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Mizimi at 02:57 AM on 2 January 2009It's not bad
#14....Most of the examples of increased CO2 giving increased plant growth have come from environments where the CO2 level is artificially held at around 1000ppm. In the real world the levels have risen from around 260ppm (1000AD) through 290ppm (1900AD) to 380ppm (2005), in other words the increase over the period we have started taking interest in what's going on is at best 100ppm. Roughly, doubling the level gives a 50% increase in growth, so adding a third (real world) isn't going to show up much at the small scale level. Globally, however, the increase may be significant, although probably unquantifiable -
Mizimi at 02:45 AM on 2 January 2009Models are unreliable
Between 1970 & 2000, CO2 levels rose from 324ppm to 368ppm with a decadal increase of around 4~4.5%. (1970~324, 1980~337, 1990~353, 2000~368) The GISS data shows a decadal increase in GMT of 0.17C over the same period, ie. GMT rose 0.51C during those 30 years.(15% of that 3C doubling) But the CO2 level rose 14.8% in the same period (48ppm) So what happened to the logarithmic progression? Also, in 1800 the GMT was between -0.5 to -0.8C below GMT in 2000: The CO2 level in 1800 was 280ppm and in 2000 was 368...an increase of 67% that yielded a rise in GMT of less than 1C. -
Risky at 15:09 PM on 1 January 2009There is no consensus
Re: post #94 - 'Assinine comparison': how so? It may be an oversimplification to describe anthropogenic climate change as a house fire and cuts to emissions as insurance, but with odds like this, would you go on with business as usual, or might you be inclined to make changes at reasonable cost, ahead of absolute certainty? Re: post #94: add geopolitical stability to the list of spin-off benefits. No need for a war for oil. -
Quietman at 11:47 AM on 1 January 2009Latest satellite data on Greenland mass change
WA Philippe was kind enough to give me these links in the Arctic Ice loss thread: http://nsidc.org/ http://nsidc.org/data/seaice_index/ They show a good map of the polar region and the anomalies. Also Philippes recent comments there are of interest. -
NewYorkJ at 10:32 AM on 1 January 2009There is no consensus
#93 They are called "deniers" when they resort to the type of tactics described in Dr. Holdren's op-ed, the clearly dishonest APS spin described above, repeatedly making multiple dubious claims as catalogued nicely on this website (while arrogantly and falsely asserting it "disproves" AGW and promoting their claims to any willing media outlet), calling global warming a "hoax", or calling the overwhelming majority of climate scientists "alarmists" because they don't like the implications of the science. Holdren makes the distinction between "skeptic" and "denier". Every scientist is a skeptic so that doesn't say much. "Denier" might be to harsh. I'd settle for "contrarian". A comment from another scientist on this issue: “They argue not as scientists but as lawyers. When they argue, they pick one piece of the fabric of evidence and blow it up all out of proportion…Their purpose is to confuse.” - Pieter Tans #94 You're right. It's conservatively more like 90%-95%. Personally, I thought it was time to act when IPCC2 presented the "more likely than not" conclusion regarding "most of the observed warming" before moving on to "likely" and "very likely". Of course, mitigating actions carry their own risk. If we decided to cut emissions 95% in 5 years, it would very likely cause severe economic damage. However, every objective economic study on mitigation proposals made so far suggest relatively affordable net economic costs in comparison with the risks this century (even the relatively conservative estimates) if we don't act. A few studies result in net gains - and most studies don't consider the economic benefits of decreased reliance on foreign fossil fuels and some of the avoided massive economic costs of climate change. Thus, it's ironic that those preaching gloom and doom on the economy call many scientists "alarmists". -
Philippe Chantreau at 07:58 AM on 1 January 2009Arctic sea ice melt - natural or man-made?
