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scaddenp at 08:02 AM on 15 June 2011Examining Dr. John Christy's Global Warming Skepticism
KL - thanks for pointing that out! Hugely entertaining. I can't wait for Gilbert's next post. Grab a textbook and follow it through. -
CBDunkerson at 07:55 AM on 15 June 2011The greenhouse effect is real: here's why
Great discussion folks. I thought I had a pretty good grasp on greenhouse warming 'fingerprints'... but obviously there is alot more complexity to the issue than I thought. Thanks for the info. -
Tsumetai at 07:50 AM on 15 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Is there an online updated link to 60 month and 132 month running averages of the global temperature?
That's what Wood for Trees is for. -
Pete Dunkelberg at 07:43 AM on 15 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Pick up sticks.
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Eric the Red at 07:39 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Let me get this straight Sphaerica. It may well be that the temperature is lower in 2030 than 2010, but it is not appropriate to call it cooling, or lack of warming, but delayed warming or hidden warming is okay? Talk about nitpicking. It certainly appears that any presentation that does not exemplify your own beliefs, you label as "misinformation." Oscillation only "masks" the warming when it is in the cooling phase. During the warming phase, it is enhancing the warming. One cannot accept the premise of decadal oscillation resulting in cooling without also accepting its role in warming. -
Albatross at 07:37 AM on 15 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Pete @67, Re the running averages-- not to my knowledge. If someone knows please share. Thanks :) I was planning on emailing Hansen and asking them to include that as one of their regular monthly graphics. -
jonicol at 07:31 AM on 15 June 2011Examining Dr. John Christy's Global Warming Skepticism
KR - Thanks for your apology which is acknowledged and accepted. The Australian Climate Science Coalition, though, is not in any way connected to the AEF or to the IPA. It was introduced at an AEF Conference in Canberra, simply because of the timing of its formation which coincided with an Annual Conference of AEF and there members of AEF who are also in our ACSC, but I am not aware of who they are. I am not a member of AEF nor of IPA. The ACSC is funded privately by a benefactor from New Zealand and as far as I am aware, the ACSC has NO funding connection directly or indirectly with any other body. For this reason we run a very tight budget with a website which picks up material from voluntary individuals. -
Pete Dunkelberg at 07:21 AM on 15 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
Recall Uncertainty, noise and the art of model-data comparison. Is there an online updated link to 60 month and 132 month running averages of the global temperature? -
Albatross at 07:07 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Sphaerica @28, Sigh-- I agree with your coments about the post @27. Eric @27 directs us to slide 3 of Latif's 2009 WCC3 talk and neglects to mention that the figure in question is not in fact an official prediction, it is essentially fictitious, a cartoon. Dr. Latif presented that slide, which depicted a hypothetical temperature trace in which random internal climate variability was superimposed on a monotonic increasing temperature curve. When speaking to this slide/cartoon Dr. Latif said: "It may well happen that we enter a decade, or maybe even two-you know- when the temperature cools, alright- relevant to the present level, alright, and then, I know what is going to happen I will get millions of phone calls you know saying "what is going on, so is global warming disappearing". You know. Have you lied on us". You know, so, and therefore this is to me why we need to tackle this decadal variability prediction issue". Had the 'skeptics' here actually taken the time to listen to Latif's talk he would have known that. And again, so far the Keenlyside forecast has been a bust. I request that the moderators please consider snipping that piece of blatant misinformation (the link to wcc3 and associated text) @27-- I'm sure that SkS does not wish to assist in the distribution of confusion and misinformation. And while we fiddle Rome prepares to burn. -
Bob Lacatena at 06:49 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
27, Eric the Red, For emphasis, let me repeat 3 main points about Latif and Keenlyside:- The work of Dr. Latif and Dr. Keenlyside in Nature “does not allow one to make any inferences about anthropogenic global warming.” (Latif's own words).
