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Patrick 027 at 16:48 PM on 25 December 2008Arctic sea ice melt - natural or man-made?
I kinda lost me, too. Didn't mean to get so in depth in a summary... will truly wrap it up later... Tentative utline of what follows: barotropic refraction, reflection, instability, forced planetary waves Why the 1/R^2 stuff? Effect of stratification on otherwise barotropic waves compare baroclinic to barotropic waves The troposphere as a hologram (well, sort'a) --- NAO, AO/NAM, etc... -
Quietman at 09:07 AM on 25 December 2008Climate's changed before
And in follow up: "Nevle and Bird admit that volcanic activity and a decrease in the sun's intensity probably both played roles in triggering the Little Ice Age. Still, Bird said, human activity was undeniably important." http://www.msnbc.msn.com/id/28353083/ -
Quietman at 07:26 AM on 25 December 2008Models are unreliable
Dan Chris is a believer in equilibrium, a weird and non-existant concept. You see, without the concept of equilibrium, the entire AGW hypothesis comes apart. You might find this concept of interest: Letter abstract Nature Geoscience 2, 28 - 31 (2009) Published online: 14 December 2008 | doi:10.1038/ngeo388 Subject Categories: Atmospheric science | Climate science Age of stratospheric air unchanged within uncertainties over the past 30 years A. Engel1, T. Möbius1, H. Bönisch1, U. Schmidt1, R. Heinz2, I. Levin2, E. Atlas3, S. Aoki4, T. Nakazawa4, S. Sugawara5, F. Moore6, D. Hurst6, J. Elkins6, S. Schauffler7, A. Andrews6 & K. Boering8 "The rising abundances of greenhouse gases in the atmosphere is associated with an increase in radiative forcing that leads to warming of the troposphere, the lower portion of the Earth’s atmosphere, and cooling of the stratosphere above1. A secondary effect of increasing levels of greenhouse gases is a possible change in the stratospheric circulation2, 3, which could significantly affect chlorofluorocarbon lifetimes4, ozone levels5, 6 and the climate system more generally7. Model simulations have shown that the mean age of stratospheric air8 is a good indicator of the strength of the residual circulation9, and that this mean age is expected to decrease with rising levels of greenhouse gases in the atmosphere10. Here we use balloon-borne measurements of stratospheric trace gases over the past 30 years to derive the mean age of air from sulphur hexafluoride (SF6) and CO2 mixing ratios. In contrast to the models, these observations do not show a decrease in mean age with time. If models are to make valid predictions of future stratospheric ozone levels, and of the coupling between ozone and climate change, a correct description of stratospheric transport and possible changes in the transport pathways are necessary." An article referencing this paper: Does Global Warming Lead To A Change In Upper Atmospheric Transport? ScienceDaily (Dec. 24, 2008) — Most atmospheric models predict that the rate of transport of air from the troposphere to the above lying stratosphere should be increasing due to climate change. Surprisingly, Dr. Andreas Engel together with an international group of researchers has now found that this does not seem to be happening. On the contrary, it seems that the air air masses are moving more slowly than predicted. This could also imply that recovery of the ozone layer may be somewhat slower than predicted by state-of-the-art atmospheric climate models. -
chris at 02:18 AM on 25 December 2008Christmas cartoon on melting North Pole
John, Merry Christmas to you, and well done for maintaining a first class resource for addressing the salient topics of this fascinating and profoundly important issue. I've enjoyed reading your articles and has a wheeze posting here the past few months! and Merry XMas to everyone else ;-) -
Arkadiusz Semczyszak at 20:20 PM on 24 December 2008It's Urban Heat Island effect
You must to see, what said in Royal Netherlands Meteorological Institute (KNMI) about UHI http://www.agu.org/journals/eo/eo0851/2008EO510005.pdf. “… waste heat production…” not anthropogenic GHG making AGW… -
Arkadiusz Semczyszak at 20:11 PM on 24 December 2008Christmas cartoon on melting North Pole
Dear John Cook I have news for You: From the New York Times, December 12: Soviet scientists on board an icebreaker drifting just 300 miles from the North Pole have concluded that the world is getting hotter. Warm-water fish are appearing in increasing numbers in Arctic seas as temperatures have risen, melting the ice caps. The Russian explorers believe that very soon ships will be able to sail right ACROSS the Pole. This news appeared on December 12, 1938; he, he, he…Response: May I direct you to the skeptic arguments Climate's changed before and Arctic icemelt is a natural cycle. -
Philippe Chantreau at 11:53 AM on 24 December 2008Arctic sea ice melt - natural or man-made?
To get back on topic (sorry Patrick, you kinda lost me): Arctic sea ice extent growth came to a sudden stop and is now lower than 07. I'd have to verify, but it's likely to make it lower than any previous record for that time of the year. So far NSIDC shows a rather peculiar curve for this year's extent variation: very fast fall growth and now a winter halt. -
Quietman at 06:31 AM on 23 December 2008Global warming stopped in
1998,1995,2002,2007,2010, ????
But naturally, local observations are much better than instrument readings (it only took 30 years to catch up with what we all already knew). Next they can explain the cooler temps in southern CA. -
Quietman at 06:29 AM on 23 December 2008Global warming stopped in
1998,1995,2002,2007,2010, ????
"The Eastern U.S. Keeps Its Cool While The World Warms" ScienceDaily (Jan. 31, 2001) — Much of the Earth has warmed over the last half-century, but the eastern half of the United States has shown a cooling trend. NASA-funded research indicates cooler temperatures in the eastern U.S. are caused by an increase in sun-shielding clouds produced by warmer ocean temperatures in the Pacific. -
Olympus Mons at 01:05 AM on 23 December 2008The Mystery of the Vanishing Ocean Heat
Chris, If you make a comparison on blogs and sites and watch the behavior of both skeptics and believers it will stand out the bulling that the seconds resort to address the former. – It’s fascinating how Political you’ve became. Political in the sense that politics is not about convincing others, has never been! Politics is about making other behave in a certain manner, in spite of their believes! – Shame. :-) -
Wondering Aloud at 12:54 PM on 22 December 2008It's not bad
Well John after much reading I think this is a thread where you are likely wrong. I have read a lot of claims that CO2 increasing yields is a myth, however in controlled experiments it really tends to have a large positive effect. Some have even claimed that it doesn't work in the "Real World".. A good argument sometimes but one that doesn't work very well here. If CO2 increases yields under controlled conditions but this is not seen in the real world that would in fact strongly suggest that our readings of CO2 increasing were incorrect not that CO2 doesn't help. That would be an interesting thing to investigate. -
Wondering Aloud at 12:44 PM on 22 December 2008Does Urban Heat Island effect add to the global warming trend?
