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Alec Cowan at 22:08 PM on 20 April 2011Christy Crock #4: Do the observations match the models?
Again: Can anyone comment on Johnston (substantiating it by citing Bender et al 2006, one of only 3)GCMs may be biased towards more warming by overestimating the Earth's albedo[from: http://www.johnstonsarchive.net/environment/gw.html ---not linked intentionally] Don't forget he is a PhD in Physics claiming to be "a research physicist in the field of space physics" Feel free to compare that phrase with Bender 2010 "Planetary albedo in strongly forced climate, as simulated by the CMIP3 models", who says in the abstract:In an ensemble of general circulation models, the global mean albedo significantly decreases in response to strong CO2 forcing. In some of the models, the magnitude of this positive feedback is as large as the CO2 forcing itself.C'mon! Don't be shy! Don't you feel there's a lot of quacks out there? I also want to thank Berényi Péter for promoting one change in me and a tiny little bit of epiphany. First, owing to the analysis that his/her words incited me to do, I have now a much higher respect for models and modeling. If one of those 20 models can use the following grid:and yet obtain values that resemble the real ones, I only can say "Chapeau!". The image is taken of some internal paper dealing with the the details of their model, publicly available in their website. I'm telling which one by saying it was made in the terre des nos aïeux. The little bit of epiphany is that Bender et al 2006, precisely by means of the implications of the image dropped here by Berényi Péter and by settling the question above in this message, it all provided me with a very real case of what James Wight says in this post, that is, "And where they do diverge from climate models, the observations are usually even more alarming." -
funglestrumpet at 21:06 PM on 20 April 2011Muller Misinformation #4: Time to Act
Bern @ 42 No, the cause of global warming does not matter in the short-term. Simple question: Do greenhouse gases have a warming effect on the atmosphere? Answer: Yes. If by the most remote of chances the current warming were due to some hitherto unknown cause rather than us humans, would reducing greenhouse gas production help reduce the amount of warming taking place? If the answer is yes, and I rather think that it is, then we should reduce greenhouse gas production, period. Put it another way, if your cellar is filling with water, would you switch on the pumps immediately, or would you wait until after you were sure of the cause? Much more important is the fact that the politicians will in the main react to public opinion. The public sees both sides arguing about the cause of the warming and thus forms the opinion that the cause is far more important than it really is. In the long-term it is very important, because it is going to cost a lot and any nation seen to have contributed more than most will be expected to pay more than most. I will bet a pound to a pinch of snuff that that is what really motivates most of those politicians currently arguing about the cause of climate change. Unfortunately, all this 'It is us. No it isn't us.' palaver is stopping a sizeable chunk of the public from demanding action because they think we have to resolve the issue of the cause before we can act. Meanwhile, the politicians wring their hands and demand a clearer mandate. We should call a truce in the argument about the cause and agree on the need for action. If the sceptics can prove that it is all going to subside, then we can all breath a sigh of relief. I very much doubt that such proof exists, and if it doesn't, then the need for action becomes overwhelmingly obvious. That is the debate the public should be having a grandstand view of, not the tired old 'We are to blame. No we aren't.' one. Small wonder the pubic is switching off. The argument keeps going round in circles. There will be ample time to aportion blame later, when we have a clearer view of the size of the problem and even more proof of the cause (if that is possible). -
Berényi Péter at 20:39 PM on 20 April 2011Christy Crock #4: Do the observations match the models?
#38 Albatross at 07:46 AM on 20 April, 2011 In the meantime, Re the claim, "Basically the same set the IPPCC AR4", IIRC that is not true. Albatross, you are getting desperate. In the good old days your claims used to have some root in reality, not anymore, it seems (don't tell me you're confused by typos). Randall, D.A., R.A. Wood, S. Bony, R. Colman, T. Fichefet, J. Fyfe, V. Kattsov, A. Pitman, J. Shukla, J. Srinivasan, R.J. Stouffer, A. Sumi and K.E. Taylor, 2007 Cilmate Models and Their Evaluation. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Look up Table 8.1 in page 597. The full set of climate models used in the report is given there, twenty three of them. These include all the twenty models Bender 2006 used and three more: BCC-CM1, CGCM3.1(T63) & GISS-AOM. It is basically the same set indeed. Before you mention it I do know the title of the document should have been "Climate Models and Their Evaluation" and not "Cilmate Models and Their Evaluation" (as there's no such a word as "cilmate" except in the EU), but they say on the first page of the document that it has to be done like this (under "This chapter should be cited as:") and who am I to ignore their request? Also, don't even think about using the webalized version of the document, they simply left out the last four rows of Table 8.1 there. Shows how carefully crafted it is. -
Dan Olner at 20:34 PM on 20 April 2011A Convention for Persons Displaced by Climate Change
Oops, apologies - wasn't UNEP getting it wrong, it was the UN news centre. -
Alec Cowan at 20:33 PM on 20 April 2011Clouds provide negative feedback
