controversy remaining over how fast that rise could occur).

    (3) Noone serious is claiming that the temperature reached will be a temperature that have never been experienced before in the geological history of the earth. However, what is being said is that they are temperatures that have not been experienced in quite some time (probably in the entire history of our species) and that the change will be very rapid relative to past temperature changes and will thus cause problems for both human civilization (a healthy fraction of which lives pretty close to sea level) and ecosystems (which are already being severely stressed by pollution, overfishing, habitat fragmentation, etc.)

    (4) The lessons that scientists have learned from studying paleoclimate data is, contrary to what you seem to believe, that their current estimates of the climate sensitivity are likely correct…or, if anything, too low to account for what has happened in the past. See, for example, this paper: http://www.sciencemag.org/cgi/content/summary/sci;306/5697/821

  41. Retired Engineer says:

    How long does CO2 stay in the atmosphere?

    At current concentrations, the atmosphere has about 2*10^12 tonnes of CO2. Assuming a total contribution (nature and man) of 200*10^9 tonnes, that gives an average lifetime of 10 years.

  42. Joel Shore says:

    Paminator:

    The question of interest is not how long it takes a given CO2 molecule to cycle through. Rather it is how long it takes the atmospheric concentration to be restored to within a certain percentage of its initial value after a slug of CO2 (that has been sequestered from the atmosphere, e.g., in the form of fossil fuels) has been released into it. Hence, your statements about residence times, even if correct, are irrelevant to the discussion.

  43. jmrSudbury says:

    Sudbury? We cut down our trees long ago for open crib burning (which turned our rocks black and killed lichen) and to help rebuild Chicago after the fires. The lack of trees allowed soil erosion making the soil erode downhill off the rock. Most plants don’t grow very well on the exposed rock.

    Northern Ontario lakes between here and North Bay are indeed acidic and thus not as conducive to life as they should be. Many lakes have been limed and many people lime their yards, but that won’t stop plants that tolerate the acid from growing like birch and blueberries. It is the erosion that did us in. You can see it using google maps to search for gps coordinates 46.48 -81.0 Zoom out a bit and you can see the brown oval.

    John M Reynolds

  44. Gary Gulrud says:

    “If CO2 is such a great warmer it should be something that could be duplicated in a lab.”

    Indeed. Heh.

  45. Steve Huntwork says:

    Retired Engineer (13:27:28) :

    How long does CO2 stay in the atmosphere?

    After nuclear weapons were created, it was rather simple to trace how long CO2 stayed in the atmosphere. The result was 7 years on average.

  46. John Nicklin says:

    At 385ppm, the Earth is still short of CO2 that plants need to use in photosynthesis. Even the CO2 deficite-tollerant plants that we have today would stop growing and die if atmospheric CO2 dropped to around 180ppm or lower.

    If CO2 levels drop, plants will become less hardy. Our pitifull little species is totally dependent on plantlife which depends on CO2. I don’t know what they teach in biology these days, but the CO2-hating greens should be more descriptively called the browns, lower CO2 will lead to plant die-off, not a green revolution.

  47. Bruce Hall says:

    The trend appears to portend a Mars-like future more than a Venus-like future.

  48. John-X says:

    Folks, global warming has just become SERIOUS!

    I could not care less about shrinking ice sheets, but THIS…

    http://www.dailymail.co.uk/tvshowbiz/article-1061809/Is-Jennifer-Lopezs-famously-rounded-derri-actually-SHRINKING.html

    WE MUST TAKE ACTION NOW!

  49. Ray says:

    jmrSundbury get your history and chemistry straight. The vegetation holocaust in Sudbury was cause by The Inco Mine. The plume and devastation can be seen from space. http://www.sprol.com/?p=64

  50. SteveSadlov says:

    RE: Pieter F (12:16:49) :

    It would be interesting to get Doug Erwin’s take on what you wrote. I interfaced with him a bit early in his career, and found him to be a very forward thinking individual. I would definitely not discount what you have have outlined.

  51. Ed Scott says:

    Joel Shore

    I linked to your reference: http://www.sciencemag.org/cgi/content/summary/sci;306/5697/821
    Their findings on the sensitivity of the climate system I assume is true. The speculative sensitivity of the climate system to climate models is invalid.

    “Climate models and efforts to explain global temperature changes over the past century suggest that the average global temperature will rise by between 1.5º and 4.5ºC if the atmospheric CO2 concentration doubles.”
    “They conclude that the climate system is very sensitive to small perturbations and that the climate sensitivity may be even higher than suggested by models.”

    It should be obvious that Nature is not subject to the control of models. The authors “suggest” and say “if” about facts not in evidence and say “maybe” about “suggestions” made by unverified models.

    Spinning speculation does not create scientific fact.

  52. SteveSadlov says:

    RE: Bruce Hall (14:04:25) :

    That is my fear as well. I keep beating the interstellar migration planning drum. We need to start planning now. Unless there is a break through in technology and our understanding of physics, we need to allow a few million years to move everyone, and that is after we actually determine where to move to. We need to assume that the space transport technology will still be way below light speed, when we need to move. If things get easier, then great, icing on the cake. But if they don’t we need to plan and execute multigenerational space emigration on a massive scale.

  53. Pete says:

    My understanding of the atmospheric CO2 levels is that there are 2 main physical cycles going on that are going on together. On top of that you have the biological and

    One cycle involves the rate of absorption into surface Ocean water of a slug of CO2. To understand this cycle you have to assume an ocean that does not have large scale upwellings and downwellings. Simple diffusion physics combined with wind/wave surface mixing are the mechanisms. This is the cycle that I understand is on the order of 5-10 years.

    The other cycle is driven by the longer term Ocean current driven upwellings and downwellings. This can drive CO2 up or down . I understand the simple version of this is that when the older water was at the surface it would have reached close to a an equilibrium concentration of CO2 as influenced by atmospheric CO2 concentration and surface water temperatures at that time. That time is based on the oceanic cycles and I’ve heard 200-800 years. This may actually be represented by several distinct oceanic cycles. Perhaps one for the Atlantic, a couple in the Pacific, etc. So notionally, the Atmospheric Co2 concentration levels may be significantly represented by a 5-10 year equilibrium cycle, on top of 200, 600 and 800 year oceanic cycles.

    And this is why modeling of ocean currents is much more significant an area of research to understanding and projecting CO2 levels.

  54. Neil Crafter says:

    Joel Shore:
    (1) No serious scientist that I know of is claiming that there is a Venus-like instability and the climate is going to “spiral out-of-control into a life-baking oven” once CO2 levels hit 400ppm.

    The name Hansen rings a bell perhaps?
    Or perhaps he’s not a ‘serious’ scientist………

  55. Dan Lee says:

    Joel Shore,

    They can’t have it both ways. You’re suggesting that there is a second “tipping point” (or “blocking point”) somewhere in the future that causes the positive feedback to stop.