Could you please post a link to a copy of the actual method used to eliminate Urban Heat Island effect from the record? -
Wondering Aloud at 12:40 PM on 22 December 2008A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
Good point. I did like those books, I wonder why State of Fear rubbed me so wrong. -
jecht8 at 02:05 AM on 22 December 2008Arctic icemelt is a natural cycle
This whole piece is somewhat humorous. To even use arctic ice as evidence of a global warming trend as caused by CO2 over merely 3 decades of evidence is utterly ridiculous. Anthropogenic GW advocates will cite that the Northwest Passage has opened the for the first time since records began in 1978. Since records began. Sorry, but if a norweigan sailor by the name of Roald Amundsen could navigate the passage in 1906, then you're going to have to accumulate another century of evidence of so-called Anthropogenic Global Warming before the case is made. Remember people, satellite data is only available after satellites were invented... -
Kuni at 15:30 PM on 21 December 2008Antarctica is gaining ice
Increase in sea ice a bad thing http://www.slate.com/id/2192730/ . . . No one's entirely sure what's causing the expansion of sea ice in Antarctica, but the likeliest explanation is a disturbing one. According to a 2005 NASA-funded study, warmer temperatures have caused greater snowfall around the continent's edges, where the open oceans provide plenty of raw material for precipitation. (Warmer air absorbs moisture more readily.) The weight of that excess snow pushes sheets of sea ice down into the water, causing more water to freeze. The incremental expansion of Antarctica's sea ice has coincided with some more troubling changes. Four of the continent's largest glaciers (whose fates are largely unrelated to that of sea ice) are retreating rapidly, and researchers blame increases in ocean temperature. The diminishment of such massive glaciers means that, despite the slow creep forward of the continent's sea ice, the total mass of all Antarctic ice—which includes inland ice—has experienced a marked decrease. And a continuation of that trend could lead to significant rises in global sea levels. Furthermore, snow is melting much farther inland than ever, as well as high up in the Transantarctic Mountains. . . -
Quietman at 07:38 AM on 21 December 2008A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
WA That is what I meant by "somewhat alarmist" in my earlier comment. Many of his books were alarmist in nature but that is what fiction is all about. "Prey", the fear of nanotech; "Andromeda Strain" fear of the government; "Jurassic Park", fear of genetic engineering. "Eaters of the Dead" was a departure from alarmism for him but just as enjoyable. -
chris at 05:14 AM on 21 December 2008Empirical evidence for positive feedback
Re # 68 leebert, the pre-industrial atmospheric CO2 concentration was around 280 ppm, and we're at ~ 386 ppm. So we're only just over a third of the way towards doubling. Not 3/4's of the way! It's straightforward to calculate the temperature rise at equilibrium predicted from a rise of CO2 from 280 ppm to 386 ppm, assuming a climate sensitivity of 3 oC temperature rise per doubling of atmospheric CO2. This is near 1.4 oC. Since we're pumping CO2 into the atmosphere far faster than the earth can come to thermal equilibrium with the new forcing (from 386 ppm of CO2 and rising), we still have quite a bit of warming "in the pipeline" even if the atmospheric CO2 levels were to stop dead at 386 ppm. We've had around 0.8-0.9 oC of warming so far. We have another 0.5-0.6 oC in the pipeline. So the warming since the pre-industrial era is consistent with a climate sensitivity near 3 oC. One of the worrying things highlighted by Ramanathan is that the large mass of atmospheric man-made aerosols is protecting us somewhat from the full effect of our raised greenhouse gas levels. In other words we might have a bit more than 0.5-0.6 oC of warming "in the pipeline", which would indicate that the climate sensitivity is somewhat above 3 oC of warmning per CO2 doubling. As Ramanathan has argued, while it would be nice to rid the world of the brown cloud aerosol contribution which has a net warming effect, the total aerosol effect is a cooling one, and it's difficult to see how one could specifically eliminate brown clouds which tend to arise as a result of generalised aerosol formation. -
Wondering Aloud at 17:16 PM on 20 December 2008A Great Science Fiction Writer Passes - Goodbye Dr. Crichton
I really did not like State of Fear,to me in seemed paranoid. I have trouble believing characters who are knowingly and deliberately evil. Yes I know that some people have just the types of motives he presented but I have trouble believing stories that involve big conspiracies and secret government organizations. I read a lot of sci fi but this one I did not like. Stupid doesn't need a conspiracy it does fine working free lance. None the less he did many good things and I'm sorry he is gone. -
chris at 10:43 AM on 20 December 2008Models are unreliable
whoops....550 ppm should give a temp rise of 2.92 oC at equilibrium with a climate sensitivity of 3 oC per doubling of atmospheric CO2. -
chris at 10:37 AM on 20 December 2008Models are unreliable
It's really difficult to see your confusion Dan. For some reason you can't avoid linking a couple of straightforward truths together into a fallacious false premise. Incidentally, you didn't thank me for explaining the origin of your confusion over temperature transitions during glacial periods and their relationship to the insolation variations arising from out of phase elements of the earth's orbital properties. Anyway, it might help if we went away from the qualitative arguments that are scuppering your ability to create a logical progression, and looked at some numbers. Here are the two "truths" (i.e. conclusions strongly supported by real world evidence). Note that you got the first one wrong: (i) During ice age transitions, the temperature changes are driven by insolation changes resulting from Milankovitch cycles. During warming phases small amounts of CO2 are recruited from ocean and terrestrial stores and these amplify the Milankovitch-driven warming. The earth has a climate sensitivity near 3 oC of warming per doubled atmospheric CO2 as we know. (ii) During the present, atmospheric CO2 levels are racing upwards due to massive burning of fossil fuels sequestered for many 10's and 100's of millions of years underground. The rate of increase of atmospheric CO2 is more than 100 times faster than during ice age transitions (e.g. ~ 2.5 ppm per year now compared with < 2 ppm per 100 years during the last glacial to interglacial transition averaged over the period ~15,000 to ~10,000 ago). In each case the climate sensitivity is equivalent to around 3 oC of warming from raised CO2 levels per doubling of atmopsheric CO2. Let's look at the numbers. Since the earth's temperature has a logarithmic response to CO2 and the climate sensitivity is near 3 oC per doubling of atmospheric CO2 we can easily use some scientific graphing software with a straightforward log equation to determine the earth's temperature response at equilibrium resulting from the CO2 increases during the two circumstances (glacial to interglacial transition 15,000-10,000 years ago and the contemporary period): a. glacial to interglacial Atmospheric CO2 rose from ~180 ppm to ~270 ppm. This