- Their work has no forecasting skill after 2015. “We don’t trust our forecast beyond 2015.” (Latif's own words).
- Dr. Latif is not making any predictions about what will happen after 2015 other than that the long-term temperature warming trend driven by anthropogenic GHGs will continue and that the near-term temperature trend must catch up with the long-term trend, likely during a period of rapid warming.
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Bob Lacatena at 06:38 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
27, Eric the Red, Your disinformation is, once again, clear evidence of denial. The entire Latif-says-the-globe-will-cool meme has been done to death. It's ancient history... and you are representing a serious falsehood in all of your statements about his position. His words:“I don’t know what to do. They just make these things up.”
Read more here. And stop spreading lies. [The easiest way to start is to stop getting your misinformation from WUWT.]...but at least get the data correct.
Hmmmph. Yeah, the data, and the interpretation, and who says what, and all the rest. Physician, deny thyself! -
Anne-Marie Blackburn at 06:35 AM on 15 June 2011Climate change is real: an open letter from the scientific community
Great letter - look forward to reading their exposés of how contrarians operate. If this letter's anything to go by, it should be a great read. -
Eric the Red at 06:11 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Chris, That is why I quoted both "cooling" and "lack of warming." Figure 4 to which you referenced was an older graph. His most recent presentation in Geneva, 2009 shows three decades of cooling or a lack of warming until 2030, then continued warming. It looks more like Latif predicts the warming to start around 1930, rather than centered around it, leaving about two more decades of a "lack of warming." ( -Link to disinformation site snipped- ) If the decadal oscillation results in insignificant warming, then the Earth will be a lot warmer by 2030. If the predictions hold true, as predicted by Latf, et. al., then temperatures will be similar (or cooler) in 2030 to 2010. I have no problem with you taking a dig at me, but at least get the data correct.Response:[DB] Link to disinformation site snipped. Advice: In the spirit of getting things correct, stick to reputable sources.
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les at 06:10 AM on 15 June 2011The Planetary Greenhouse Engine Revisited
5 - Badgersouth Sometimes this site really needs a "like" button :-D -
dana1981 at 06:00 AM on 15 June 2011Climate change is real: an open letter from the scientific community
This is an excellent letter - harsh, but true. I like how they didn't pull any punches. The whole series should be interesting. -
les at 06:00 AM on 15 June 2011The greenhouse effect is real: here's why
22 - paddy; leaving science to one side and concentrating on English comprehension, may I draw your attention to the top of the page "Reposted from The Conversation." This is not a SkS science article I'm not going to paraphrase your "need to do better" words as that would just be obvious and tacky. -
John Hartz at 05:56 AM on 15 June 2011The Planetary Greenhouse Engine Revisited
My one-line repsonse to climate denial bloggers who post about the Venusian atmosphere: "What happens on Venus, stays on Venus!" -
Albatross at 05:43 AM on 15 June 2011The greenhouse effect is real: here's why
Patrick @22, Your weeping dismissal of the alleged absence of science are quite ironic given that your post contains no science whatsoever, never mind any attempt to substantiate your position. Indeed, you need to do much better on a science site. -
John Hartz at 05:29 AM on 15 June 2011The Planetary Greenhouse Engine Revisited
Kudos on an excellent post. -
Patrick Kelly at 05:17 AM on 15 June 2011The greenhouse effect is real: here's why
I must say that I find this article to be a very disappointing addition to a site that headlines itself as Science based. Long on assertion and ambitious in conclusions which stem from very little solid scientific argument. Need to do better. -
angliss at 04:59 AM on 15 June 2011The Planetary Greenhouse Engine Revisited
Thanks! -
Chris Colose at 04:56 AM on 15 June 2011The Planetary Greenhouse Engine Revisited
I hadn't seen this before but I just added it to the Recommended reading -