    But I haven’t seen that anywhere else. I would be happy to learn where the AGW theory says that increasing warming will come to an end, the positive feedbacks will stop, and the atmosphere will stabilize.

    To the contrary, we have eminent, award-winning scientists like Jame Lovelock predicting that, “Before this century is over, billions of us will die, and the few breeding pairs of people that survive will be in the Arctic where the climate remains tolerable.”

    http://www.independent.co.uk/environment/environment-in-crisis-we-are-past-the-point-of-no-return-523192.html

    With a heat source assumed to be steady (the sun), and an increasingly warm, thick and efficient atmospheric blanket to lock that heat in, what is going stop the warming? Especially with all the extra CO2 and soon methane etc. predicted to come pouring in real soon now?

    So again, does the AGW hypothesis really say that temperatures will stop spiraling upward at some point? Do you (or does anyone) have a link or a reference? This is the first time I’ve heard of warming being predicted to come to a stop somewhere down the road.

  56. Steve Keohane says:

    This is basically the same chart Smokey posted, accredited to Scotese, 2001,
    a year earlier. It is a bit easier to read, and shows regardless of the CO2 levels,
    temperature has never run away. Even at 4000ppm temperatures have been similar to today’s. There simply is no tipping point from CO2 levels. Historically, CO2 levels are about as low as they get, and temperature is too. So ‘normal’ is having both be higher.

  57. Ed Scott says:

    Joel Shore

    You write: “… what is being said is that they are temperatures that have not been experienced in quite some time (probably in the entire history of our species) and that the change will be very rapid relative to past temperature changes…”

    It is not what is being said, it is who is saying what the temperatures will be and that the temperature change will be relatively very rapid.

    Do you have any scientific facts to back these assertions?

  58. Re Lovelock. Why then is humanity concentrated near the Equator rather than at the poles right now? I mean if warmer is so deadly and all, how come most people live in tropical or semi-tropical environments?

    Re rising sea levels. Why not move to higher ground rather than to distant planets? What exactly is the point of building cities below sea level when the continents have plenty of room?

    Wouldn’t that be more constructive than economic monkey wrenching and civil disobedience? I’m just saying…

    Re the demise of ecosystems. Gimme a break. Most plants and animals evolved on a much warmer planet. The Ice Ages have been the driver of most extinctions in the last few million years. Plant and animal species move around. Yes they do. The harum scarum dire reports of ecosystem collapse are exaggerated foolish nonsense.

  59. Bill Illis says:

    A better way to think about CO2 residence time is “how long will the increased CO2 stay in the atmosphere (presumably causing warming)” which is the reason to ask the question in the first place.

    How long will it take for CO2 levels to return to normal levels?

    Right now, natural processes (oceans and plants) are absorbing about 2 ppm of the additional 4 ppm humans are adding to the atmosphere each year.

    If we have increased CO2 about 105 ppm (from 280 to 385), natural processes will return CO2 to its pre-industrial level in about 50 years if current trends continue.

    More likely, natural processes will slow down as the CO2 levels drop, so the best estimate would be 50 to 75 years (the same length of time we have been adding CO2 in a serious way.)

  60. Ed Scott says:

    Joel Shore
    “Your whole argument rests on a number of misconceptions that I will try to clear up:”

    A very informative comment.

  61. Mick says:

    Hi everyone,
    I wonder if any study is exist regard of the heat coming up from the deep, natural decay which would drive the deep ocean temperature?
    If not the Sun drive the climate (IPCC) this maybe the variable not used for
    computer modelling. LOL

    How about the continental drift generated heat? Is there are any correlation
    of the continental drift and the Solar system barycenter motion?
    Sorry about the naive questions…. :)

    Mick.

  62. jmrSudbury says:

    Ray, the crib burning is the smelting process Inco used near the turn of the century. Thanks for the link. That shows the superstack that was built in 1972 that ended up sending the smoke farther away. Now a larger area is affected.

    By the time the superstack was built, the soil was already eroded and there were few trees left as noted by NASA using our landscape as a test drive for their lunar rover in the 60s once. Some damage was done by Inco and other mining companies after crib burning was abandoned, but it was the cribs that did the bulk of the damage by using the wood. My point is that soil erosion was worse than sulfur dioxide when it came to our vegetation. It is correct that the soil that was left does best now if it is limed first for most garden plants, but it took decades of acid rain to do the damage.

    Now a days, Inco monitors the direction of the smoke plume and particulate emissions. They judge when they need to issue certificates for repainting cars that were beneath the plume when the emissions were too high and created pox marks in the paint of vehicles left outside.

    I suspect it would be similar with volcanoes. The rain going through the concentrated plume would cause the most devastation, but if the eruptions are not constant, like Sudbury’s plumes of smoke over decades, then the lake would be able to adapt or heal itself. As well, the soil would have the acid washed through when the sulfur was done being washed from the air.

    John M Reynolds

  63. Michael J. Bentley says:

    (Sound FX) An explosion off set

    (Narr: Walks on stage, clears throat) Ladies and gentlemen, our writer has just exploded due to an overdose of Al Gore. We will continue now with the program as written in your programs.
    (Narr: Walks off stage)

    Just read on ICECAP that Gore asked young people to demonstrate against coal fired plants that don’t sequester CO2. I think I’m going to be sick – using our youth like this. Hate to say it but this is very similar to another situation in a mid-european country in the second third of the last century.

    (moderator: Mr Bentley, you’re banished!)

    ARGGGG!

    Mike

  64. Ray says:

    John, I would think that the volcano eruptions was the norm back then and lasted many million years. You’ve seen the damage in Sudbury. How much damage to the plants and soil would million of years of volcanic acitivity do to the earth back then?

    I am not suggesting anything but this is something else to add to the equation and not just consider CO2 and global warming.

  65. Tom in Florida says:

    Need some help. My neighbor has gone back to community college in order to change careers. One of his required courses is Interdiscipinary Sciences (whatever that is). The professor is an AGWer and my neighbor has brought up some points that I have passed on to him from this blog. The professor told him to ask me 3 simple questions, the answers proving AGW:
    1) are there more cars than in 1950?
    2) are there more aircraft than in 1950?
    3) are there more coal electrical plants than in 1950?
    I retorted, “And what is that supposed to prove?” but I can guess his drift.
    I want to send my neighbor back with a couple of questions to see how much this professor really knows about CO2. I know I have seen this information on this blog but do not have any idea where to look for it so if anyone can provide the answers, or better questions, thank you so much
    My questions will be:
    1) What is the absorption spectrum of CO2 and at what point does it become saturated? How does that compare to the absortion spectrum of water vapor?
    2) What percent of the atmospheric CO2 is man made?
    3) What is the lowest level that atmospheric CO2 can drop to before plant life dies?
    4) What is the highest level that atmospheric CO2 has risen to where life still existed?

  66. Joel Shore says:

    Dan Lee says:

    But I haven’t seen that anywhere else. I would be happy to learn where the AGW theory says that increasing warming will come to an end, the positive feedbacks will stop, and the atmosphere will stabilize.