gives a temperature rise of ~ 1.8 oC at equilibrium based on a climate sensitivity of 3 oC per doubling. This is around the contribution to the temperature change during the glacial to interglacial transition arising from the increase in atmospheric CO2 and incorporates the feedbacks specific to the raised CO2 (the CO2 proportion of the water vapour and albedo feedback). b. Contemporary CO2 changes. Now the CO2 is being dumped straight into the atmosphere as a direct forcing. Its concentration change still results in a temperature response near 3 oC of warming per doubling. So far we've raised CO2 levels from 280 ppm to 386 ppm. Go back to our graph and read off the temperature change at equilibrium. This gives a temperature rise near 1.4 oC at equilibrium of which we've had around 0.8 oC so far. For contemporary warming the rate of CO2 increase is much faster that the earth can respond (i.e. come to temperature equilbrium), and so we still have a considerable amount of warming "in the pipeline", even if the CO2 levels were to stop dead at 386 ppm. We could look at the future. Atmospheric CO2 levels are rising at 2.5 ppm per year and still accelerating. Here's the temperature increase (over pre-industrial levels) that would result at equilibrium assuming we were to halt atmospheric CO2 concentrations at the following levels: we're at 386 ppm now: 1.4 oC above preindustrial levels at equilibrium 400 ppm 1.55 oC 450 ppm 2.05 oC 500 ppm 2.51 oC 550 ppm 2.88 oC 600 ppm 3.30 oC ...and so on.... -
chris at 09:39 AM on 20 December 2008Is Antarctic ice melting or growing?
It's about the real world WA. It's not about model studies in greenhouses and such like. I've cited a load of papers that assess real world effects in posts #7, #13 and #14. I think we'd all like to see some papers that you speak of. Why not give us some examples? This is a pretty serious subject. I don't think anyone is being "flippant". Can you point out the examples of "flippancy" too please? Incidentally, we came across the "Idso's" on this thread a couple of days ago (see posts #34 and #36): http://www.skepticalscience.com/What-does-CO2-lagging-temperature-mean.html they seem a rather disreputable, bunch with a tendency towards mendacity. Is that the same "Idso" you're talking off? -
Wondering Aloud at 08:42 AM on 20 December 2008It's the sun
Chris If you honestly think that the satellite record has bigger errors than the GISS I think you better take a look at www.wattsupwiththat.com There are thousands of "corrections" in the USHCN data which is best documented portion of the GISS record that are clearly incorrect. Resulting in a warming trend that is far larger than in the original data these corrctions range from undocummented to clearly incorrect. My viewpoint is astonishing to you because I started without a bias and applied the scientific method. As you frequently site papers where the authors appear unable to recopnize the concept of isolating the variable it is unsurprising that you are surprised by this method. -
Wondering Aloud at 08:32 AM on 20 December 2008It's the sun
I really want to know how at the current time these other external things especially orbital eccentricity compare to the past cycles in this current ice age. To me an amazing unanswered question is why are Greenland and Antarctica covered with ice? They certainly weren't this far into the last interglacial! Or as far as we know any of the interglacials. Why is the Earth so darn cold right now? -
Wondering Aloud at 08:27 AM on 20 December 2008Is Antarctic ice melting or growing?
I'm sorry I can't resist. From Chris above in #7 "And of course the notion that enhanced warming and raised CO2 levels is "good" for plant growth is also a fallacy when translated into the real world especially with respect to agricultural production." There are hundreds of reviewed and more importantly well done reproducible studies that show this increase you so flippantly dismiss. There is one group of plants that have evolved recently and have high tolerance to CO2 deprivation that show only modest gains with eleveated CO2. Others show consistently higher growth rates, yields and tolerence of dry conditions. Rather than citing hundreds I'll start with one name you would like to skip... Idso. You may not like it but the simple truth is they know how to do experimental design so their stuff tends to actually be science. It just clearly shows that your statement here was ...inaccurate. -
Dan Pangburn at 08:59 AM on 19 December 2008Models are unreliable
In post #80 Chris said “…the simple and obvious truth that significant insolation changes due to the slow cyclical orbital properties of the Earth, can result in temperature changes that result in slow drops in temperature in advance of changes in atmospheric CO2 concentrations…”. That is a fairly clear statement that Chris correctly perceives that atmospheric carbon dioxide level change did not cause average global temperature change during the last glacial period but in fact carbon dioxide level change lagged temperature change (the Middlebury site at post #41 gives links to the NOAA data that show this). In post #73 with the statement “We all know that the Earth's equilibrium temperature response has a logarithmic relationship to the atmospheric CO2 concentration” Chris appears to also correctly understand that added increments of carbon dioxide now have less influence on temperature compared to the influence on temperature that previous increments of the same size had when the atmospheric carbon dioxide level was lower and atmospheric carbon dioxide level did not drive temperature. But then Chris appears to ignore these correct perceptions and instead switches to the alarmist mantra that added atmospheric carbon dioxide now will cause a devastating increase in average global temperature. Perhaps Chris has abandoned logic and/or common sense as a result of becoming immersed in some of the products of group-think that he/she thinks passes for science. Or maybe he/she has simply become confused by the plethora of insignificant and/or irrelevant minutia. It will be interesting to find out just how cold the planet will need to get before the alarmists begin to realize that maybe they missed something. The rapidly growing number of scientists who recognize that it is a mistake to think that the planet will significantly warm because of increased atmospheric carbon dioxide may be an indication that this has already started to occur. It will probably take longer for the technologically incompetent politicians to relinquish their prosperity-diminishing control. -
Quietman at 08:30 AM on 19 December 2008Climate's changed before
Now THIS is interesting: Did Early Global Warming Divert A New Glacial Age? ScienceDaily (Dec. 18, 2008) — The common wisdom is that the invention of the steam engine and the advent of the coal-fueled industrial age marked the beginning of human influence on global climate. But gathering physical evidence, backed by powerful simulations on the world's most advanced computer climate models, is reshaping that view and lending strong support to the radical idea that human-induced climate change began not 200 years ago, but thousands of years ago with the onset of large-scale agriculture in Asia and extensive deforestation in Europe. ... http://www.sciencedaily.com/releases/2008/12/081217190433.htm -
Mizimi at 08:17 AM on 19 December 2008What does CO2 lagging temperature mean?