Albatross at 04:52 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Hi Chris, Re your #25. Sorry if I was not clear-- my dig was at Eric, not you-- I very much appreciate you clarifying the Keenlyside et al. issue :) I concur with you that the Earth will be quite a bit warmer by 2030. -
angliss at 04:51 AM on 15 June 2011The Planetary Greenhouse Engine Revisited
Hopefully no-one's offended by this self-promotion, but I did a five-day series of posts that took apart common denier arguments for how Venus could be kept hot by means other than the greenhouse effect. This link goes to the first of the series. -
Bob Lacatena at 04:27 AM on 15 June 2011The greenhouse effect is real: here's why
I'd like to point out another minor inconsistency in the fingerprints. The idea that winters and nights will warm more than summers and days, while true, should also apply to a lesser degree to any forcing, since many of the primary feedbacks are themselves greenhouse gases (mostly H2O). At the same time, part of the overall feedbacks for even an initial GHG forcing include changes in albedo, which would not bear the same signature. So while a pure GHG increase from CO2 now will involve a larger degree of difference, it could be difficult to tease out the difference between, say, a pure CO2 forcing versus a pure solar forcing. Both will have non-winter/daytime components and winter/nighttime components, to different degrees. I've tried to find someone knowledgeable about various climate model runs, to figure out exactly what the difference might be, but so far with no luck, so I can't quantify this in any way. All I can say for certain is that any warming will have both a GHG component and an albedo component as part of the positive feedbacks, and as such the difference between an initial GHG forcing and another forcing may not be as pronounced as one might initially expect, or would want (to be able to discriminate, observationally, between the two forcings). -
chris at 04:17 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Albatross at 03:15 AM on 15 June, 2011 Yes fair enough Albatross. There are two relevant points though: 1) Eric was citing Latif as an indication of "cooling" in the next 20 years. So it's worth pointing out that Latif doesn't predict that at all. He predicts a large warming by the decade centered around 1930. 2) There is uncertainty about the extent to which "natural variability" is suppressing current warming a little. The evidence (including Latif's) suggests that ocean circulation variabilty might be suppressing surface temperatures a tad. We know that the extended solar minimum will also be countering greenhouse warming a little (we expect the drop of solar output from the max to min of the solar cycle to pretty much counter greenhouse-induced warming, although natural variability masks this somewhat). The point is that despite any current short term slowdown in warming, Latif (and pretty much all physics-based projections) indicate that the Earth will be quite a bit warmer by 1930. That's relevant to the subject of this thread. -
Dikran Marsupial at 03:52 AM on 15 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
John Russell You are missing the point. There is no way to give an honest answer to that question that gives no room for misinterpretation by a dishonest adversary, and I rather doubt Prof. Jones was in a position to refuse the interview (given the circumstances). If you think such an answer exists, lets hear it. -
Chris G at 03:38 AM on 15 June 2011The greenhouse effect is real: here's why
CB, FWIW, my presumption on the greater increase over land than water is that it is primarily related to the heat sink/energy transport attributes of land versus ocean. There are thermoclines, but oceans mix more rapidly than dirt; therefore, any energy delta at the surface is distributed over a greater volume over the ocean than over land. Not only does the energy get transported to depth, but also across meridians. I would expect this to have a sort of buffering effect, though thermal inertia might be a better concept to invoke semantically. On clouds, I agree, but, of course, some mechanism would have to drive the change in cloud behavior. Aerosols might do it since more of them would tend to lower the occurrence of supersaturated states. But then there are complications in the tradeoff between water vapor content versus droplet content, and whether they are high clouds or low clouds. For that matter, GCRs _might_ have an influence, but that would require evidence that has so far been lacking, or at least had big gaps, to the best of my knowledge. My two cents. -