RW1 wrote: "I think the confusion here lies somewhere in between the definition of 'forcing' and that there are many other things in the climate system, other than anthropogenic CO2 (and GHGs), that are changing and subsequently inducing new 'forcings' independent of temperature. As just one example, take the fluctuations of Arctic and Antarctic sea ice extents, which we know are largely driven by factors other than temperature (wind patterns, ocean currents, etc,)."What boils to: - I know it is a system - I know CO2 is a factor - But the cause must be elsewhere, darn. - Let me uncouple the system and I'll tell why. Let also that the uncoupling makes Temperature an irrelevant variable to the climate system. "Why would you stop when you can rev up?" (signed: Thelma & Louise) -
Dan Olner at 20:32 PM on 20 April 2011A Convention for Persons Displaced by Climate Change
GregS: the only line I managed to find that UNEP got wrong (and this was, interestingly, a link via the first ever constructive discussion I've had on WUWT!) at this press release from 2008: "In a related development, the UN Environment Programme (UNEP) said in a statement today that a new kind of casualty was being created by climate change: the environmental refugee." ... where the writer misinterprets this article. Clearly, the 'environmental refugee' concept is not new, and isn't solely climate-change related. And incidentally, the original map doesn't have any dates on: it just shows potential vulnerabilities. It's irrelevant. It's hard to know how to react: like so many other memes like this, it's hurtled round the interwebs. The story should be the initial confusion of 'climate' and 'environment', and that some guy thinking tropical island census data falsifies anything can somehow lead to so many other venues uncritically buying into it. -
explorer40503 at 20:10 PM on 20 April 2011A Convention for Persons Displaced by Climate Change
Dan @3...I had the same "discussion" over at Judith Curry's Place. Judith herself said, 'The unfounded and senseless predictions of the UNEP could very well “backfire and result in policies that marginalise the poorest and vulnerable groups. ”' The willingness of people of even her stature to accept something as fact without actually looking into the sources is scary. The sources the folks there were pointing me to prove UNEP's duplicity and ignorance, included a UNEP press releases, Natural Disasters Contribute to Rise in Population Displacement. The closest it came to climate change refugees was a blurb in there saying the Red Cross had said "climate change disasters are currently a bigger cause of population displacement than war and persecution." Yet they just kept repeating their idea that UNEP had made this wild prediction that is not true based on the map in the Aisian Correspondent piece you mention. I walked away from that discussion thinking a lot of people are just looking for witches to burn. GregS -
Alec Cowan at 20:05 PM on 20 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
@Ken #138 I love when they play bonneteau -follow the bee, follow the lady, three-card trick, whatever it is called in your turf-. So let me summarize your post: 1)You cannnot present any evidence that Knox & Douglass' (double s) figures are any deeper than 0-700m because, in your own words,"Why would K&D need to quote only their 'own' figures for ocean depths other than 0-700m?", followed by a change of subject. Let's see it again in the way you wrote it:"You simply cannot find K&D saying their own figures are for any deeper than 0-700m." Why would K&D need to quote only their 'own' figures for ocean depths other than 0-700m?Your change of subject includes assorted content that is a hint that indeed you browsed the paper once more and tried to find what I asked but you couldn't. Regarding the part of your message I quoted, we say "y mi tía tenía una bicicleta" ("and my aunt used to have a bicycle"), the popular render of a non sequitur combined with the obvious { - snip -} evasion in the answer. 2)You played "where's the queen?" or "where's the little ball" with a couple of papers and by adding many many words like a snowstorm -or a snow job- you pretend there's something there that has indicial value What you said boils to 0-700m layer from Knox & Douglass for 2003-2008 (when the bottom is warming) and your appreciation of it cooling, plus some data from +4000m for 1990-2000 (when the surface is warming) from another paper, plus another chunk of data for 1000-4000m around the Pole with -no period declared, why you'd bother to-, and with this half cooked Frankenstein's monster you pretend to get some kind of a trend that, wait!, it confirm what you have been saying so far. Here your { - snip - } technique of chatting and chatting and chatting couldn't hide that the time span doesn't match, the sources are cherry picked and 700-1000m layer is set aside and 1000-4000m is set aside for 90-95% of the oceans. { - snip - } You may call yourself to silence now or you may use the technique of the manipulator and select isolated phrases of my message to try to make some fuzz of it and attempt to dilute the consequences of your blunder.Moderator Response: [mc] Less invective, more science. -
Bart Verheggen at 19:30 PM on 20 April 2011Muller Misinformation #4: Time to Act
The two requirements for Muller's supposition to be true are at odds with each other (at least according to other skeptics such as Lindzen): With currently known forcings, a low climate climate sensitivity (req. 1) would imply a small aerosol forcing (the opposite of req. 2) in order to be compatible with the observed warming (as was discussed on this site by Dana and myself recently). -
Dan Olner at 18:31 PM on 20 April 2011A Convention for Persons Displaced by Climate Change