    There is still some confusion here. It is not so much that the “positive feedbacks will stop”. It is that they are strong enough to cause amplification of the warming but not an instability.

    To give you an idea of the mathematics that comes into play here: Let’s say that for every 1 deg rise we cause in the temperature due to the direct effects of increasing CO2 levels, the feedbacks (e.g., an increase in water vapor) lead to another 1/2 deg rise. Then you will say, “But, wait, then the feedback on that 1/2 deg rise will lead to even a further rise.” And, indeed this is true. But, that additional rise will be only 1/4 deg. Then the feedback on that will lead to another 1/8 deg rise. What you get is an infinite series 1 + 1/2 + 1/4 + 1/8 + 1/16 + … However, even though the series has an infinite number of terms, this sum does not diverge. In fact, it approaches 2. So, in the simple toy model that I have described to you, the effect of the feedbacks is to double the warming.

    The current best estimates of the climate sensitivity correspond to the feedbacks magnifying the warming by about a factor of ~1.5 (or a little more) to 4.

    As for Lovelock’s scenario, I won’t try to defend it as it seems extreme to me. On the other hand, as disasters like Katrina and economic problems like the current housing crisis show, our societies are not as far from degenerating quite a bit as we may like to believe. So, while I think Lovelock’s climate scenario is extreme, I do think that a milder climate change scenario could still cause enough societal troubles (wars over resources, etc., etc.) to be more serious than we might otherwise expect.

    Finally, in my last post when I talked about Hansen’s using the term “tipping points” rather loosely, I may have missed something: I think one important point that Hansen is making is that the positive feedbacks lead to a lot of “hysteresis” and “irreversibility” in the climate system. What I mean is that if we raise the CO2 levels beyond a point where a lot of melting of arctic ice occurs then the positive feedback due to having less ice to reflect the sun will lead to further warming. Also, the way that the ice sheets break up is highly nonlinear and can be much faster than it takes to build them up again.

    What this implies is that if we go beyond a certain point and then drop the CO2 levels back down again, temperatures and land and sea ice will not simply go back to the way they were…at least for a long long time. (And, in fact, the ice sheets will continue melting and the sea levels rising.) I think this is the sense in which Hansen is talking about a tipping point…and it is a quite reasonable use of the term. It is not that the temperatures are going to spiral out-of-control but simply that they will likely go to levels that we humans have not experienced and the effects, especially the melting of ice sheets and rises in sea levels, will not be easy to stop even if we are able to stabilize or even start to reduce CO2 levels.

  67. Joel Shore says:

    Mick says:

    Hi everyone, I wonder if any study is exist regard of the heat coming up from the deep, natural decay which would drive the deep ocean temperature? If not the Sun drive the climate (IPCC) this maybe the variable not used for
    computer modelling.

    Yes…I have seen some estimates somewhere of a W/m^2 forcing due to heat coming up from the earth and, as I recall, it is down by at least a few orders of magnitude from the forcing due to CO2. (Needless to say, it is even a few more orders of magnitude down from the total energy that we receive from the sun).

  68. Robert in Calgary says:

    Say Tom,

    Ask him to name -all- the greenhouse gases and what percentages they are. And then what the human contribution is to CO2, perhaps in comparison…say, to cows.

    Show him the Hansen 20 year graph and ask him to point out which end is cooler.

    Or get him to critique the Monthly Weather Review from…was it Sept. 1933, that Anthony had here earlier in the year.

    ….and buy him a copy of “The Chilling Stars”

  69. Pieter F says:

    Tom in Florida: Your friend might also mention that there are more whales than in 1950 (one blue whale breath emits more CO2 than a thousand people would). Those pagophylic (ice-loving) bowheads are many times more numerous than in 1950 despite continued predation by Inupiat Eskimos.

    Also mention that the world climate (as measured by eustatic sea level) is about a meter below the Late Holocene Interglacial average, representing about 1°C cooler than the average during the period of human civilization. The maximum sea level during this period was about 3 meters higher than now. We are well within normal climate flux for an interglacial.

    Yet another item worthy of mention . . . we have deforested tremendous parcels of rain forests, both tropical and temperate. Make sure the Third World contribution to anthropogenic carbon in the atmosphere is included in any conversation. Third World home fires contribute more than 50% of the anthropogentic CO2. Ocean pollution is also responsible for a double digit percentage of the residual CO2 each year. Cars and aircraft are a relatively small percentage.

  70. Fernando ( in Brazil) says:

    Mike:
    I am a more naive. Together
    If the sun is distant 150000000Km your temperature is 6000 ° C on the surface. The center of the earth is 6000 º C. and your distance to the surface 6500Km.
    earthspot number (????)
    What is the energy used to move the American continent 1mm by year? (seriously)

  71. Richard deSousa says:

    Smokey: That’s some graph! There doesn’t seem to be any co-relation between temperature and CO2.

  72. Ed Scott says:

    Tom in Florida

    As a start, visit: http://www.geocraft.com/WVFossils/ice_ages.html#anchor2108263.

    The link “Causes of Global Climate Change” leads to a discussion of the “Greenhouse Effect.” Table 1, from the DOE, October, 2000, gives the pre-industrial base-line and reports the natural and anthropogenic additions separately. I have yet to locate more recent DOE data. If the ratio of natural to man-made CO2 of 5 to 1 holds, then the man-made portion of the CO2 increase of 17 ppm, since 2000, would be about 3.5 ppm

    There are references to supporting books, articles and reports.

  73. Paul Moberg says:

    Fishing the NW Passage!

    Damn!!!

  74. Dan Lee says:

    Joel Shore,

    Good explanation, and good clarifications, thanks.

    I like your sequence of diminishing returns on the feedback, that clarifies things a lot. It matches very well with our understanding of the diminishing GHG contribution of CO2 as its level increases, and jives with the idea that we’ve already seen about as much warming from CO2 as we’re going to get.

    I’m aware of a .6C/century greenhouse contribution of CO2, and as you say you would still need that positive feedback to get the IPCC’s 1.5C – 4C rise in temps due to water vapor. I guess that’s in tatters at this point, as your example indicates, unless they mean the entire warming that CO2 will ever produce.

    I’ve lived in third-world slash-and-burn agriculture economies (with the Cuiba Indians in Colombia) and I know that a group of primitive families can dump more CO2 into the air in one week than my neighborhood full of SUV’s produces in a year. Mankind has been pouring smoke into the atmosphere since we discovered fire, so I also have difficulty with the general assertion that man-made CO2 only started to become relevant since about the 1950’s.

    Anyway, if CO2 and water vapor were the only two factors at play, then the IPCC’s take might make sense.

    But they’re not the only factors. The warming signal from the ocean oscillations is huge, big enough that you can point at the temp graphs and they jump right out at you. Where’s the positive CO2/water-vapor signal? Buried in the natural warming since the last ice age? Or even since the LIA?