Chris Colose at 03:33 AM on 15 June 2011The greenhouse effect is real: here's why
Tom Curtis, My only point was that polar amplification is a rather common occurrence in climate change scenarios, regardless of whether we are talking about deep-time greenhouse climates, Milankovitch (orbital) timescale changes, or modern global warming, and has been simulated for a variety of forcings as well as "aquaplanet only" or other flavors of idealized experiments. Moreover, feedbacks associated with atmospheric dynamics and heat transport (and are not directly dependent on snow or ice) can contribute to polar amplification (e.g., Pierrehumbert 2002, Alexeev 2003; Alexeev et al. 2005; Cai, 2005). The other thing is that there are still recognized problems in simulating the pole-to-equator temperature gradient that proxy indicators report in some early greenhouse climates, so it is not clear to me that we have a convincing and full-proof quantitative theory linking the behavior of the pole-to-equator temperature gradient (and the meridional heat transport carried by the atmosphere and ocean) to the mean climate, so there's still work to be done here. -
Tom Curtis at 03:20 AM on 15 June 2011The greenhouse effect is real: here's why
CBDunkerson @17, the ocean warms slower because it has a greater heat capacity than the land. Consequently it takes more heat for each degree centigrade increase in temperature. Of course, that has no influence on the equilibrium temperature, so once the TOA energy balance reaches equilibrium again, the ocean and land will have warmed equally. Increased cloud cover will indeed warm the nights more than the days, but will only provide an overall warming if clouds are a positive feedback. Of course, increased cloud cover will also tend to warm the stratosphere rather than cool it (although probably not very much). Reduced aerosols will warm the troposphere and cool the stratosphere, but will also increase the diurnal temperature range, and the temperatures of summer relative to winter. If clouds are a negative feedback, reducing clouds will show the same pattern. -
Albatross at 03:15 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Chris @23, To add to you post. Last November RealClimate had a look at how Keenlyside et al's forecast panned out...the short story is that is has not.
[Source]
I really would like to put the whole Mojib Latif debacle that has been doing the rounds for a couple of years now to rest (thanks to the efforts of some misguided journalists and the denialist spin machine, including Lindzen), and it is annoying to see that to this day 'skeptics' are still touting it, even in the face of reality.
Anyhow, I am not sure why we are focussing on this when the post is about future warming and preponderance of extreme heat.
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michael sweet at 02:57 AM on 15 June 2011Websites for Watching the Arctic Sea Ice Melt
DB: that would be nice. Sphaerica's illustration is better than mine.Response:[DB] Done.
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chris at 02:54 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Eric the Red at 23:50 PM on 14 June, 2011"Much of the focus related to "cooling" in the next 20 years comes from presentations like Latif and Easterbrook with regards to the multidecadal oscillation."
Eric, Latif certainly doesn't think the Earth is going to "cool" in the next 20 years. His simulations, taking account of ocean circulation changs that (he thinks) will put a slight break on warming for a decade or so (2005-2015ish), indicates a rather rapid subsequent warming such that by 2030 he consiers we'll be a further 0.4-0.5 oC (globally averaged) warmer. see e.g. Figure 4 of Latif's recent paper on global warming forecast here. -
CBDunkerson at 02:50 AM on 15 June 2011The greenhouse effect is real: here's why
Tom, thanks for the information on the direct component of polar warming from greenhouse gas accumulation. The bit about 'fingerprints' only being unique to greenhouse warming in toto rather than each individually is also new to me. I've been trying to think of another forcing which would cause accelerated night-time warming. Increased cloudiness might work... more clouds during the day = increased albedo and thus cooling / more clouds at night = less heat escaping and thus warming. Also, do you know what the physical mechanism for atmospheric warming being greater over land than the oceans is? Is it just net heat flow? That is, the ocean water absorbing more heat from the air than it expels TO the air? -