Charlie A: I responded to that meme just the other day: it's not true. The subject was *environmental* refugees. That's a much larger category: I quote extensively from the original research in that link. Factors affecting environmental refugees from the original 1995 report: food and agriculture; water shortages; deforestation; desertification; population pressure; urbanization and mega-cities; unemployment; poverty; extreme weather events. Global warming is mentioned as a multiplier that will make the issue worse, but the subject was never "climate refugees." What's more bizarre to me: this all seems to have started from that Asian Correspondent piece, where they attempt to show the predictions were wrong by citing census data from four tropical islands. Does that strike you as a good way to assess the environmental refugee problem? (Or indeed the "climate refugee" problem they thought they were attacking?) I haven't dug much deeper, but there does appear to be some confusion among people writing the UNEP press releases as well, which hasn't helped. However, you need to go back to Prof Norman Myers' original research. In 1995, there were already, by some estimates, 25 million environmental refugees. He was estimating (not even really forecasting) another 25 million in the following 15 years - though if you read the research, these numbers are surrounded with caveats. For some reason, critics seem to ignore all the caveats. As far as I know - and I'd love to hear from others here - there has been no systematic attempt to define and measure the problem since then. Perhaps for good reason: as a migration issue, it's very complex - again, something Myers argued in his original piece. Here's Myers: "These estimates constitute no more and no less than a first cut assessment. They are advanced with the sole purpose of enabling those to ‘get a handle’, however preliminary and exploratory, on an emergent problem of exceptional significance." He's right of course: it is a massively important issue. That people should dismiss it so lightly, based on someone checking four island's census numbers, hardly suggests to me they have any interest in actually trying to understand the problem. Anyone unable to see the difference between "climate" and "environment" refugees, and the relations betwen the two, is going to have problems contributing to this discussion seriously. -
Tom Curtis at 17:39 PM on 20 April 20112nd law of thermodynamics contradicts greenhouse theory
LJRyan @1005: you are now circling back over ground we have already covered. Specifically, you are assuming that Atmdn is not absorbed by the surface. If it were absorbed by the surface, then at equilibrium (when Atmup= S = 240 Watts/m^2), Surf = S plus Atmdn = 240 + 240 Watts/m^2 = 480 Watts/m^2. It follows that you have conservation of energy at equilibrium and, as shown a net gain in entropy. Only by ignoring Atmdn, or assuming that it is not absorbed by the surface can you escape this conclusion. However, rather than fruitlessly attack this point directly, and just rehashing old ground, I ask that you answer the following questions (and some follow ons) and we'll see if we cannot get a better understanding obliquely: Imagine you have to plates, both having an emissivity of 0 on the backside, and on the edges, but having an emissivity of 1 on the front side. The first plate (plate A) has a surface area with emissivity 1 of 1 square meter, while the second plate has a surface area with emissivity 1 of 2 square meters. Both plates are perfectly conductive, except for a high resistance wire (heating element) embedded in the plate. A 480 Watt current is fed through the heating element. Assuming no losses due to resistance outside of the heating element: 1) What will be the temperature of the two plates? 2) Is there any contradiction of the laws of thermodynamics in this arrangement? -
adelady at 17:37 PM on 20 April 2011CO2 limits will harm the economy
Tom, I don't know how it might work in other countries, but Australia's proposal for carbon tax on petrol should have no, nil, zilch effect on retail prices. All they're proposing is that any carbon tax will be offset by matching reductions in excise. No change in the amount going to the government, but it will be paid from the oil companies' pockets instead of the user's. -
alan_marshall at 17:30 PM on 20 April 2011A visual depiction of how much ice Greenland is losing
Visualising the Greenland Ice Loss This is a rather late comment prompted by John Cook’s post on 16 April 2011. Because we live on a more or less flat surface, I have been thinking about the 286 billion tonnes lost in 2009 in terms of urban areas. With one tonne of fresh melt water at 4 degrees C having a volume of one cubic metre, the loss would sufficient to inundate an area 100 km x 100 km to a depth of 28.6 metres. It would flood the city of Brisbane (1636 sq. km) to a depth of 175 metres. It would flood the city of London (1610 sq. km) to a depth of 177 metres. It would flood the city of Los Angeles (1290 sq. km) to a depth of 222 metres. It would flood the city of New York (790 sq. km) to a depth of 362 metres. Finally, it would flood the city of Washington DC (177 sq. km) to a depth of 1,616 metres. That would fix those Republican skeptics! -
adelady at 17:27 PM on 20 April 2011A Convention for Persons Displaced by Climate Change
I'm not so sure they're all that wrong. Pakistan has 4 million people still homeless - officially - since the floods displaced 20 million. Personally I'd double that figure. Darfur has a few causes, climate among them, a few million there. How many Mexicans are crossing into the USA, North Africans crossing the Mediterranean to Europe? Within Africa there are many groups on the move even if they've not crossed any borders or created any visible fuss (visible to us that is). As well as all the quiet, tiny tragedies affecting a few thousand here and there that we never hear about. It may not be 50 million, but I doubt it's an insignificant number. -
Tom Curtis at 17:11 PM on 20 April 2011CO2 limits will harm the economy