    I’m not seeing much room for a positive feedback hypothesis between water vapor and CO2 to explain the trends over the past century. Or the past millenia, to bring this back on topic, and refer the conversation back to the temperature chart at the top.

    With such huge natural variations, and if as you say the positive feedback (if it is indeed positive) is minuscule, then what exactly is the point of pushing forward a positive feedback hypothesis in the first place? Especially without accounting for the possible negative feedbacks, such as increases in clouds and rain?

    What’s the point of trying to do away with a huge body of historical and scientific work on the Medieval Warm Period and the Little Ice Age by drawing hockey-stick graphs UNLESS one wants to discount natural cycles as an explanation for recent temperature trends?

    If all one is willing to accept as an explanation is man-made CO2, then one needs to believe in positive, catastrophic feedbacks and one needs to ignore past variability.

    I accept your explanation of the IPCC’s position on the feedbacks, but I find it (the IPCC’s) frustratingly incomplete. They fail to adequately address both natural variability and the effect of negative feedbacks.

    Therefore I am skeptical of their pronouncements about future climate. But I feel that I understand them better now, thanks to your explanations. Sincerely appreciated.

    Now if only I can get my kids’ science teacher to quit telling them our whole neighborhood will be underwater in 20 years. :-/

  75. Bill Illis says:

    Just thought I’d post a longer version of the temperature history of the planet (540 million years) versus the one originally linked to by Peter in the opening of the post. (This version is no longer linked to by Wikipedia but seems to be the best analysis of the paleotemps over the last 540 million years).

    This chart is the CO2 history of the planet over the same 540 million years. The yellow orange line from Berner seems to be the most accepted. (earlier in the thread, a CO2 history from Pagani was linked to but Pagani is a rabid warmer and as such should not be viewed as objective.)

    http://www.globalwarmingart.com/wiki/Image:Phanerozoic_Carbon_Dioxide_png

    One could do their own math on how much doubled CO2 leads to increased temperature in this long paleoclimate history. (Hint: it works out to 1.0C to 1.5C per doubled CO2 ignoring the fact that the Sun was not as energetic in the distant past. One might have to have to raise the climate sensitivity figure to 1.5C taking this into account.)

  76. Jeff L says:

    A lot of posts earlier about SO2 vs CO2 in volcanic eruptions. Just to follow up, as a geologist myself, here’s a bit more geology. There seems to be some confusion on what kind of eruptions we are talking here. The “Deccan traps” are a flood basalt eruption. Why is that key? These are eruptions of low viscosity basaltic lava that does not form large volcanoes – such as a Pinatubo. No explosive injection of SO2 into the stratosphere. Completely inconsistent with this type of volcanism. So it really doesn’t matter how much SO2 vs CO2 was being degassed – the SO2 will be ineffective as it will never reach the stratosphere. Now as for acid rain or other hypothesis, that may be a different story.

  77. anna v says:

    Dan Lee (15:04:13) :

    “With a heat source assumed to be steady (the sun), and an increasingly warm, thick and efficient atmospheric blanket to lock that heat in, what is going stop the warming? Especially with all the extra CO2 and soon methane etc. predicted to come pouring in real soon now?

    So again, does the AGW hypothesis really say that temperatures will stop spiraling upward at some point? Do you (or does anyone) have a link or a reference? This is the first time I’ve heard of warming being predicted to come to a stop somewhere down the road.”

    Albedo?

    If you watch the water temperatures in the tropics http://weather.unisys.com/surface/sst.html for a while, you will see that it never gets over 30 or so C.
    That is becaus after that evaporation becomes significant, clouds thicker, albedo grows and thus more energy is reflected back instead of being absorbed. A natural thermostat.

  78. Richard Sharpe says:

    Hmmm, but then another article in the 23-Sep-2008 issue of PNAS has this to say:

    The observed increase in the concentration of greenhouse gases (GHGs) since the preindustrial era has most likely committed the world to a warming of 2.4°C (1.4°C to 4.3°C) above the preindustrial surface temperatures. The committed warming is inferred from the most recent Intergovernmental Panel on Climate Change (IPCC) estimates of the greenhouse forcing and climate sensitivity. The estimated warming of 2.4°C is the equilibrium warming above preindustrial temperatures that the world will observe even if GHG concentrations are held fixed at their 2005 concentration levels but without any other anthropogenic forcing such as the cooling effect of aerosols. The range of 1.4°C to 4.3°C in the committed warming overlaps and surpasses the currently perceived threshold range of 1°C to 3°C for dangerous anthropogenic interference with many of the climate-tipping elements such as the summer arctic sea ice, Himalayan–Tibetan glaciers, and the Greenland Ice Sheet. IPCC models suggest that ≈25% (0.6°C) of the committed warming has been realized as of now. About 90% or more of the rest of the committed warming of 1.6°C will unfold during the 21st century, determined by the rate of the unmasking of the aerosol cooling effect by air pollution abatement laws and by the rate of release of the GHGs-forcing stored in the oceans. The accompanying sea-level rise can continue for more than several centuries. Lastly, even the most aggressive CO2 mitigation steps as envisioned now can only limit further additions to the committed warming, but not reduce the already committed GHGs warming of 2.4°C.

  79. Stef says:

    50 million year global cooling trend? Pffff. It’s just a regional weather blip, nothing to do with a 30 year climate measurement. The science is settled.

  80. Mikey says:

    I hope I’m not too late too ask a question, but I was reading that great new paper from Lindzen where he goes into all the dirty dealings in the back rooms of climate science.

    There’s this one part where he’s talking about how when the models won’t line up with the data, they just re-imagine the data, or something like that. He mentions the Eocene. Here’s a quote…

    “In the first example, the original data analysis for the Eocene (Shackleton and Boersma, 1981) showed the polar regions to have been so much warmer than the present that a type of alligator existed on Spitzbergen as did florae and fauna in Minnesota that could not have survived frosts. At the same time, however, equatorial temperatures were found to be about 4K colder than at present. The first attempts to simulate the Eocene (Barron, 1987) assumed that the warming would be due to high levels of CO2, and using a climate GCM (General Circulation Model), he obtained relatively uniform warming at all latitudes, with the meridional gradients remaining much as they are today. This behavior continues to be the case with current GCMs (Huber, 2008). As a result, paleoclimatologists have devoted much effort to ‘correcting’ their data, but, until very recently, they were unable to bring temperatures at the equator higher than today’s (Schrag, 1999, Pearson et al, 2000). However, the latest paper (Huber, 2008) suggests that the equatorial data no longer constrains equatorial temperatures at all, and any values may have existed. All of this is quite remarkable since there is now evidence that current meridional distributions of temperature depend critically on the presence of ice, and that the model behavior results from improper tuning wherein present distributions remain even when ice is absent.”

    OK, I admit I don’t understand that, nevertheless my question is this. Could this new report, or whatever it is from NAS, be directed to offering up a solution for the issue Lindzen describes? I mean could it any way help the models line up with the data?