chris at 02:42 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
Tom Curtis at 02:15 AM on 15 June, 2011 You may know of this paper which supports the interpretation that under conditions with a solar constant not that different to the present, that the thresholds for Antarctic glaciation is around 750 ppm and for Greenland is of the order of 280 ppm. Since these values correspond to thresholds for the onset of the respective polar icesheets, there is presumably signficant hysteresis for the loss of polar ice under warming conditions (due to offsetting albedo effects). However I think the evidence supports the conclusion that we are already near the CO2 threshold where the Greenland ice sheet is committed to disappear. Haven't looked at data that bears further on this from last couple of years. (I might point out that adelady and I think Eric were referring to the [CO2] threshold which, coupled with appropriate period in the Milankovitch cycles, would be required for descent from the current interglacial to glacial period). -
Albatross at 02:35 AM on 15 June 2011Examining Dr. John Christy's Global Warming Skepticism
Les @68, Thanks for following up and exposing yet more distortion from the 'skeptics'. Why am I not surprised....? -
Chris G at 02:32 AM on 15 June 2011The greenhouse effect is real: here's why
Oh, I just had a thought, probably not an original one, but... I've been puzzling over how we might detect when feedbacks such as permafrost melt (rot) or clathrate releases might overtake the rate of anthropogenic GHG emissions. I was thinking we'd have to wait until after a real effort was made to reduce our emissions and see how much the increase in GHG content reduced. The rate is accelerating; so, I'd first be looking for a reduction in the rate of increase rather than a leveling off. But, if you closely monitored the isotopic signature, you might be able to detect when these feedbacks started to play a significant role a bit sooner. Anyone got any references in this area?Response:[DB] If you go here, you can select your station (this one is centered on Svalbard, for example) and the GHG parameter of interest. HTH
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kampmannpeine at 02:28 AM on 15 June 2011SkS Weekly Digest #3
@John Cook, I would prefer to receive the "Badget" alone ... so: is that feasable?? -
Chris G at 02:19 AM on 15 June 2011The greenhouse effect is real: here's why
Arkadiusz, I'm not sure what your point is. Yes, carbon released through geologic processes will have a similar isotopic signature as long-sequestered carbon released through the burning of fossil fuels. Rocks weather more when they are exposed to weather than when they are buried under ice. Weathering of rocks draws down the level of CO2, and this tends to have a slow (very slow) balancing effect on carbon released from whatever sources. I think you are implying something, but what that is, is not clear. -
chris at 02:17 AM on 15 June 2011The greenhouse effect is real: here's why
On the asymmetry of polar amplification under enhanced greenhouse scenarios. The delayed Antarctic response to enhanced greenhouse warming was predicted from models of various complexity from up to 30 years ago as described in a 2007 review by Manabe and Stouffer. Can't find an online version of the paper, but I summarized some of the points from that review in a post here some time ago. -
Tom Curtis at 02:15 AM on 15 June 2011Forecast: Permanently Hotter Summers in 20-60 years
adelady @19, studies of CO2 levels over the last 500 million years show a CO2 threshold of 1000 ppm, above which ice ages do not occur. Because the sun has been warming in the long term, that threshold has probably declined (and is inexact), but is certainly not below 300 ppm. There is some argument that it is now around 400-500 ppm, but that is not a consensus opinion. Following your link, 300 G tonne release represents anthropogenic emissions to date. 1000 G tonnes release represents the budget for a 450 ppm stabilisation (from memory). -
michael sweet at 02:07 AM on 15 June 2011Websites for Watching the Arctic Sea Ice Melt
Sphaerica, Your illustration with the boxes is really nice. Hopefully people will see it in the comments if they have trouble seeing the difference in the main post. I think it is too late to change the post now.Response:[DB] It can be done via an Addendum at the end. If you wish, I can do it for you.