Giles @18: From his first link: "Oil prices, which surged above $126 a barrel on Friday -- their highest level in 32 months -- retreated on Monday as the African Union signaled progress in Libyan peace talks." Reality check: Each barrel of oil used as fuel releases 0.45 tonnes of CO2 into the atmosphere (highest of three estimates found on the web). Introductory carbon prices are expected to be around thirty dollars per barrel, so that represents a price increase of 13.5 dollars, or just over 10%. Given the volatility of oil prices, that is not an earth shattering rise and would certainly not be, by itself, enough to drive a nation into recession. Indeed, with crude oil representing just 0.04%, the direct inflationary impact of such a carbon price driven price rise would only by a 0.004% blip in inflation. The second link discusses the EU bailout of Greece, and so far as I can tell contains no relevant discussion to this topic. The third link is a discussion of Standard & Poor's downgrading of the outlook on the US financial position. Ironically, that downgrade is likely to have a greater direct adverse impact on the US economy than a carbon tax would, but as it is, it is irrelevant to the topic of this thread. So Gilles's apparent argument to date is that: 1) The real world contains inflationary risks that can potentially lead to recessions; and 2) A carbon tax's contribution of an estimated 0.004% to inflation is so large that it significantly raises those risks. Oddly, I am not convinced by his logic. -
Charlie A at 15:57 PM on 20 April 2011A Convention for Persons Displaced by Climate Change
Per a 6 year old prediction by UNEP, there should be 50 million climate refugees today. Spiegel International article: UN Embarrassed by Forecast on Climate Refugees -
adelady at 15:15 PM on 20 April 2011CO2 limits will harm the economy
"... a GDP reduction of less than 1%..." Can I presume that GDP is conventionally calculated? In that case electricity, petrol, diesel, coal not sold because of reduced sales (through reduced demand by negawatts or distributed generation investments) will indicate a reduction or "loss" of production - which is exactly what we want in the first place. This would be a bit like saying the country's families are starving - because they started buying packets of seed to grow their own instead of buying fruit and vegetables grown by others. -
scaddenp at 15:11 PM on 20 April 2011Clouds provide negative feedback
"As just one example, take the fluctuations of Arctic and Antarctic sea ice extents, which we know are largely driven by factors other than temperature (wind patterns, ocean currents, etc,). " Splorff! Long term (30 year) change in arctic albedo is driven ultimately by change in temperature. Short term variation from year to year depends on wind/ocean etc. Oh and what is changing ocean/wind? I think it is time to come up with some evidence for unforced climate change if you are arguing about the definition of forcing. -
scaddenp at 15:08 PM on 20 April 2011Clouds provide negative feedback
RW1 - the answer then to "Yes, but I don't see how CO2's effect is fundamentally different than water vapor, especially if water vapor is the primary amplifier of warming (CO2 induced or otherwise)." CO2 is non-condensated gas. That is why the same forces that modulate or control water vapor's radiative forcing, do not modulate and control CO2's radiative forcing. -
RW1 at 15:02 PM on 20 April 2011Clouds provide negative feedback
KR (RE: 66), "Cause => Effect CO2 is a cause, changing (primarly and from anthropogenic actions) independent of temperature, while water vapor and clouds respond promptly to temperature and don't change on their own, and are hence amplifying effects of temperature change." I think the confusion here lies somewhere in between the definition of 'forcing' and that there are many other things in the climate system, other than anthropogenic CO2 (and GHGs), that are changing and subsequently inducing new 'forcings' independent of temperature. As just one example, take the fluctuations of Arctic and Antarctic sea ice extents, which we know are largely driven by factors other than temperature (wind patterns, ocean currents, etc,). Yes, anthropogenic CO2 'forcing' is a cause and not an effect of temperature, but even without anthropogenic CO2, the climate is frequently perturbed by new 'forcings' - not all of which are due to temperature changes, yet the globally averaged temperature remains very, very stable. -
Bob Lacatena at 14:26 PM on 20 April 2011Clouds provide negative feedback
RW1,In short, the cloud feedback is huge.
You love to exaggerate things. The cloud feedback is important, not huge. It's more important if it is neutral or negative, but you've shown no evidence other than that you think common sense says so, while hundreds of climate scientists think otherwise. But even if you proved clouds to be a weak negative feedback, it would reduce sensitivity to anywhere from 1.9 to 3.4 (versus 3 to 4.5), given that 3 is the current best estimate, but also at the low end of the range. Even 1.9 is very, very bad, especially since we're currently taking no action to avoid it. But first you need to submit some evidence beyond your "plain, everyman logic" to prove that clouds are even a neutral feedback, let alone negative. And that evidence has to contradict all of this evidence to the contrary. I'm afraid a sensitivity below 3˚C is very, very unlikely.But what causes the temperature to drop and the water vapor to be removed from the atmosphere if water vapor is the primary amplifier of warming?
This question is evidence that you don't understand how things work. You need to go study more. If this were the case, the planet would never, ever cool, no matter what....but I don't see how CO2's effect is fundamentally different than water vapor..
Because water vapor will increase or decrease in the atmosphere fairly quickly in response to temperature. Raise the temperature, raise the water vapor. Lower the temperature, lower the water vapor. CO2, on the other hand, will stay in the atmosphere for hundreds of years, even if, for example, a large volcanic eruption temporarily lowers temperatures....why would the response to water vapor warming in the system be any different than warming caused by CO2?