  81. Dan Lee says:

    anna v

    Exactly right. I’ve spent most of my life in the tropics and subtropics, and I see the negative feedbacks almost daily. We don’t have four seasons per se, we have two: rainy season and dry.

    Dry season tends to be cooler and less humid. In rainy season, as we’re in now, the humidity can be oppressive at times, but then every afternoon like clockwork the clouds build up and we get absolutely drenching thunderstorms. These last for a few hours, then by evening it clears up and leaves the air mild and pleasant.

    That’s why I’m always complaining about the assertion of positive feedbacks by AGW proponents. A lifetime of paying attention tells me that the relationship between warmth and atmospheric concentration of water vapor is clearly and obviously dominated by NEGATIVE feedbacks.

    The clouds roll in and you can feel the temps drop. The daily afternoon rain and wind cools things further. Air that was thick and heavy in late morning is light and fresh by late afternoon.

    The folks who sit in offices in the northern US and in Europe and theorize about the relationship between heavy concentrations of GHGs (water vapor) and warmth should take a break and spend some time down here where they can see what that relationship is really llike. They’ll forget about positive feedbacks in a big hurry.

  82. tty says:

    Tom in Florida:

    The answer to the professor’s question 2 is “No”. While there are more civil aircraft now there is vastly fewer military aircraft. In 1950 both the USA and the SSSR had literally tens of thousands of military aircraft each, as against just a few thousand now. Proportions are similar for many other countries.

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  84. Stefan says:

    Dan Lee:
    I’ve spent most of my life in the tropics and subtropics, and I see the negative feedbacks almost daily.

    Yes, I too grew up in tropical climates. And it does make one wonder that these climate modellers could stop staring at their computer screens and get out of the office more.

  85. Dee Norris says:

    @Dan Lee

    Mature stage clouds of a thunderstorm have a down draft of cold upper troposphere air. The experienced surface temperature change is a result of this downward draft.

  86. DR says:

    Dan Lee and Dee Norris

    Your observations agree with satellite data. Observational evidence seems to have been abandoned by certain factions of climate “science” in favor of simulations and scenarios via untested modeling.

    http://www.weatherquestions.com/Spencer_07GRL.pdf

  87. Roger Carr says:

    Michael J. Bentley (16:18:39): “Just read on ICECAP that Gore asked young people to demonstrate against coal fired plants that don’t sequester CO2. I think I’m going to be sick – using our youth like this.”
    Fully endorsed, Michael.

    Reply – As I pointed out in An Inconvenient Youth, our children are being manipulated into unquestioning acceptance of the AGW agenda. Now they are being steered toward criminal behaviors against society. How many really can distinguish the fine line between civil disobedience, civil infractions and civil insurrection? – Dee Norris

  88. Gary Gulrud says:

    “Right now, natural processes (oceans and plants) are absorbing about 2 ppm of the additional 4 ppm humans are adding to the atmosphere each year.”

    Daily variance of CO2 measured by AIRS in mid-troposphere and at 10,000′ at Mauna Loa is on the order of 10^1 ppm, this corresponds to a daily fluence between ocean and atmosphere of on the order of 100 Gtons!

    Spencer in Jan. posted that the variance in 13C12 fraction of the seasonal signal in the Mauna Loa data and long term trend were identical, i.e., following from the same source.

    These points have been made by posts here at Watts’ posts and are easliy retrieved. The quoted statement is utterly unsupported by the evidence.
    The anthropogenic contribution cannot be isolated by any means whatever and repeating this nonsense is no longer mere ignorance.

  89. Bruce Cobb says:

    Tom: Those are good questions. You could also have him ask the “professor” What caused the Roman and Medieval Warm periods, and what caused the LIA? Also, what caused the 2.2C jump in temp. from 7.8 in 1696 to 10.0C in 1732 (2.2C in 36 yrs)?

  90. kim says:

    Salute the brave hockey moms as they thread their way deftly with their suburban assault vehicles through the frontlines of the Carbon Liberation Wars. Save the Baby Ice but beware the Great Great Many Great’s Granma Ice.
    =============================================

  91. Bobby Lane says:

    Good posting here on the “Greenhouse Effect” that everyone thinks they know so much about, but apparently really don’t as you will find when you read. The most surprising (yet really not) part to me was that over and over Mr Kininmonth, meteorologist and head of Australia’s National Climate Centre from 1986 to 1998, and author of Climate Change: A Natural Hazard, says that “Essentially, the role of greenhouse gases is to cool the atmosphere” and this works with “surface warming from solar radiation” to form clouds. Clouds both heat and cool the atmosphere, trapping heat under them but radiating incoming solar energy away from the ground. They are the great equalizer. “But this takes the wind from the sails of the AGW folk,” says Mr Kininmonth. I would have to agree.

    http://jennifermarohasy.com/blog/2008/08/william-kininmonth-on-the-radiation-of-energy-and-global-warming/

  92. Ed Scott says:

    Tom in Florida

    Here is the link to the green-house effect, which was omitted from my previous post: http://www.geocraft.com/WVFossils/greenhouse_data.html

  93. Bill Illis says:

    The Global Carbon Project (the official agency tracking carbon emissions) just released the new numbers for 2007.

    Carbon emissions are now 8.5 billion tons per year (4 ppm).

    Land and Oceans are absorbing 54% of this amount (2 ppm).

    CO2 level therefore rising at 2 ppm per year.

    http://www.globalcarbonproject.org/global/ppt/GCP_CarbonBudget_2007.ppt#806,1,Slide 1

  94. Jeff Alberts says:

    The folks who sit in offices in the northern US and in Europe and theorize about the relationship between heavy concentrations of GHGs (water vapor) and warmth should take a break and spend some time down here where they can see what that relationship is really llike. They’ll forget about positive feedbacks in a big hurry.

    Well, they all went to Bali a little while ago, but I think the presence of too many bikini-clad girls prevented them from really understanding climate. That, and a foregone conclusion…

  95. sammy k says:

    windpower, like ethonal and solar is unreliable and uneconomic without taxpayer subsidization…heavily burdened taxpayers are being duped by archer daniels midland, t bone pickens, general electric and hansen and gores’ doom and gloom infomercials to line their own pocket….instead of talking about hot air, whether it sometimes turns a bladed monolith to stupidity, or how its causing the earth to meltdown, we should be discussing how to solve this great country’s energy needs by developing our vast resources of homegrown energy…we should fire every one of our green-special-interest-pandering-to elite members in congress and push for natural gas cars, trucks, buses, more coal and nuclear plants as well as opening up all our places to drill, drill, drill….those that dont read history are bound to repeat it…remember the carter era when subsidization of wind, solar and oilshale was the answer to the oil embargo and high fuel costs?…sound familiar thirty years later?…when reaganomics put an end to all the “alternative” subsidies each of the sound good energy solutions including windfarms, all went broke…in contrast, when reagan eliminated the energy subsidies, a wonderful time of economic prosperity followed …look what is going on in our financial markets today because some DODDo’s decided bad loans is a good idea…alternative energy, like wind power is tomorrow’s wall street crisis, just like it ended up thirty years ago…if your not convinced green power is a taxpayer funded pipedream, then ask the europeans about their windpower, cap and trade fiasco, and the cost of their energy…instead of lining special interest pocket’s with subsidies, its high time America start producing and eliminate the transfer of wealth out of our country….there, i fell better….have a nice day!!!