Let me clarify one thing: in my definition, a scientist is someone who is an expert in a field (usually that implies an advanced degree in that field or a closely related one), does research (i.e. publishes papers in peer-reviewed science journals) and whose work is of significant interest to others doing research in that field (i.e. cited, used in other publications). If that's you, then you're a scientist. If not, then you're not one by that definition, and I like that definition, that's the one I use. You said that you were doing applied science. That's vague. A pilot does applied physics and engineering, that does not make him a physicist or aeronautical engineer. The noconsensus graph is not referenced, I have no idea where it comes from. Is area really more important than extent and volume (this latter being certainly the most important)? The Antarctic mass balance graph has no legend and it really needs one; still, it's unclear at first glance whether there is a net gain or loss, I see sizeable areas in the graph with the rectangles showing considerable negative gain (loss?). At my level, I find NSIDC and Cryosphere Today much more useful: http://nsidc.org/sotc/sea_ice.html http://www.nsidc.org/data/seaice_index/ This graph shows a statistically significant decline in global sea ice: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg This does not show much of a TREND in Antarctic sea ice anomaly: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.south.jpg Unlike the TREND shown here for Arctic sea ice: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.jpg Quote from NSIDC, from the Arctic and Antarctic standardized anomalies and trends Jan 1979 Dec 2007 graph: "The Antarctic ice extent increases were smaller in magnitude than the Arctic decreases, and some regions of the Antarctic experienced strong declining trends in sea ice extent." The noise in the Antarctic is larger because of a much stronger seasonal variation. " -
Quietman at 06:16 AM on 1 January 2009There is no consensus
Re: "If there was only a 20% chance of your house burning down, would you go without insurance?" Assinine comparison. -
Quietman at 06:14 AM on 1 January 2009There is no consensus
Holdren, like Hansen, is a known alarmist. These are the people that call skeptics deniers. In science you propose a hypothesis and test that hypothesis in a manner that other scientists can reproduce. You DO NOT call the other scientists that disagree with you "deniers" because they happen to disagree, especially when they provide evidence to disprove your hypothesis. -
Arkadiusz Semczyszak at 22:26 PM on 31 December 2008Arctic sea ice melt - natural or man-made?
Philippe Chantreau - sorry my popularizing (You so, probably think that I’m not "scientist"?) publications are in a ”beautiful” (very difficult too), polish language - on-line, for example only one: http://192.168.0.11/download/technologia/efekt_szklarni.pdf. I propose You this page about “ice”: http://noconsensus.files.wordpress.com/2008/12/global-sea-ice-area-variation-bootstrap-algorithm1.jpg?w=667&h=455 (- do not have decreasing sea ice at the last 30 years?) and http://www.unep.org/geo/geo_ice/images/full/6a_antarcticamassbal.png - for a complete image about “The global ice story”. …and may dear “Interlocutors” (hi, hi, hi…) Happy New Years everybody!!! -
NewYorkJ at 06:15 AM on 31 December 2008There is no consensus
#88: Exactly right. I don't have a problem with a few skeptics stating their opinion. I do have a problem, however, with gross distortions and dishonest rhetoric. In this case, a single APS member and editor of one of their many non-peer-reviewed newsletters decided to post his opinion and some material. It gets widely reported among the denialsphere as "The American Physical Society, an organization representing nearly 50,000 physicists, has reversed its stance on climate change". There is a clear and concerted effort to blow every fabric of data well out of proportion, whether it's of scientific nature or in this case, activities of an APS member. This is the reason why many climatologists don't have a lot of respect for the arguments from many of those who call themselves climate "skeptics". Dr. John Holdren (recently selected as Obama's science advisor), describes it best. He had a good op-ed piece earlier this year with an even better follow-up. http://gristmill.grist.org/story/2008/12/22/12217/584 -
Olympus Mons at 04:04 AM on 30 December 2008Climate change on Mars
Problably wrongly, but I had the impression that this website was sort of impartial in assesment. But not mentioning in this thread the real reason why some people started to associate the two events, which is: THE SHRINKAGE OF HE MARTIAN NORTH POLE, really takes me aback. Does any one knows how that is going? -- for years, since mid 90 I've read that Mars pole was diminishing: Does anybody knows how that is now? Is it following the sun and started do grow again or not?! -
Risky at 23:20 PM on 29 December 2008There is no consensus
Re: Post #77 from Austerlitz - if you pin your hopes on 'skeptics' like David Evans, maybe you should see this article (by David Evans) posted on the Lavoisier Group website (Australian 'skeptics' org with links to the coal industry, among others). http://www.lavoisier.com.au/articles/greenhouse-science/climate-change/evansd2007-12.php See the 5th from last paragraph, starting 'I emphasise that we are making a bet...'. Evans estimates that the likelihood that CO2 emissions are the dominant cause of global warming is only 20%, not 90% as per the IPCC estimate. Note the wording - 'dominant' cause. I understand Richard Lindzen is now also similarly lukewarm on the odds. Maybe others could confirm. If there was only a 20% chance of your house burning down, would you go without insurance? With skeptics like that, who needs believers? P.S. I am not a scientist (published or otherwise), but a risk management professional. I am curious as to what the risk appetite of those participating in the global warming debate is - just how much risk of dangerous climate change is acceptable? -
Philippe Chantreau at 06:06 AM on 27 December 2008Christmas cartoon on melting North Pole
Happy Holidays (a little late, sorry) and thanks for keeping up a great site John :-) -
Philippe Chantreau at 06:05 AM on 27 December 2008Arctic sea ice melt - natural or man-made?