There's no difference in the warming. What is different is that the CO2 won't drop out of the atmosphere when the temperature drops (for instance, during the winter).Why would the same forces that modulate or control water vapor's radiative forcing, not modulate and control CO2's radiative forcing?
There are no such forces for either. This isn't a human designed system with controls and balances. It's nature, and it's (fortunately) got a simple balance to it, and one that should be very hard to shove, but we've found a way to do it. The point is not how each one (water vapor vs. CO2) affects temperature. The point is that water vapor content is itself affected by temperature on short time scales, while CO2 is only affected on very, very long time scales. And, in fact, there is a positive CO2 feedback (such as outgassing from the ocean) that will, in the long term, increase CO2 levels even further. -
dana1981 at 14:24 PM on 20 April 2011CO2 limits will harm the economy
I think Gilles should try reading the post he's commenting on here, as it refutes every claim he made. Just as one example, try reading the Impact on Gasoline Prices section. -
RW1 at 14:16 PM on 20 April 2011Clouds provide negative feedback
scaddenp (RE: 69), "The atmosphere has a temperature gradient. At a certain height, water condenses out. CO2 does not." I know. "Note that in our current AGW-world, CO2 is not a feedback." Agreed. -
scaddenp at 14:08 PM on 20 April 2011Clouds provide negative feedback
The atmosphere has a temperature gradient. At a certain height, water condenses out. CO2 does not. Maximum water content in atmosphere is temperature-dependent. Maximum CO2 is not. Note that in our current AGW-world, CO2 is not a feedback. The mechanisms are too slow to have produced much GHG feedback yet. -
RW1 at 14:00 PM on 20 April 2011Clouds provide negative feedback
Sphaerica (RE: 58), "Yes, because water vapor responds quickly to changes in temperature. There's nothing anyone or anything can do to inject water vapor into the atmosphere and keep it there. The temperature will drop, and the water vapor will condense and things will return to normal." But what causes the temperature to drop and the water vapor to be removed from the atmosphere if water vapor is the primary amplifier of warming? "This is not the case with CO2, whether it is added anthropogenically or geologically. No matter how it gets there, once it does get there, it stays there for a very long time and it's effect forces the climate to follow suit." Yes, but I don't see how CO2's effect is fundamentally different than water vapor, especially if water vapor is the primary amplifier of warming (CO2 induced or otherwise). In other words, why would the response to water vapor warming in the system be any different than warming caused by CO2? Why would the same forces that modulate or control water vapor's radiative forcing, not modulate and control CO2's radiative forcing? The surface has no way of distinguishing where the radiative 'forcing' originated from - water vapor or CO2. All the surface 'knows' is its total energy flux, as it determines the surface temperature. -
scaddenp at 13:55 PM on 20 April 2011Clouds provide negative feedback
RW1 - clouds are not forcing because unless you have something like GCR changing clouds, there is no way to produce a long term change in cloud cover without something else being responsible for changing the temperature. If your vision of reality is right, then you would have world with no change to GHG, solar, or aerosols, going through climate change (ie a long term change in radiative balance). Now plenty of that kind of internal variability in short time scales - weather. But no evidence whatsoever of any such change on long term. -
Gilles at 13:49 PM on 20 April 2011CO2 limits will harm the economy
Now for the *real* impacts of carbon pricing : http://www.foxbusiness.com/markets/2011/04/11/oil-prices-inflation-pose-risk-global-economy-imf/ http://www.nytimes.com/2011/04/19/business/global/19euro.html http://blogs.reuters.com/james-pethokoukis/2011/04/18/the-politics-of-sps-u-s-debt-warning/ = recession, unbearable debts, economic crisis. That's the real world.Moderator Response: [DB] Please demonstrate the relevance of a link by providing some context showing why its relevant to the thread at hand. Otherwise, you're merely vomiting forth newspaper links (in this case) with no demonstration that you've actually read the post you're commenting on. Future posts lacking such context will receive moderation. FYI: as in the real world of astrophysics, peer-reviewed science publications carry the most weight, don't they? -
Clouds provide negative feedback
RW1 - At the risk of repeating myself: Cause => Effect CO2 is a cause, changing (primarly and from anthropogenic actions) independent of temperature, while water vapor and clouds respond promptly to temperature and don't change on their own, and are hence amplifying effects of temperature change. Water vapor and clouds change in response to temperature. If you have any evidence supporting water vapor or cloud changes independent of temperature, I suggest you publish it. Nobody else has found any such evidence - I will (I believe correctly) take assertions to that effect as just wishful thinking without such evidence. -
RW1 at 13:30 PM on 20 April 2011Clouds provide negative feedback
muoncounter (RE: 62), "I thought there was agreement that water vapor doesn't stay in the atmosphere that long." It doesn't, but it also doesn't take 40 years for changes in water vapor concentration to effect changes in temperature. For example, a sunny humid day is generally warmer than a sunny dry day, all other things being equal. "Ah, we've come full circle, as you've said that before: It's also inline with the sensitivity only being about 0.6 C" That was assuming only half of the 3.7 W/m^2 from 2xCO2 is incident on the surface. For the purposes of this discussion and elsewhere here, I've accepted that the full 3.7 W/m^2 affects the surface (at least for now). -
RW1 at 13:19 PM on 20 April 2011Clouds provide negative feedback