  96. sammy k says:

    sorry, posted windfarm comments to wrong thread..tks

  97. Ed Scott says:

    Bill Illis

    DOE data shows the concentration of atmospheric CO2 to be 368 ppm on a chart dated October, 2000. Mauna Loa station gives the 2008 atmospheric (at 11,000 feet) CO2 concentration as 385 ppm, an increase in concentration of 17 ppm. From the pre-industrial base-line of 288 ppm of CO2, to the year 2000, natural emissions of CO2 contributed 68.52 ppm and man-made emissions contributed 11.88 ppm to the base-line, resulting in a concentration of 368.4 ppm. The ratio of natural to man-made emissions is 68.52/11.88 = 5.76767676…. Let us round off to a 5 to 1 ratio.

    The GCP report seems to indicate that this ratio has drastically changed. The change from the year 2000 to the year 2008 of 17 ppm averages 17/8 = 2.125 ppm per year combined natural and man-made CO2.

    The Mauna Loa station gives the yearly increase of CO2 as 2.14 ppm.

    Why does the GCP report say that natural sources (making a contribution of 5 to 1 until the year 2000) are now irrelevant and only contributing 0.14 ppm of CO2, which results in a ratio of 0.07/2.0 of natural to man-made CO2?

    What caused this anomaly to occur in the year 2000? I suspect a reduction in the ppm of scientific fact and reliance on the sacred model.

  98. Derek D says:

    Well, if you ever want to keep a dead issue going, convolute it!

    Gotta love the creativity these scientists going back 65 million years to try to show some correlation between CO2 and warming. You see, it has been well extablished that CO2 increases FOLLOW Warming by about 800 years. So how do you battle that if you are a “Warmist”. You graph CO2 versus temperature over 65,000,000 years, so that the 800 year lag basicially disappears unless you a examining a billboard sized graph with a microscope.

    Then you turn around and further convolute it by attributing the subsequent cooling to plate techtonics. How fitting. Plate Techtonics is very similar to Global Warming in that it has been accepted by consensus, despite much evidence to the contrary, and legions of non-believers almost as big as believers.

    Cooling of the earth over the last 65 million years is in fact easily explained by the “Expanding Earth” theory. More surface getting the same amount of sun, Voila cooling. Understanding how the plate techtonic mechanism would trigger this cooling trend is considerably more complicated. Almost as complicated as explaning how the Pangea theory could be accepted anyone with more than a 4th grade education.

    But hey it makes sense. As more and more reliable and compelling data threatens the high ground currently held by Global Warming and Plate Techtonics, it only makes sense that their combined powers to scare, confuse, and validate flawed models would be necessary to keep them relevant. Irrelevant as they may be…

  99. Ted says:

    Short term fluctuations are weather, NOT climate. You [snip] need to try to comprehend the difference. 50 million years does not a trend make.

    I think now is where I’m supposed to tell you all to “educate yourselves,” or something like that.

    Reply – The d-word is banned here. Like grains of sand become a beach, so does weather become climate. The vast majority here know the difference between the two and several are trained scientists. Also, all here use real email addresses and clearly your ‘sdgh@sg.sdf’ is not real. Repeated offenses often result in IP addresses getting banned. – Dee Norris

  100. Ted says:

    Mr. Norris-

    Apparently sarcasm is beyond your comprehension. I’m sure most other people here can understand the use of absurdity, to demonstrate absurdity. I know Anthony has a sense of humor, at least.

    Go ahead and ban me, if you want. I see no point in contributing here any more if humor is no longer permitted. And unless I’m making threats, it’s none of your business who I am. I expect you’d find that the addresses of MOST of your infrequent commenters are fake. I’ve used that address about once a week, for several months. No one ever said a word about it, until you showed you couldn’t understand an obvious joke.

    If you’re looking to pick a fight with climate alarmist, perhaps you should actually find one.

    REPLY: Ted the d-word as you applied to people present is not used here, sorry if you don’t like that, but it’s not negotiable. I also expect people to use real email addresses. Anonymous commentary while allowed, isn’t given the same weight as people that use their real names and have valid email adddresses. – Anthony

  101. Gary Gulrud says:

    “Land and Oceans are absorbing 54% of this amount (2 ppm).”

    I believe your Manifesto assigns 800 GTons of carbon as the size of the biogenic sink, primarily surface vegetation.

    During the day this sink lays up CO2 and expels CO2 at night. Yet the daily fluctuation results in an increase at 20,000′ of 6ppm in CO2 over the evening measure.

    This would lead one to reasonably conclude that the fluence between the ocean and atmosphere dominates. The temperature rises during the day, expelling CO2 and as the temperature drops during the evening the CO2 absorbed. Lets call that total 80 GTons. 1/10 of the entire biogenic sink, is entering and leaving the atmosphere daily!

    Spencer’s post here showed that while the biogenic sink prefers to lay up 12C and expells !3C that the seasonal signal, supposed by Keeling biogenic, is not distinguishable from the trend, the sum of all fluences by its 13C/12C fraction.

    Thus the ocean temperature determines the atmospheric abundance.

    What do you propose to as evidence that your piddling 2ppm is anthropogenic? The fact that the Manifesto says it is so?

  102. Bill Illis says:

    Gary, Land and Ocean daily and annual CO2 exchanges clearly dwarf human emissions.

    The last numbers I have seen is that Land (plants) and Oceans absorb 154 GTs per year and emit 150 GTs. This is compared to human emissions of 8.5 GTs per year.

    But we are adding Carbon to a system which was more-or-less balanced to start with. There is no point arguing humans are not contributing to the rise in CO2 concentrations when CO2 levels are increasing at 4 GTs per year (Carbon) and we are emitting 8.5 GTs per year.

    And the theory regarding Oceans absorbing Carbon is that cooler Oceans will absorb more and warmer Oceans will absorb less (emit more). If warming Oceans are responsible for all the CO2 increase, then global warming is real because rising Ocean temps are one of the things which should happen with global warming.

    Given that Ocean temps have not warmed over the last 4 years according to the best estimates, CO2 levels should have stabilized over the past four years if human emissions were not a contributing factor.

    Obviously, Ocean conditions and plant growth on Land are affecting the annual numbers . CO2 numbers jumped during the 1998 El Nino, for example. But we are adding 8.5 GTs per year to a system which was/is sinking 4.0 GTs per year on average so the net numbers are increasing.