Not me Chris! PS: It was not 'my' article - nor did I say it was anything other than an interesting read. -
Mizimi at 08:10 AM on 19 December 2008Determining the long term solar trend
The amount of CO2 we put into the atmosphere is large when considered on its own. What remains there is about 50%, the rest ends up in the oceans. So of the 2.7 x10e13 kg we emit, roughly 1.3 x 10e13 stays to increase the 3 x 10e15 kg of CO2 already there. In that context the amount we add is small....very small. -
Quietman at 08:01 AM on 19 December 2008It's the sun
WA When I say it's the sun, I am generalizing. I see it as an engineering "root cause". Our orbit about the sun is a combination of the results of the sun in it's formation of the solar system. The combined gravitational effects of the system as a whole and the tectonic tides resultant. The effect of tectonics on the planets climate via changes to ocean circulation which in turn effect air circulation and control climate, added to the 8 minute charge cycle and irregularities in the solar wind and plasma forcing from sunspots. ie. a domino effect. -
chris at 06:07 AM on 19 December 2008What does CO2 lagging temperature mean?
Re #34 Yes it's interesting. It does quite a good job of pursuing a false argument and an excellent job of being fixed in time nearly 10 years out of date. Most of the article is about the lag of CO2 changes relative to temperature changes during ice age transitions. That's fine except the authors pursue the fallacious argument that because CO2 was a feedback response to solar insolation changes during ice ages, that CO2 variations can't drive temperature variations. They present this quite slyly as a "cause/effect" dichotomy....paraphrasing: "since CO2 changes were an effect during the ice age cycles and in pre-industrial times, they cannot be a cause now"! In fact some of the data they present merely reinforces the rather limited variation in atmospheric CO2 levels that occur under natural circumstances without catastrophic increases in CO2 (from massive tectonic events or terrestrial impacts, or massive burning of fossil fuels now), or very very slow drawdown of CO2 levels by weathering. E.g. they make a big play over the fact that the earth cooled a bit during the 2000 years from 7000-5000 years ago while atmospheric CO2 rose by 10 ppm. But 10 ppm over 2000 years (0.005 ppm per year) is 4 years worth at present rates of greenhouse gas emissions. That's around 4-500 times slower than the current increase in atmospheric CO2. A 10 ppm change over 2000 years is hardly going to affect climate, and clearly in a world with little variation in atmospheric CO2 levels, any climate variations must be dominated by other things (a small residual Milankovitch cycle affecting N. hemispheric insolation in this case I believe). It's unfortunate that the presentation is frozen in time around 2000. For example they present data by Pagani et al (1999) and Pearson and Palmer (1999) that appears to be "in conflict with greenhouse theories of climate change". But here's Pagani in 2005 showing that contrary to the assertions by the authors of your "article" that atmospheric CO2 was only 385 ppm in the middle Eocene, that the evidence indicates levels were actually 1000-1500 ppm, and in fact the slow, slow decline of CO2 levels through the Paleogene was likely the cause of ice sheet development and expansion in Antarctica. Pagani M (2005) "Marked decline in atmospheric carbon dioxide concentrations during the Paleogene" Science 309, 600-603 Abstract: The relation between the partial pressure of atmospheric carbon dioxide (pCO(2)) and Paleogene climate is poorly resolved. We used stable carbon isotopic values of di-unsaturated alkenones extracted from deep sea cores to reconstruct pCO(2) from the middle Eocene to the late Oligocene (similar to 45 to 25 million years ago). Our results demonstrate that pCO(2) ranged between 1000 to 1500 parts per million by volume in the middle to late Eocene, then decreased in several steps during the Oligocene, and reached modern levels by the latest Oligocene. The fall in pCO(2) likely allowed for a critical expansion of ice sheets on Antarctica and promoted conditions that forced the onset of terrestrial C-4 photosynthesis. Likewise Pagani has recently presented evidence that the ability of the Arctic and Antarctic to maintain ice sheets is effectively controlled by CO2 thresholds (< ~750 ppm for the Antarctic; <~ 280 ppm for the Arctic). DeConto RM et al (2008) Thresholds for Cenozoic bipolar glaciation Nature 455 652-655. and the role of CO2 levels in setting thresholds for glaciations is more widely suppoorted by the science: e.g.: Lunt DJ et al (2008) Late Pliocene Greenland glaciation controlled by a decline in atmospheric CO2 levels. Nature 454, 1102-1104 likewise recent data indicate that the relationship between climate and atmospheric CO2 levels in the Miocene are not so "chaotic" as the authors of your article would like us to believe: W. M. Kurschner et al (2008) “The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of the terrestrial ecosystem” Proc. Natl. Acad. Sci. USA 105, 499-453. ...and so on…. It seems the site you linked to is a nice little family business (Dad chairman, two sons are President and vice President and Mum is the "Operations Manager"!). Every page has a "Donate" button and no doubt they have such a nice time with everyone's donations they just don't have time investigate the literature properly or to keep their "info" up to date. I hope you left a donation Mizimi! -
Wondering Aloud at 02:24 AM on 19 December 2008It's the sun
Actually Quietman I'm not saying it is the sun, it might be, but it doesn't seem that's explaining things very well either. I think the sun is acting very weird compared to what I expected. I think uncertainty absolutely dwarfs the signal we are looking at, and every time I try to look at any indvidual piece of the puzzle it seems uncertainty grows. -
chris at 22:57 PM on 18 December 2008Water vapor is the most powerful greenhouse gas