KR (RE: 59), "Not just claiming that, but stating that with plenty of evidence. CO2 has been changing due to anthropogenic emissions, while water vapor and clouds have been changing strictly due to temperature changes." Not necessarily strictly temperature changes, but even so, I don't see how that excludes them from being a 'forcing'. Do water vapor changes not also cause temperature changes? Do cloud changes not also cause temperature changes? Surely they do. -
muoncounter at 13:19 PM on 20 April 2011Clouds provide negative feedback
RW1#62: "why doesn't it take 40 years for the forcing of water vapor in the atmosphere" I thought there was agreement that water vapor doesn't stay in the atmosphere that long. I don't know how things are where you live, but I wipe a lot of that water vapor off my car windows every morning. #61: "the average sensitivity could easily come down to 1 C or less." Ah, we've come full circle, as you've said that before: It's also inline with the sensitivity only being about 0.6 C . Of course, the temperature record doesn't support that contention, as we've already seen 0.8C with far less than a doubling of CO2. -
Tom Curtis at 13:15 PM on 20 April 2011Muller Misinformation #4: Time to Act
Moderators, I have just noticed that I accidentally included the wrong link in my post above. The first link should be to The economic impacts of carbon thread: http://www.skepticalscience.com/argument.php?a=36#48902 I would greatly appreciate your fixing the hyperlink.Moderator Response: [mc] Done! Beat the Yooper to it for once. -
RW1 at 13:11 PM on 20 April 2011Clouds provide negative feedback
muoncounter (RE: 60), "The time it takes to double CO2 through anthropogenic input has nothing to do with the time it takes for the forcing of CO2 already in the atmosphere to increase temperature, which is, of course, already in progress. I don't understand how you mixed up the two. See the 40 year lag thread I linked earlier for discussion of this." Sorry for the misunderstanding, but my question then is why doesn't it take 40 years for the forcing of water vapor in the atmosphere to increase (and decrease) temperature? -
More Carbon Dioxide is not necessarily good for plants.
Stephen Baines - I wholeheartedly agree. Johnd appears focused on technological seed/breed development to escape these consequences ("However with the will, technology will help over come some this also."), although he has put forward no actual data to support this - the FACE results appear to be exploring what is within the range of existing plant variants, rather than demonstrating that selective breeding can produce superplants. There does appear to be a small yield effect with increased CO2 for some species (wheat, yes, soybeans, no), fighting with decreased nutritional value, much larger hydrological changes and heat stress, with an end result of at best little change in productivity, but a more likely decrease thereof. -
Tom Curtis at 13:03 PM on 20 April 2011CO2 effect is saturated
novandilcosid @87, the claim I was responding to is quite specific:"There are some other interesting aspects: The atmospheric window is almost constant, the conduction is almost constant, so the heat transport from the surface into the atmosphere is almost a constant whatever the surface temperature. What happens as the temperature rises is that the Net radiation (surface radiation less radiation through the window less back radiation) DECREASES and this balances the increase in water vapour condensation."
So according to you for any two temperatures T1 and T2, e1sT14-W-Rback1+E1+C1=e2sT24-W-Rback2+E2+C2, where T stands for temperature, W for energy escaping through the atmospheric window, R for back radiation, E for evaporative energy transport (latent heat), C for conduction, e for the emissivity, and s for the Stefan-Boltzman constant. I can allow (as indicated in the notation) that energy escaping the atmospheric window is near constant for small changes in temperature with no changes in GHG concentrations. However, all other factors are variable with temperature. Specifically, you insist that an increase in temperature will result in an increase evaporation. But increased evaporation reduces soil moisture content, thus reducing the emissivity of the soil (factor 1). It also increases the emissivity of the lowest portion of the atmosphere, thus reducing the altitude of emission (factor 2), and at the same time reduces the lapse rate which increases the temperature at any given altitude (factor 3). Factor's (2) and (3) combine to increase back radiation. (The increased humidity will also decreases the size of the atmospheric window, but we will neglect that.) Increasing temperatures also increases wind speed globally, thus increasing conductive heat transfer by increasing the rate of turn over of the layer of atmosphere in immediate contact with the surface (factor 4). Increased humidity will also increase conductive transfer because of the high heat capacity of water vapour. So, you have at least four hetergenious factors you need to juggle to gain your equality, and only one term (W) which can be eliminated from the equation. The proof that change in net surface radiation equals the negative change in net evaporative transfer, therefore does not follow, and is highly implausible. -
RW1 at 13:02 PM on 20 April 2011Clouds provide negative feedback
Sphaerica (RE: 57), "What is your point about clouds again? Now that you've proven that they are a strong positive feedback, why are we discussing them?" Because if a lot of the enhanced warming comes from positive cloud feedback, and the cloud feedback is NOT really positive - but negative (even slightly negative), it is going to reduce the projected amount of warming significantly. The IPCC even says that if the cloud feedback is neutral, it would reduce the average sensitivity to 1.9 C instead of 3 C. That's a reduction of over half of the enhanced warming. If the cloud feedback was even moderately negative, the average sensitivity could easily come down to 1 C or less. In short, the cloud feedback is huge. -
Stephen Baines at 13:02 PM on 20 April 2011More Carbon Dioxide is not necessarily good for plants.