    I think this is generally a good thing. That natural processes are taking in so much of what we are emitting. Maybe the natural processes, especially plants, will even accelerate and take more CO2 in. Then there will be nothing to worry about. No global warming and higher plant growth.

  103. Jeff Id says:

    We don’t even know the temperature 150 years ago. Look at the weather stations. We certainly can’t trust a 50 million year guess.

  104. Dan Lee: “That whole thing falls apart when either of the following are shown to be true: (1) there was more warmth in the past; (which didn’t trigger any positive feedback b/n CO2 and water vapor), (2) there was more CO2 in the past (which didn’t trigger any positive feedback either.) …Are we giving them life by not shining the spotlight more on the core of their argument?”

    It really helps to have a grasp of the big figures, to show just how pifflingly small is the human contribution, and how much evidence there is for living processes involved in maintaining homeostasis. But finding the figures and the science… they are scattered here like gold dust… and sometimes they seem questionable… for instance…

    Gary Gulrud, you said “Daily variance of CO2 measured by AIRS in mid-troposphere and at 10,000? at Mauna Loa is on the order of 10^1 ppm, this corresponds to a daily fluence between ocean and atmosphere of on the order of 100 Gtons!”

    But my calculations go thus: 380ppm CO2 in the air… http://www.grida.no/publications/vg/climate/page/3066.aspx shows a total atmopsheric CO2 weight of c. 750Gt. Maths: 380ppm=750Gt, thus 1ppm=~2Gt. Therefore you figure of 10ppm corresponds to 20Gt.

    I’ve put the figures as best I could, graphically, on my primer (link thru name). These figures were taken from places like Glassman’s and Anthoni’s websites, both of whom I have a high regard for, science-wise. But they are not infallible either. ALL CORRECTIONS WELCOME!

  105. Bob Cormack says:

    Joel Shore says:

    “I think that the idea that the two of you are missing is that different processes can dominate on different timescales. A given major volcanic eruption releases lots of particulates and not all that much CO2. However, the particulates wash out of the atmosphere relatively quickly (generally within days when they are ejected only into the troposphere and within months to a few years when they are ejected into the stratosphere). CO2, by contrast, stays in the atmosphere a long time.”

    The problem with that, Joel, is that all the actual evidence (as opposed to ad hoc theories created to support long lifetimes) shows that CO2 has a relatively short atmospheric lifetime. See, for example, the measured lifetime of radioactive CO2 after the 1964 atmospheric nuclear test ban took effect: http://cdiac.ornl.gov/trends/co2/well-gr.html

    Up until about 20 years ago, it was considered an established fact that CO2 had a 5-10 year lifetime in the atmosphere, established by a number of means. (See, for example, this short discussion:: http://www.financialpost.com/story.html?id=433b593b-6637-4a42-970b-bdef8947fa4e)

    Now, however, that would be a truly “inconvient truth”, as it would directly imply that Human-created CO2 (being created over 100 years) could only account for a few percent of the observed rise in concentration. Hence it has become necessary to promote, with a straight face, complicated theories, unsupported by any actual measurements, that “prove” a long lifetime for CO2. In general, those who promote these theories don’t attempt to explain what is wrong with the actual measurements of decades ago — they simply ignore them.

  106. Dee Norris says:

    @Bob Cormack:

    Didn’t you know that Gaia can selectively extract the radioactive CO2 from the atmosphere to help restore her natural balance? And that she is causing her mighty oceans to inject CO2 into the atmosphere just to rid herself of humanity who has spoiled her pristine environment?

    Gosh, you must be expecting proven physics and chemistry to rule. ;-)

  107. Bruce Cobb says:

    Joel Shore: Let’s say that for every 1 deg rise we cause in the temperature due to the direct effects of increasing CO2 levels…
    I’ll bet you thought you could sneak that one by. Nice try. Firstly, our contribution of C02 is small, only about 3% or so. Secondly, C02’s warming effect is logarithmic; by far, most of the limited warming effect (small, in comparison to water vapor) has already occurred.

  108. Daublin says:

    Joel, in your response to Dan Lee, you admirably try to give sensible reasons for addressing CO2 emissions, unlike Al Gore and others who–believe it or not–do talk about catastrophes more serious than famine and world war in a time frame of 100 years or even less.

    However, you talk right past Dan Lee’s much shorter argument.

    Dan Lee says:

    Finally, some perspective. An atmosphere that has remained stable enough to support the 3+ billion year evolution of life, through all these extremes, isn’t going suddenly spiral out-of-control into a life-baking oven when it hits 400 ppm of CO2.…If you take away atmospheric positive feedback, aren’t we done? End of show? Nothing left for AGW to stand on?

    You wrote: “(1) No serious scientist that I know of is claiming that there is a Venus-like instability and the climate is going to “spiral out-of-control into a life-baking oven” once CO2 levels hit 400ppm. The positive feedbacks just magnify the warming due to CO2 alone…They are not strong enough to lead to an instability. (On Venus they could because it is closer to the sun and hence receives more W/m^2 of solar energy.)”

    Joel, you are ignoring the broad point by discussing the details. This magnification you breeze by is what turns a 1-ish degree increase into a 5-ish one or more. Take a moment to really think about this. If a 1 degree increase was all we faced even at 5000 ppm of CO2, then that would take all the wind out of the sales of people saying we face doom if we don’t decrease CO2 emissions. Thus, the positive feedbacks are key. Do you care to address this, or dare I say, concede it?

  109. Bob Cormack says:

    Dee Norris: Are you saying that (gasp!) AGW is a religion?!

    Now that you’ve brought it up, I have noticed a strange similarity between the few “conversations” I’ve had about this subject on less friendly sites than this one and the types of interactions I’ve had with missionaries at my door ;-)

    (Except perhaps that missionaries, lacking the cover of anonymity, tend to be more polite.)

  110. Dee Norris says:

    @Bob Cormack:

    Didn’t impolite missionaries end up in the stew pot?

  111. Gary Gulrud says:

    Lucy, Bill: It is entirely credible that I’ve made an arithmetic error or used a value from the public domain inappropriately, but I believe this to be more likely than one of a logical/conceptual sort.

    My recollection is that the accepted weight of atmospheric C02 was 3000 Gtons, the surface vegetation 800 Gtons, oceanic dissolved CO2 50,000 Gtons and oceanic precipitate CO2 100,000 Gtons. I’ve seen in comments here recently, someone imply an atmospheric weight comparable to the biogenic weight which I discounted as an implausible typo.

    My impression is that the oceanic phytoplankton are tossed in to the oceanic dissolved total.

    I make no claim to precision; one source of inaccuracy on my part is to ignore in the daily variance a moderately hydrophylic nature of CO2 carrying it aloft during the day as the temperature rises. I do that because the Mauna Loa daily variance is larger than the AIRS factor and not the inverse.

    The central issue is that balanced equations, in the manner of chemical reactions, for the results of CO2 flux computations, are conceptually invalid predictin results. In chemistry we rigidly control inputs, solvent, temperature and pressure. This is not the case in nature in any way, shape, or form. They are valid only as a snap-shot of the present.