re #45 It's all due to CO2-induced warming Mizimi.....at least none of it is due to "addition" by man (or ladies for that matter). Man can't "add" water vapour to the atmosphere. The atmospheric water vapour levels are essentially "defined" by the atmospheric temperature and pressure. We've already determined (see post #20) that the amount of water vapour released into the atmosphere by burning stuff, cooling towers and so on is a tiny proportion of the water vapour released into the atmosphere by the natural evaporative cycle (we calculated mankinds contribution is around 0.005% of that released by natural evaporation). What happens to all of that water (e.g the vast amount from natural evaporation)?. It all comes straight out as precipitation. What stays in the atmosphere is what the atmosphere can support in relation to the atmospheric temperature and pressure. In fact the research indicates that the atmosphere tends to maintain a relatively constant relative humidity (i.e. raised absolute humidity with increasing temperature and vice versa). In the paper[***] that Tom Dayton refers to (Tom links to an info summary), the water vapour levels increase right throughout the troposphere to the high altitude/low pressure regions. The authors note that as the atmospheric temperature fluctuates (e.g. the strongish La Nina cooling), so the atmospheric water vapour levels follows (such that a constant relative humidity is roughly maintained). Each of these observations is consistent with our understanding of the response of the atmospheric water vapour concentration to temperature, and its rather short term response to temperature changes (after Pinatubo the atmospheric water vapour levels dropped even ‘though we were still releasing water vapour into the atmosphere from cooling towers!), and is incompatible with the notion that mankind's emissions (a miniscule proportion of the natural evaporative contribution), can somehow affect the atmospheric water vapour levels. [***] A. E. Dessler et al (2008) Water-vapor climate feedback inferred from climate fluctuations, 2003–2008. Geophys. Res. Lett. 35, L20704, abstract: Between 2003 and 2008, the global-average surface temperature of the Earth varied by 0.6°C. We analyze here the response of tropospheric water vapor to these variations. Height-resolved measurements of specific humidity (q) and relative humidity (RH) are obtained from NASA's satellite-borne Atmospheric Infrared Sounder (AIRS). Over most of the troposphere, q increased with increasing global-average surface temperature, although some regions showed the opposite response. RH increased in some regions and decreased in others, with the global average remaining nearly constant at most altitudes. The water-vapor feedback implied by these observations is strongly positive, with an average magnitude of λq = 2.04 W/m2/K, similar to that simulated by climate models. The magnitude is similar to that obtained if the atmosphere maintained constant RH everywhere. I'm not totally convinced by the clouds snippet you linked to. Again reading the full paper[*****] a couple of things stand out: (i) the large proportion of those 124 stations are in S. Calif, along the Gulf coast and along the Eastern seaboard. So vast regions of the US aren't covered, and it's possible that a small rise in cloudiness in these built up regions may relate to their location in built up areas of the US (??). The authors acknowledge this: "Quantitative estimates of the uncertainties of the U.S. cloud trend during 1976–2004 shown in Fig. 8b are difficult to derive because of the poor coverage by the 124 military stations and the subjective nature of the human observations." and: "Although the 124 U.S. military stations provide useful data for total cloud amount up to the present, they have limited spatial coverage and are inadequate for monitoring regional trends in the western and other parts of the country." (ii) satellite data show a decreasing cloud trend during this period worldwide. So either the military station trend is a localized one..or isn't correct...or the satellite trend is incorrect...or the two series are measuring different things (e.g. low level clouds from ground observations vs high level clouds from satellites). I think one can quite reasonably be skeptical about drawing too many inferences from empirical cloud data so far. The main point of Dai and Trenberth's paper is that replacement of human cloud monitoring (as done in the military bases) by automatic monitoring systems, is a backwards step.. Note that although mankinds water vapour emissions don't have a significnat effect on greenhouse levels of atmospheric water vapour, we can probably influence the hydrological cycle by land use effects. and of course we are indirectly influencing the atmospheric water vapour levels by our CO2, methane, nitrous oxide emissions! [*****]Dai, A., T. R. Karl, B. Sun, and K. E. Trenberth, (2006) Recent trends in cloudiness over the United States: A tale of monitoring inadequacies. Bull. Amer. Meteor. Soc., 87, 597-606 -
chris at 22:26 PM on 18 December 2008Models are unreliable
You're not paying attention Dan. This was all explained to you in posts #78 and #80 above. Remember that the earth's orbital parameters are characterized by three major cycles having periods near 100,000 years, 41,000 years and 23,000 years. Since these cycles are out of phase a rather complex insolation pattern accrues from the "summation" of the cycles which matches the ice core data quite well. You'd benefit from reading this paper which describes some of the data in a manner that you could probably understand. Figure 2 is interesting; it illustrates the extraction of the earth's orbital cycles by Fourier transformation of ice core data on proxy temperature and 18O variations. The power spectrum shows clear strong peaks at 111,000, 41,000 and 23,000 years, which matches the orbital cycle frequencies rather well: Kawamura et al (2007) "Northern hemisphere forcing of climate cycles in Antarctica over the past 360,000 years" Nature 448, 912-919. You would also benefit from reading some of the papers John Cook discusses in his article on top of this thread. You shouldn't be frightened of the science Dan. Averting your eyes from scientific papers with schoolboy insults will only leave you woefully misinformed. -
chris at 09:52 AM on 18 December 2008Human CO2 is a tiny % of CO2 emissions
come on Mizimi, pay attention... My post #19 was very short and easily readable. Surely you can't have missed the phrase: "....apart from the glacial periods of the past few million years when atmospheric CO2 dropped towards 180 ppm." btw I made a tiny typo in post #19. "(around 20 million years)" should have read "(around 10 million years)" consistent with my post #13..... -
Quietman at 09:35 AM on 18 December 2008It's the sun
WA I agree it's the sun, just not TSI. Check out the recent articles about the magnetosphere and plasma discharges. Between gravitational stresses causing increased tectonic activity, plasma discharges and changes in heat and intensity of the plasma from sunspots are looking more and more like the culprit. Too bad the IPCC never looked into this part of the science. -
chris at 05:12 AM on 18 December 2008CO2 lags temperature