I'm with Marcus. Johnd, your characterization of the arc of this debate bears no resemblance to what I have observed, although I suspect we fly in different circles. Biogeochemical models have built in CO2 fertilization in response to increasing CO2 since the 80's, with different responses for C-3 and C-4 plants. The FACE experiments were designed to parameterize those models under a range of conditions, and to test for acclimation and ecosystem level knock-on effects. What really came out of the FACE experiments though was how variable plants were in this respect, and how tricky it is to generalize about responses more specific than photosynthesis. In the end, the effects of CO2 (0-50%, depending on plant) are small and variable compared to responses to precipitation. Why? Well, there is a ceiling to the CO2 effect, it is fully realized for only some species under very specific circumstances (high nutrients, high water, high light). The effect is even less notable for net ecosystem productivity. Water limitation, by contrast is a hard limit for plants, and is very hard to overcome technologically without consequences (ask the people in the Owens "River" Valley!). Variation in precip results in 2 orders of magnitude variation in primary production between ecosystems. That trumps CO2 as a limiting factor every time. Expansion of arid zones will not be compensated on a global level by CO2 fertilization. Seeing how we've dealt so far with famine induced by precipitation in Africa, I'm also not as optimistic about application of technology or of the political will to address the problem in places where rich people don't tread. -
muoncounter at 13:01 PM on 20 April 2011Clouds provide negative feedback
RW1#54: "I don't understand the question." Well, you stated "Anthropogenic CO2 forcing is very gradual," I asked how you to substantiate this; you responded that "it's claimed to take about 100 years to double CO2." The time it takes to double CO2 through anthropogenic input has nothing to do with the time it takes for the forcing of CO2 already in the atmosphere to increase temperature, which is, of course, already in progress. I don't understand how you mixed up the two. See the 40 year lag thread I linked earlier for discussion of this. -
Clouds provide negative feedback
RW1 - "If water vapor is not a 'forcing' in the climate system, then how can CO2 be a 'forcing'? Are you claiming that increased water vapor in the atmosphere is not a 'forcing', but increased CO2 is a 'forcing'?" Not just claiming that, but stating that with plenty of evidence. CO2 has been changing due to anthropogenic emissions, while water vapor and clouds have been changing strictly due to temperature changes. This is part of the grand scheme of Cause -> Effect, RSVP; CO2 (due to our actions) is a recent cause of climate change, water vapor and clouds respond as an effect. -
David Horton at 12:43 PM on 20 April 2011Muller Misinformation #4: Time to Act
#39 Trouble is, the natural habitats of the lesser spotted wood lice appear to be the Coalition party room, the Australian union movement, Corporate board rooms, and every climate change thread in every blog in the world. -
Bob Lacatena at 12:42 PM on 20 April 2011Clouds provide negative feedback
56, RW1,...but increased CO2 is a 'forcing'?
Yes, because water vapor responds quickly to changes in temperature. There's nothing anyone or anything can do to inject water vapor into the atmosphere and keep it there. The temperature will drop, and the water vapor will condense and things will return to normal. This is not the case with CO2, whether it is added anthropogenically or geologically. No matter how it gets there, once it does get there, it stays there for a very long time and it's effect forces the climate to follow suit. -
Bob Lacatena at 12:39 PM on 20 April 2011Clouds provide negative feedback
52, RW1, Clouds come in ahead of albedo, and behind water vapor. I'm still not quite sure how you turn this into "A very large amount (if not most) of the enhanced warming" but I'll concede the point. Clouds are an important positive feedback in the models (but not "most"). So what's your point? 53, RW1,The only true 'forcing' of the climate system is the Sun.