    Establishing the origin of the CO2 empirically is required for the assertion that it is of antropogenic origin in any genuine expression of fact. This would at present, require use of the 13C/12C fraction. Seuss naively supposed that since the 13C was increasing that this proved anthropogenesis. Unfortunately, he was mistaken, having ignored the temperature dependent oceanic partial-pressure of CO2.

    The inference that because total fluences of CO2 in nature are at any moment “in balance” therefore implies that a change composition of one sink or another can be assigned to a fluence of choice is false in principle and false in actuality. Truth and falsehood is not democratically resolved.

  112. johne37179 says:

    I grew up in Wisconsin and I want our glaciers back. A mere 12,000 years ago we had ice as thick as 5000 feet. Can you imagine the beer you could chill with that? I blame Al Gore for inventing global warming along with the Internet. To hell with all those paleoclimatologists and their interglacial periods. Never mind that we have gone through these cycles a couple of times before. I blame all those early Americans in North America back 12,000 years ago for driving all those SUVs.

  113. Joel Shore says:

    Bob Cormack says:

    The problem with that, Joel, is that all the actual evidence (as opposed to ad hoc theories created to support long lifetimes) shows that CO2 has a relatively short atmospheric lifetime. See, for example, the measured lifetime of radioactive CO2 after the 1964 atmospheric nuclear test ban took effect: http://cdiac.ornl.gov/trends/co2/well-gr.html

    The problems with that graph are:

    Bob

    (1) It doesn’t address the question of interest…which is not how long it takes a particular carbon atom to cycle out of the atmosphere but how long it takes a perturbation in the total atmospheric level of CO2 to decay. They are different things.

    (2) It is not obvious from that graph that the lifetime is what you claim it to be. As I noted, the decay of CO2 is simply not described well by a single lifetime…So, some fraction of a perturbation in the CO2 levels disappears quite quickly but there is also a long tail. Whether the long tail is there or not for what you have plotted can’t really be determined from what you showed.

    Bruce Cobb says:

    Firstly, our contribution of C02 is small, only about 3% or so. Secondly, C02’s warming effect is logarithmic; by far, most of the limited warming effect (small, in comparison to water vapor) has already occurred.

    If you don’t want to be taken seriously by any real scientist, I strongly suggest that you continue to repeat the 3% nonsense.

    As for its effect being logarithmic, what that means mathematically is that doubling the level from, say 280ppm to 560ppm will produce the same effect as doubling from 140ppm to 280ppm. (Your statement that most of its limited warming effect has already occurred is essentially incomprehensible. If you mean that the rise from 280ppm to 380ppm has already gotten you most of the warming from a doubling from 280ppm to 560ppm, you are demonstrably wrong…even neglecting the issues of the climate not having yet caught up to the current CO2 levels.)

    Daublin says:

    Joel, you are ignoring the broad point by discussing the details. This magnification you breeze by is what turns a 1-ish degree increase into a 5-ish one or more. Take a moment to really think about this. If a 1 degree increase was all we faced even at 5000 ppm of CO2, then that would take all the wind out of the sales of people saying we face doom if we don’t decrease CO2 emissions. Thus, the positive feedbacks are key. Do you care to address this, or dare I say, concede it?

    This is garbled to the point of incomprehensibility. You seem to be (among other things) confusing projections about future temperatures (which depend on how one assumes CO2 levels get) with estimates of the equilibrium climate sensitivity to a doubling of CO2. You are correct that in the absence of positive feedbacks, a doubling of CO2 should produce a bit over a 1 C temperature rise. However, raising CO2 to 5000ppm would be somewhere more than a 16X increase and would thus raise temperatures 4 C in the absence of feedbacks.

    And, the IPCC range for the likely equilibrium climate sensitivity is 2 to 4.5 C, not 5 or more. At any rate, I agree that the positive feedbacks are important (at least if we don’t allow the CO2 levels to get too out of hand–if we let them get up to 5000ppm for example, then we are screwed with or without the feedbacks). However, you can’t just wish them away and the current understanding of the paleoclimate seems to require them being there. In the case of the water vapor feedback and the ice-albedo feedback, they also follow from some pretty basic physics…and the water vapor feedback has observational confirmation from the work of Soden et al. among others.

  114. Gary Gulrud says:

    Lucy, I believe your site is using Carbon, or about 28% the weight of CO2.

    750 Gtons C == 3000 Gtons CO2. Otherwise, the figures I quoted do vary somewhat from the estimates at the link.

  115. Gary Gulrud says:

    “If you don’t want to be taken seriously by any real scientist, I strongly suggest that you continue to repeat the 3% nonsense.”

    Oh, boy, that proscription sends shiver’s up my spine. Ooh, I think I’m soiled.

  116. Bob Cormack says:

    Joel Shore says:
    )” (1) It doesn’t address the question of interest…which is not how long it takes a particular carbon atom to cycle out of the atmosphere but how long it takes a perturbation in the total atmospheric level of CO2 to decay. They are different things.
    (2) It is not obvious from that graph that the lifetime is what you claim it to be. As I noted, the decay of CO2 is simply not described well by a single lifetime…So, some fraction of a perturbation in the CO2 levels disappears quite quickly but there is also a long tail. Whether the long tail is there or not for what you have plotted can’t really be determined from what you showed.”

    First: You are ignoring the fact that C14 is continually formed in the upper atmosphere by cosmic ray bombardment. The graph shows the excess C14 injected by atmospheric A-bomb tests (the “perturbation”) decaying back to the natural background concentration. The “long tail” is simply the natural background concentration of C14. When you include this in the model, it is fit well by a single lifetime.
    Second: The graph demonstrates that there is a real-world process which removes ½ of all radioactive CO2 from the atmosphere every 10-15 years. While it is just possible that the removal process might run at a slightly different rate for C12 than C14, the difference can not be great, so it is reasonable to consider that the lifetime for ALL atmospheric CO2 is ~12 years.
    The graph also demonstrates exactly how long it takes a perturbation in CO2 levels to decay – since that is precisely what it is measuring. So, indeed, it does directly address your “question of interest”.
    This also means, that half of the the CO2 released this year by Human activity will be gone from the atmosphere in 12 years; as there is no way any physical mechanism can distinguish where a “particular” CO2 molecule comes from.
    I know it is fashionable over at RealClimate to yap about “long tails” and “multiple lifetimes”, but there is exactly NO evidence for any such phenomenon. The only thing that might partly save this theoretical House of Cards is the demonstration that the CO2 lifetime is a sensitive function of concentration. AGWers, however, have made NO attempts to make any such measurements – probably because measurements of CO2 lifetimes around 10-15 years (the probably outcome) would be, as I said, a highly “inconvenient fact”.

  117. Gary Gulrud says:

    Dr. S has alerted me, on another subsequent occasion, that my use of ‘variance’ above is inappropriate; should have been ‘variability’.

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