Goodness Dan, you are a master at contrived misunderstanding! This was all explained to you in posts #78 and #80 here: http://www.skepticalscience.com/climate-models.htm I have a horrible feeling that you're just ignoring the explanations and cited papers which essentially resolve your confusions. Let’s try again: ONE: The Milankovitch cycles do not only account for the major glacial <-> interglacial transitions. Remember that the earth’s orbital properties are characterized by three major cycles. Remember also that the three cycles [~100,000 year (eccentricity), 41,000 year (obliquity) and the 23,000 year (precession)], are out of phase. It’s not so difficult to understand that the interplay of these cycles gives multiple cyclical insolation changes that impact not only the major transitions, but the patterns of temperature variation within glacial and interglacial periods. That’s easy to see if one takes the parameters of delta-temperature or delta 18O from cores and Fourier transforms these with respect to time. Out pops as clear as day, strong peaks at frequencies at 111 kyr, 41 kyr and 23 kyr. Have a look at the paper I’ve recommended to you a couple of times now (Figure 2 shows the power spectra of delta 18O and delta T): Kawamura et al (2007) "Northern hemisphere forcing of climate cycles in Antarctica over the past 360,000 years" Nature 448, 912-919. You would also benefit from reading some of the papers John Cook discusses in his article on top of this thread: (Petit et al, 1999 and Shackleton, 2000 are useful) TWO: It’s been explained to you rather often now that our understanding of climate sensitivity (the earth’s temperature response to doubled atmospheric CO2) comes from a number of analysis of real world measurements. It doesn’t come from “computer use” whatever that might mean. Obviously GCM models are parameterized according to our knowledge of real world phenomena, so it wouldn’t be surprising if computer models were compatible with the climate sensitivity independently determined from analysis of the real world. You can read about the wealth of real world measurements that bear on this data here, for example: http://www.skepticalscience.com/climate-sensitivity.htm THREE: Poor Dan…reduced to telling porkies in para 4…how sad! Of course your logical fallacy that I highlighted in post #56 was the deceit that because ice age cycles weren’t driven by CO2 (CO2 amplified the response), that “added atmospheric CO2 today does not drive temperature”; that’s a grating example of the fallacy of the single cause. BTW, it’s good to see that you’ve dropped the fallacious “argument” that temperature downtrends with still highish CO2 levels doesn’t “prove that net positive feedback does not exist”. So you’ve learned one thing, which is admirable, and that’s really the value of boards like this. and you've had your “rational explanation” many times now (e.g. “ONE” just above in this post). FOUR: Your last paragraph is a delicious restatement of your fallacy of the single cause. it really isn’t difficult to understand Dan (I suspect you're just not trying!): (A) CO2 is a greenhouse gas. Raised atmospheric levels cause the earth to warm all else being equal. A large number of empirical (and theoretical) analyses indicate that the earth responds to raised CO2 with a warming near 3 oC per doubling of atmospheric CO2. (B) During ice age cycles the primary driver of temperature variations are Milankovitch cycles (see “ONE” just above). The warming is amplified by raised water vapour and raised atmospheric CO2 (see Mizimi’s post #57). The raised CO2 levels were small and extraordinarily slow – more than 100 times slower than the rate at which CO2 levels are rising now. The raised CO2 amplifies the Milankovitch warming and incidentally produces its own water vapour and albedo positive feedback. (C) Now the primary driver of temperature change is direct pumping of massive amounts of fossil fuel-derived CO2 into the atmosphere at a phenomenal rate. (D) Do you understand Dan? CO2 is a greenhouse gas. However it gets into the atmosphere it results in warming (all else being equal) equivalent to something around 3 oC per doubling of atmospheric CO2. -
Mizimi at 04:34 AM on 18 December 2008Human CO2 is a tiny % of CO2 emissions
The paleo temp record at http://www.climateaudit.org/?p=835 indicates SST's ranging over 5C for the past 1.3 million years during which time the CO2 level has been 'more or less' around 300ppm. Air temps would have ranged even further. How do we reconcile this? -
Mizimi at 04:20 AM on 18 December 2008Water vapor is the most powerful greenhouse gas
"a network of 124 U.S. military weather stations with continuous human observations provides useful information of total cloud cover averaged over the contiguous United States, and suggests an increasing trend (~1.4% of the sky covered per decade) in U.S. total cloud cover from 1976 to 2004, with increases over most of the country except the Northwest." http://www.tiimes.ucar.edu/highlights/fy06/dai.html Clear indication of increasing WV over the time period global warming has 'accelerated'. The question is, how much is due to man's additions and how much to CO2 induced warming? -
Dan Pangburn at 02:24 AM on 18 December 2008Models are unreliable
Here again you use a time period that includes the murky transitions from interglacial to glacial and glacial to interglacial instead of sticking to a period that excludes the transitions and the interglacials. Stick to the time period from about 110,000 ybp to about 20,000 ybp. Then the Milankovitch effect is very small but along with other factors still drives the temperature. The effect of the atmospheric carbon dioxide at that time must have been even smaller since it does not drive the temperature. We know that because the record shows that temperature trended down when the carbon dioxide level was higher than when the temperature was trending up. If you have a rational explanation that proves otherwise than give it. Your endlessly quoting fellow victims of group-think proves nothing. Oh, and in the world that I am in, there is 6% more arctic ice than last year, average global temperature in 2008 is the lowest this century and the atmospheric carbon dioxide level has increased since 2000 by about 14% of the total rise since the start of the industrial revolution. What world are you in? -
Dan Pangburn at 23:51 PM on 17 December 2008CO2 lags temperature
Chris claims to grasp that solar variation was the main cause of temperature variation during the last glacial period. That is, from about 110,000 ybp until about 20,000 ybp. That does not include periods of transition from glacial to interglacial or interglacial to glacial. He/she claims that CO2 is a greenhouse gas. Good. That has been well known for years. But then Chris loses it. The 3 C warming that he/she has stated repeatedly is a prediction of faulty computer use and Chris fallaciously states it as if it were fact. Apparently Chris is unable to come up with any rational explanation for how a temperature down trend could take place while the atmospheric carbon dioxide level was higher than it had been during a temperature uptrend as it did repeatedly during the last and previous glacial periods. Therefore he/she simply dismisses as a ‘logical fallacy’ that this proves that temperature was not driven by atmospheric carbon dioxide level at that time. That doesn’t cut it. Let’s hear the rational explanation. Elsewhere Chris has claimed to grasp that added increments of carbon dioxide have less influence on temperature when the atmospheric carbon dioxide level is higher than the same size increments do when the level is lower. Good. That also has been well known for years. But then Chris apparently fails to grasp that increased increments of atmospheric carbon dioxide level now have even less influence on climate than the same size increments did during the last glacial period when they did not drive temperature. -