No. If anything, solar output is the single strongest constant in the entire system. Changes in CO2 concentrations in the atmosphere are almost certainly the primary driver as far as total change. They are tied to every major climate swing in some way, and global temperature closely tracks CO2 concentrations. Albedo is probably the primary driver as far as getting the ball rolling (and that can come from orbital forcings or aerosols -- volcanism). Water vapor and clouds are fast acting feedbacks that do not force anything on their own. But we're drifting. What is your point about clouds again? Now that you've proven that they are a strong positive feedback, why are we discussing them? -
RW1 at 12:39 PM on 20 April 2011Clouds provide negative feedback
KR (RE: 51), If water vapor is not a 'forcing' in the climate system, then how can CO2 be a 'forcing'? Are you claiming that increased water vapor in the atmosphere is not a 'forcing', but increased CO2 is a 'forcing'? This is the problem. They are both 'forcings' in the way you're using the term. The main difference is water vapor acts on much shorter time scales, but it is still a 'forcing' none the less. -
scaddenp at 12:37 PM on 20 April 2011Clouds provide negative feedback
See the IPCC report for formal definition of forcing, but it is basically something can change the radiative balance independent of temperature. Only a change in forcing can change climate. The forcing in the system are solar, GHGs (which can also be a feedback, but are a forcing if changed independently of temperature -eg by release of fossil fuel), and aerosols. On a larger time scale, changes in continent distribution and in the nature of the biosphere can alter albedo so that it is also a forcing. -
RW1 at 12:29 PM on 20 April 2011Clouds provide negative feedback
muoncounter (RE: 50), "Huh? What does that have to do with the rate at which CO2 radiative forcing increases global temperature?" I don't understand the question. Is 100 years not a significantly slower rate than hours to days? -
Bern at 12:22 PM on 20 April 2011Muller Misinformation #4: Time to Act
funglestrumpet: it does matter what's causing the warming, because the actions that must be taken are very different. If humans are causing the warming by emissions of greenhouse gases, then the obvious & most urgent action is to reduce or eliminate GHG emissions. If, on the other hand, it were all down to natural causes, then our most immediate priority would be to prepare human civilisation for the coming climate changes. The best science out there tells us that it's more than 95% likely that it's the former, not the latter, so the prudent course would be to reduce GHG emissions as quickly as possible. From a risk management point of view, I think the response to the recent events at Fukushima Dai-ichi tell the story. What's the chances of a magnitude 9 earthquake and a 14 metre tsunami hitting a nuclear power plant in it's operating life? I'd wager those odds are less than 1-in-20, even in Japan, and yet nuclear plants all around the world are scrambling to make sure they're prepared for far more unlikely eventualities. On the other hand, we've got a higher than 19-in-20 chance of climate disruption with associated human cost and massive economic losses (measured in the tens or even hundreds of trillions), and we have crowds of deniers running around shouting that we don't need to do anything, because there's too much uncertainty. Just to stray off-topic (mods, feel free to delete this last para!) - I'm starting to get quite amused how Gilles seems to post on every single thread, no matter what the topic, a comment about how we supposedly have no alternative to continuing use of fossil fuels, despite people pointing out such alternatives to him many, many times in the past. I agree entirely with the mod position: do not feed the troll. But I also agree with Tom Curtis' suggestion that trolling comments be deleted and replaced with a link to the appropriate page for that discussion. Otherwise, the trolling has achieved it's objective of diverting the reader's attention from the topic at hand, and that seriously detracts from the much more valuable discussions that appear in the comments here. -
RW1 at 12:20 PM on 20 April 2011Clouds provide negative feedback
KR (RE: 51), "From your link: "In AOGCMs, the water vapour feedback constitutes by far the strongest feedback" - followed by the lapse rate, and then surface albedo and clouds." Are you not actually reading the whole section? This not what it says (or implies). The surface albedo is the smallest feedback - closer to a third of the average cloud feedback (0.26 W m-2 °C–1 vs. 0.69 W m–2 °C–1 for clouds). The water vapor feedback is directly tied to and offset by the lapse rate feedback (1.80 W m-2 °C–1 vs. -0.84 W m-2 °C–1 for the lapse rate). " 'Water vapor and clouds act on time scales of hours to days.' Absolutely. Which why they are strictly feedbacks, not forcings." Define specifically what you mean by a 'forcing'? The only true 'forcing' of the climate system is the Sun. All the other components, such as water vapor, clouds, and precipitation, are really just responding directly or indirectly to the Sun's forcing, the net effect of all of which dictate the equilibrium surface temperature. "They cannot stay out of balance long enough to affect any other feedbacks on their own." Why not? What's keeping them from staying "out of balance"? -
Tom Curtis at 12:16 PM on 20 April 2011CO2 effect is saturated
DB, if you have been given worse in that sense, I am truly mortified.Moderator Response:[DB] Some days you're the windshield, some days you're the bug. But you can always do this afterwards:
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RW1 at 11:54 AM on 20 April 2011Clouds provide negative feedback
Sphaerica (RE 48), "Water vapor does not equal clouds." I never claimed that it did. "Again, no, clouds come in a distant fourth, at best, behind H2O feedbacks (water vapor), CO2 feedbacks, and albedo feedbacks." Not according the latest IPCC report, which says: "The water vapour feedback is, however, closely related to the lapse rate feedback (see above), and the two combined result in a feedback parameter of approximately 1 W m–2 °C–1, corresponding to an amplification of the basic temperature response by approximately 50%. The surface albedo feedback amplifies the basic response by about 10%, and the cloud feedback does so by 10 to 50% depending on the GCM." Clouds can be up to 50%, where as surface albedo is only about 10%. -
Clouds provide negative feedback
RW1 - Re: your claim that "A very large amount (if not most) of the enhanced warming from the climate models comes from positive cloud feedback." From your link: "In AOGCMs, the water vapour feedback constitutes by far the strongest feedback" - followed by the lapse rate, and then surface albedo and clouds. "Water vapor and clouds act on time scales of hours to days." Absolutely. Which why they are strictly feedbacks, not forcings. They cannot stay out of balance long enough to affect any other feedbacks on their own.
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