From what I read so far, there is some unusual weather in the Arctic that had 2 effects: compacting the ice together (thereby reducing the total extent) and keeping the air much warmer than normal. Neither seemed to have been expected by the people studying the SI. Good luck with the shoveling, hope the winter kills off those bark beetles. We had over 15 inches down in the PDX area, and they're just not used to it here! Of course now it's turned to slush and the roads are nasty. Happy Holidays! -
chris at 00:08 AM on 27 December 2008The Mystery of the Vanishing Ocean Heat
Olympus Mons, pointing out the facts isn't being political is it? It's the propagating of well-recognised falsehoods that's "political". So HS asserts that the IPCC collected data from Hong Kong to "prove" sea level is rising. I pointed out that the IPCC don't collect data, they "collate" scientific data and summarize this in reports, and that in any case it's well understood how sea level data is collected and analyzed, and I gave some sources that can be accessed to understand this. HS seems to think that pointing out the facts constitutes "being on my high horse", and confesses that he got this piece of misinformation from a newspaper interview. Who's being "political" there OM? The one who points out the facts? or the two that assert stuff in a newspaper interview that isn't true, and propagate this without making an effort to establish the facts? As for your "skeptics" and "believers", are you implying that a "skeptic" is someone that tells/propagates untruths and a "believer" is someone that makes an effort to establish scientific veracity? I would have thought in this instance that HS is a "believer" (accepting untruths because it fits with his agenda/worldview or whatever) and I'm being a "skeptic" (making an effort to establish the reality behind what is very clearly a misrepresentation). shame indeed! ;-) -
chris at 23:52 PM on 26 December 2008Models are unreliable
surely not! Are you really suggesting that "equilibrium is a weird and non-existant concept?" There isn't a quality more fundamental to the natural world than "equilibrium" Quietman. Let me give you a simple example. You've been away on a trip during the winter. You come back to your chilly house left without any heat on. You turn on the heating and set the thermostat to 18oC. What happens? Does the house temperature instantaneously become 18oC? Not really. And when the temperature eventually reaches 18 oC what's going on? I think you'll find that the temperature in your house has settled at an equilibrium temperature of 18 oC as a result of a balance between warming from your radiators and heat loss to the surrounds. When you switched on your heating the house temperature was far from the equilibrium temperature you defined with your thermostat, and as it became closer and closer to 18 oC it became closer to equilibrium. Your heater transported the temperature of your house from one equilibrium temperature (in which the temperature was in or near equilibrium with the surrounds) to another equilibrium temperature (in which the rate of heat input and loss is in equilibrium). -
Quietman at 13:13 PM on 26 December 2008Arctic sea ice melt - natural or man-made?
Philippe Thanks. That is a useful site, better view of the polar caps. The anomally is still exactly where I expected to see it again, I just wanted to confirm it. I have not read all 365 posts. I was busy in the summer, which is why I have not been posting as often also. Unfortunately this is a bad winter and I have been doing a lot of snow removal, salting and sanding since October, so not much time now either. -
John Cross at 02:12 AM on 26 December 2008Christmas cartoon on melting North Pole
John: My daughter and I loved the cartoon. Merry Christmas to you and all your readers. We wish you all the best in the new year and look forward to more of the same quality posts we've come to expect ;-) Regards, John -
Philippe Chantreau at 20:59 PM on 25 December 2008Arctic sea ice melt - natural or man-made?
Quietman it is hard for me to believe that, after a 360+ posts discussion of Arctic sea ice, you're not familiar with the National Snow and Ice data Center. I linked it several times earlier when WA was appealing to Watts blog and suggesting that the up trend in Antarctic SI was significant whereas the down trend in Arctic was not. A look at these will inform you on that: http://nsidc.org/ http://nsidc.org/data/seaice_index/ -
Quietman at 19:53 PM on 25 December 2008It's not bad
Lets look at this from a logical perspective. Warmer means more like the world that we evolved in during the PETM (when prosimians first appear) in Asia. Colder means more like the world that came close to driving us to extinction (glacial maximum) in Africa. We are from a tropical paradise, no polar ice caps and green pole to pole. Which do we wan't for our offspring? Warm and abundant or cold and starvation? -
Quietman at 19:44 PM on 25 December 2008Arctic sea ice melt - natural or man-made?
Philippe Interesting, albeit not totally unexpected. NSIDC? Not familiar, can you post a link? Patrick You lost me again as well. Maybe leave out the calculations and proof and go right to the summary? -
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.
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