chris at 23:17 PM on 17 December 2008CO2 lags temperature
Re #57 Pretty much. The lag may not be as much as that and there are clear hemispheric diferences in the onset of warming during glacial cycles. But yes, the Milankovitch warming is amplified by a rapid (essentially instantaneous) water vapour feedback. The CO2 comes from the deep oceans largely I believe. Note that increased plant growth reduces atmospheric CO2, so this should act against warming-induced recruitment of CO2 from terrestrial sinks. I think that the rising sea-levels innundate very larger areas of shallow continental margin and so that reduces plant biomass somewhat returning some CO2 to the atmosphere. But ocean sinks are the main source of enhanced CO2 during the warming phases of the glacial cycles I think... -
chris at 23:05 PM on 17 December 2008Models are unreliable
You keep repeating the same fallacious non-sequiters Dan without addressing straightforward critique. 1. Real world observations strongly support positive feedbacks to CO2-induced warming. We can measure the major feedback (enhanced water vapour) in the real world (see papers cited in my post #84), and recent work has reinforced the identification of the water vapour feedback and its quantitation: e.g. Dessler et al (2008), Water-vapor climate feedback inferred from climate fluctuations, 2003–2008, Geophys. Res. Lett., 35, L20704 for a layman's description see: http://www.nasa.gov/topics/earth/features/vapor_warming.html the identification and effects of the albedo feedback can be seen very clearly in the Arctic, and so on..So there’s no value in pretending that what exists doesn’t exist. 2. It’s rather well understood that the ice age cycles are driven by slow sinusoidal cycles in the earth’s orbital properties that alter the pattern of insolation. Sinc atmospheric CO2 levels respond very slowly to drops in global temperature (driven by Milankovitch cycles, for example), it’s not surprising that there is a significant lag between Milankovitch cooling and reduced CO2. Note that these CO2 changes in response to temperature during glacial cycles are rather small and extremely slow. They occur more than 100 times more slowly than the present rate of change in atmospheric CO2 resulting from massive burning of fossil fuels. It’s a logical fallacy to attempt the deceit that because CO2 variations weren’t the primary driver of temperature changes during ice age cycles (it amplified the changes of course), that massively increased atmospheric CO2 levels won’t increase the earth’s temperature under conditions of relatively stable insolation. 3. …and yes, we all know that the earth’s temperature varies as the logarithm of the atmospheric greenhouse gas concentrations. Welcome to the 19th century! This really has been known for more than 100 years. As we also all know, the earth’s temperature responds to enhanced atmospheric CO2 with somewhere near 3 oC of warming per doubling of atmospheric CO2. So yes, if we ramp up the atmospheric CO2 concentrations we expext that the world will warm. That’s also pretty consistent with real world observations. It's the greenhouse effect Dan! -
Dan Pangburn at 22:02 PM on 17 December 2008Models are unreliable
Actually a valid assessment of GCM predictions is fairly simple. But clear thinking might be prevented by the preconceived notion that increased atmospheric carbon dioxide is a significant cause of global warming. It might help to realize that the climate scientists who promote this notion did not need to learn about Dynamic System Analysis yet they impose substantial net positive feedback (feedback is a factor in Dynamic System Analysis) in their Global Climate Models which causes the models to predict significant global warming. Without the imposition of substantial net positive feedback the GCMs do not predict significant global warming. You can avoid being hoodwinked by the group-think bias of others by looking at the ‘raw’ data. First observe closely the temperature trends and carbon dioxide levels during the last glacial period (e.g. from 110,000 ybp to 20,000 ybp) as available on the web from NOAA. The data was extracted from proxies archived in the Vostok Antarctica ice cores. This is the same data that, in an unfocused view, was used in An Inconvenient Truth the substantially fictional movie that misled so many. A close look at this data exposes the mistake. The digital temperature data is available at http://cdiac.ornl.gov/ftp/trends/temp/vostok/vostok.1999.temp.dat and digital data for the Carbon dioxide levels from http://cdiac.ornl.gov/trends/co2/vostok.html . To facilitate the examination, this data is graphed as the second graph at the Middlebury web site given in post #41. If atmospheric carbon dioxide was a significant driver of average global temperature the temperature could not be in a declining trend when the atmospheric carbon dioxide level was higher that it had been when the temperature was in a rising trend. It is astounding that some supposedly cognitively competent people cannot seem to grasp this. Lacking any other knowledge one might think that if the atmospheric carbon dioxide level increases enough it may then significantly drive temperature. But when the carbon dioxide level is higher, increased increments of carbon dioxide have less influence than the same size increments had when the atmospheric carbon dioxide level was lower. Thus average global temperature was not significantly driven by atmospheric carbon dioxide level during the previous glacial period and atmospheric carbon dioxide level has even less influence on climate now. -
chris at 10:41 AM on 17 December 2008Models are unreliable
re #83 Remember that water vapour is a feedback. Its atmospheric concentration is a consequence of the atmospheric temperature (and pressure), and so the levels of water vapour respond largely to variations in the atmospheric temperature. These respond rather quickly (days-months), and so the atmospheric water vapour levels are near equilibrium with respect to the atmospheric temperature. So you can't add water vapour to the atmosphere in the manner that you suggest. Thus volcanic eruptions don't add water vapour (nor does evapo/transpiration)....in general they reduce water vapour. For example, after the 1991 Pinatubo eruption the atmospheric water vapour levels fell in response to reduced atmospheric temperature as a result of the cooling effect from the blasting of particulates high into the atmosphere and the reduction of solar irradiance at the surface [***]. So water vapour can never be a “primary forcing”. It’s quite well understood that the primary driver of the ice age cycles is the slow, slow sinusoidal variations in the earth’s orbital parameters (Milankovitch cycles). As the Milankovitch insolation takes the earth through a glacial to interglacial transition, the awesomely slow primary atmospheric warming is