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Mike2811 at 02:04 AM on 15 June 2011Phil Jones - Warming Since 1995 is now Statistically Significant
I'd just like to support (belatedly) Dikran's point about the incorrect interpretation of classical p-values as levels of belief. Yes the correct interpretations are hard to understand, but putting incorrect interpretations like "we could say with 93% confidence that..." does no-one any favours. -
Bob Lacatena at 01:58 AM on 15 June 2011Examining Dr. John Christy's Global Warming Skepticism
74, Tom, I actually don't doubt that he has the education and experience. What I doubt is that he's taking the time to properly use his own personal education and skills to learn climate science. I think he can, but the rather low level of his posts to date demonstrate that he has not done so. He just needs help getting his focus on actually learning, rather than trying to jump immediately to finding the flaws in climate science without taking the time to actually build the foundation that would be needed to do so (or, in actuality, to understand how few flaws there are, what they are, what the implications are, and what is pretty solidly understood in the field). -
Chris G at 01:54 AM on 15 June 2011The greenhouse effect is real: here's why
Paul D, I think you misunderstand CBD. I don't think he was attempting to discredit the main theme; I think he was merely asking honest questions on points that were not clear. Tom and Chris C, Thanks, I was thinking along those lines, but your answers are more clear, or at least the combination of them is, than I probably would have produced. I think if you increase the insulation qualities of the atmosphere, you end up with a more even distribution of energy, but, yeah, albedo changes through snow and ice loss also play a part, and those changes can have multiple causes. Related to the article itself, I'm thinking the greenhouse effect is more directly an effect related to energy, and temperature is really just a proxy for energy content. Different substances have different heat capacities, and winds, evaporation/precipitation, convection, phase changes (ice vs. water), are all affected by changes in energy content that may be less easy to measure than changes in temperature. Temperature is a pretty good proxy, but it isn't the only change taking place as a result of the increase in GHGs. -
Bob Lacatena at 01:53 AM on 15 June 2011Examining Dr. John Christy's Global Warming Skepticism
66, jonicol,Surely the most important aspect of this discussion is to discover the underlying behaviour of a green house gas and the influence of natural climate variation which has to be understood before one can quantify the effect of CO2.
Yes. Absolutely. And this has been done. That you do not understand it does not warrant the implication that it is not understood. As has been stated previously, there is a wealth of information readily available for anyone who takes the time to look, especially if you already have the proper foundation in the hard sciences. Your cooperation is requested in doing your best to educate yourself, either by reading the many sources of serious information available, or by asking meaningful questions here (on the appropriate threads), through which people who do understand the science can help you (and others) to learn, but please, do so without adding backhanded implications that the science is wrong. If you have serious reason to believe this is the case then you shouldn't be asking questions, and should instead be offering a substantive argument to make your case. Claiming ignorance, while simultaneously professing doubt and dropping half-arguments, is unhelpful. But asking questions -- for the sake of learning -- is good. Please go ahead and do so. -
Tom Curtis at 01:50 AM on 15 June 2011The greenhouse effect is real: here's why
Chris Colose @8, would you care to expand on your disagreement. I'm always looking for a chance to learn more. -
michael sweet at 01:49 AM on 15 June 2011The greenhouse effect is real: here's why
Remember that Arrhenius in 1896 predicted the fingerprints of AGW (he did not predict stratospheric cooling, the stratosphere had not been discovered yet). The fingerprints have been known for over 110 years and have been extensively tested and confirmed. This also counters the "skeptic" argument that AGW cannot be experimentally falsified. No other method of warming includes all the fingerprints. -
Tom Curtis at 01:46 AM on 15 June 2011Examining Dr. John Christy's Global Warming Skepticism
Sphaerica @72, John Nicol claims to be a former Dean of Science at James Cook University. I have an independent reason to believe he was connected to that University. -
Eric the Red at 01:40 AM on 15 June 2011The greenhouse effect is real: here's why
Chris, I agree. As Tom mentioned, the polar amplification is largely one-sided; large warming in the Arctic, virtually no change in the Antarctic. I do not necessarily agree that the difference is due the loss of sea ice as the Arctic warming occurs before the sea ice begins to retreat. It could amplify the warming, but the initial warming should occur at both poles. I maintain that warming of the North Atlantic had much more effect on the sea ice and temperatures.
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