amplified essentially immediately by the water vapour positive feedback that occurs as a spontaneous response to atmospheric warming. This is further amplified by a slower responding CO2 feedback (which recruits its own enhanced water vapour as a positive feedback). The reverse happens during the waning phases of the Milankovitch cycles. Of course water vapour responds essentially passively to ANY forcing that results in a change in atmospheric temperature. Following volcanic eruptions the atmosphere cools and water vapour levels drop as observed [***]. And as the atmosphere warms under the forcing of massively enhanced greenhouse gas concentrations, so the atmospheric water vapour concentration response passively as a positive feedback. We can observe this in the real world too [*****]. [***] e.g. B. J. Soden et al. (2002) Global Cooling After the Eruption of Mount Pinatubo: A Test of Climate Feedback by Water Vapor. Science 296, 727-730. Abstract: The sensitivity of Earth's climate to an external radiative forcing depends critically on the response of water vapor. We use the global cooling and drying of the atmosphere that was observed after the eruption of Mount Pinatubo to test model predictions of the climate feedback from water vapor. Here, we first highlight the success of the model in reproducing the observed drying after the volcanic eruption. Then, by comparing model simulations with and without water vapor feedback, we demonstrate the importance of the atmospheric drying in amplifying the temperature change and show that, without the strong positive feedback from water vapor, the model is unable to reproduce the observed cooling. These results provide quantitative evidence of the reliability of water vapor feedback in current climate models, which is crucial to their use for global warming projections. [*****] e.g. Santer BD et al. (2007) Identification of human-induced changes in atmospheric moisture content. Proc. Natl. Acad. Sci. USA 104, 15248-15253 Soden BJ, et al (2005) The radiative signature of upper tropospheric moistening Science 310, 841-844. Gettelman A and Fu, Q. (2008) Observed and simulated upper-tropospheric water vapor feedback . J. Climate 21, 3282-3289 Buehler SA (2008) An upper tropospheric humidity data set from operational satellite microwave data. J. Geophys. Res. 113, art #D14110 Brogniez H and Pierrehumbert RT (2007) Intercomparison of tropical tropospheric humidity in GCMs with AMSU-B water vapor data. Geophys. Res. Lett. 34, art #L17912 -
Wondering Aloud at 06:01 AM on 17 December 2008It's the sun
Keep telling yourself... "it's warming rapidly... it's not the sun..." Meanwhile back on planet Earth. http://sohowww.nascom.nasa.gov/data/realtime/mdi_igr/512/ Worst part about all of this is there should be a big lag before any noticeable cooling. In other words this winter should be warm based both on AGW and "it's the sun" theories. Anyone who thinks it is warm this winter is either very lucky or needs professional help. We need about +30C the rest of the year to get back up to average. At present we are about 55 C low on that. Please don't tell me it's warm in Europe (record snow falls) or Siberia (-60) that makes up for it. Spring was 3 weeks late of average and hard freeze was one month early. A couple more years of warming like 2007 and 2008 and you are going to see famine in the United States. Our local Ag reporter told us harvests were off 15% from predicted in the US this year because of low temperatures. -
Wondering Aloud at 05:51 AM on 17 December 2008What does CO2 lagging temperature mean?
When all is said and done, the Temperature goes up first than the CO2 in all of the ice core records and the cave records as well. That means CO2 cannot be the driver of the climate in the pastrecord. LeChatlier's principal can then explain the swings in CO2 levels. In other words warming clearly causes CO2 to increase. The fact that a hypothetical mechanism can be proposed that the CO2 increases the warming doesn't alter the underlying fact that the past record does not tell us that CO2 causes warming. It may or may not cause warming, I had thought it certainly would, but the more I learn the less certain I am. In the past it was not a significant driver of climate despite much wilder concentration swings than we are likely to see. I also can't see how one can look at the record and suggest warming if it happens and CO2 increase when it happens would not be a net benefit to the biosphere. -
Mizimi at 05:49 AM on 17 December 2008It's cosmic rays
A thought: cosmic rays are essentially protons, alpha and beta particles (90%,9%,1%) and since it is well known that both alpha and beta particles cause condensation trails in cloud chambers thro' ionisation, does it not follow that in appropriate atmospheric conditions they would cause condensation nuclei to form? And that the extent of such formation would depend on the quantity and energy levels of these particles? Also, is the ratio of particles always the same or is there variation which would allow for increased/decreased cloud formation regardless of the overall level of CR's? -
Wondering Aloud at 05:36 AM on 17 December 2008Latest satellite data on Greenland mass change
While it isn't a big deal this statement "The rate is also increasing over time, suggesting an acceleration of mass loss." does not appear to be correct. (See below link) In addition I have wonderful video of our NASA friends telling us that the Maldives etc. would vanish by the year 2000. None of these claims made over the last 20 years appear one bit closer to coming true. Indeed in every specific instance they used sea level is down or land area is up. (Bangladesh) Maybe we should lay off this kind of claim. http://wattsupwiththat.com/2008/12/05/satellite-derived-sea-level-updated-trend-has-been-shrinking-since-2005/ I recently saw a paper using the original data as opposed to the "corrected" data on sea ice extent that claimed it had been increasing over the last 30 years. I didn't buy that as significant either but it was far more convincing than the minipulated pseudo data we see too often. -
Mizimi at 05:29 AM on 17 December 2008CO2 lags temperature
CO2 lags warming by 800 -1000 years, therefore warming is initiated by increased TSI ( whether M cycles or sun activity is moot). That would increase WV which re-inforces the initial warming and temps begin to rise, releasing CO2 from open water and from increased plant growth. No? -
Mizimi at 05:17 AM on 17 December 2008We're heading into an ice age
QM: Yes, and it makes rather a nonsense of trying to assign mean sea level deviations to global warming. The Isles of Scilly is a group of around 50 islands some 45km south west of Cornwall, England. They have been inhabited since (at least) the bronze age, some 4000ya. At low tide, stone houses, roads and field perimeters are revealed, dating from that time, so either msl has risen a few metres in 4000yrs or the islands have sunk.....how to tell the difference?
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