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RW1 at 13:14 PM on 21 April 2011Clouds provide negative feedback
Sphaerica (RE: 78), "That's a gigantic if. If the moon were made of green cheese, NASA could feed the world." And you're accuse me of exaggerating things. "So you're hanging your hat on the guess that all of the climate scientists in the world got something very, very wrong... just because they admit that it's an area of uncertainty?" Not just an area of uncertainty but a significant area of uncertainty. But far from it, I'm hanging my hat on a critical examination of the evidence, data and logic - much of which I've presented here. Is it just a coincidence that whether or not sensitivity is very high or benignly low hangs mostly on the cloud feedback, and those claiming a high sensitivity are also claiming significant uncertainty for the cloud feedback, while those claiming a low sensitivity are not? Is it also it yet another coincidence that net negative cloud feedback is consistent with how the incident energy on the surface from the Sun is responded to in the system, while positive cloud feedback is not? -
Bob Lacatena at 13:12 PM on 21 April 2011Clouds provide negative feedback
79, RW1,...some calculations that are directly inconsistent with positive cloud feedback...
For the life of me, I can't figure out what the point is to all of your calculations. I can mostly follow them, but they're such a convoluted morass of numbers that I can't figure out what the final, meaningful result is supposed to be. Could you perhaps bother to actually make a point? Simply saying "clouds will be negative, look I have lots of numbers" doesn't cut it. Exactly what numbers are we supposed to take away from that mess? You also confuse matters by trying to infer things like reflectivity of clouds when inbound radiation is primarily (but not totally) in the visible spectrum, while outbound radiation leans more to LW. Reflectivity for things like clouds are dependent on the wavelength, so right there most of your calculations appear to be invalid (I say appear, because quite honestly, you present them in such a confused jumble, pulling in numbers willy nilly without clear attribution, that it's given me a headache trying to sort out what you did, and eventually I gave up... I don't have the time to sort through it if you don't have the time to present it with more clarity).These calculations are consistent with general observations - that is cloudy days are usually cooler than sunny days.
No, really? I wonder why climate scientists never thought of that.The opposite would be the case if clouds blocked more energy than they reflect away (cloudy days would be warmer than sunny days).
Again, you are ignoring wavelengths, as well as temperatures and seasons. Cloudy days in winter are warmer than summer, because of the radiation from the clouds. And as I've already explained, there are different types of clouds, with varying reflectivity. Clouds at night warm the surface while having no cooling effect whatsoever. High clouds made of ice reflect almost nothing, but trap IR. Finally, all of this is beside the point. No one has ever said that clouds can only warm, or can't reflect inbound radiation. This has all been taken into account, so your efforts to put complex numbers on it looks to me like a very well dressed strawman. What happens going forward depends on what sorts of clouds form more or less in a warmed climate. The question is, will warming generate more low clouds which reflect more than they absorb, or more high clouds which absorb and barely reflect? Your numbers do nothing to address this. Meanwhile, you completely avoided my main point, which is that many, many lines of evidence, including current observations, paleohistory and models, all point to a sensitivity of 3˚C or greater. Every one of those studies argues strongly against your inferred and mainly hoped for negative cloud feedback. You have a large body of evidence that you need to refute with something more than a pile of convoluted numbers. -
Ron Crouch at 12:26 PM on 21 April 2011Clouds provide negative feedback
If you have access you may want to refer to Observational and Model Evidence for Positive Low-Level Cloud Feedback: Amy C. Clement, Robert Burgman and Joel R. Norris (2009).Moderator Response: [DB] For those troubled by access issues, Harvard has an open copy here. -
Eric (skeptic) at 12:02 PM on 21 April 2011A Convention for Persons Displaced by Climate Change
Moderator, thanks, that answers my question about resettlement. It is targeted towards island nations and other cases with no possible mitigation measures. -
RW1 at 11:47 AM on 21 April 2011Clouds provide negative feedback
Sphaerica (RE: 71), "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." I'm I the only one who has actually read this section in the IPCC report that I linked regarding this? It clearly says the average sensitivity of the model predictions with no cloud feedback drops to 1.9 C. That is greater than half of all the enhanced warming, so I stand by my statement that clouds are a "huge" component. If the cloud feedback is negative, it would reduce the sensitivity significantly. "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." I have presented quite a bit of evidence beyond just "plain, everyman logic". In case you missed it, I started out in the thread by presenting some calculations that are directly inconsistent with positive cloud feedback, especially given the albedo has not decreased. And many other lines of evidence as well. "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." How can they claim a sensitivity of 3 C is so likely when they also claim there is great uncertainty in regards to the cloud feedback, which accounts for more than half of the enhanced warming by their own numbers. That seems like an oxymoron to me. If this were the case, the planet would never, ever cool, no matter what." How do you figure? Surely there are a multitude of other influences other than just water vapor and clouds. "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.". Water vapor is an amplifier of temperature - meaning if the temperature goes up, the water vapor goes up, and then the increased water vapor causes the temperature to go up even more and so forth. This means something other than water vapor is causing the temperature to decrease. "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." Yes, I know. I'm quite aware that the added CO2 has a 'permanent' or long-term staying effect unlike water vapor. I don't see how this contradicts anything of mine. Remember, I don't dispute a likelihood of some effect - just the magnitude. "[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." Just stating there are "no such forces" and "a simple balance" isn't even remotely good enough. If you don't know the primary mechanism (or mechanisms) that drive the current energy balance that results in such high stability, you can't accurately predict how the system will respond to any perturbation - anthropogenic or otherwise. -
Don Gisselbeck at 11:44 AM on 21 April 2011Muller Misinformation #4: Time to Act
Maybe it is time to start asking trolls if they are being paid for trolling and if not, why not. There was link “http://imgur.com/QAcJm" on RC purporting to be to a group looking for trolls. -
muoncounter at 11:34 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Eric#22: "why does the total stay the same?" I don't know, but I've seen a number of papers showing less frequent but more intense rainfall events under warming scenarios. Example: Sun et al 2007 ... the shift in precipitation frequency distribution toward extremes results in large increases in very heavy precipitation events (>50 mm day−1), so that for very heavy precipitation, the percentage increase in frequency is much larger than the increase in intensity (31.2% versus 2.4%).Moderator Response: May I draw everybody's attention to the fact that a more extended version of this piece is available on Shaping Tomorrows World. This may not answer all questions raised here, but it goes beyond this brief post which was produced for a 2-3 minute radio broadcast. -
Ron Crouch at 11:25 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
As they say, things are going to get worse before they get better. Unfortunately the global economy is so tightly tied to carbon that the addiction won't be broken for some years to come. The Alberta oil sands are evidence of this fact with them being poised to become the largest supplier of foreign oil to the U.S. So much is riding on these oil sands that they have drawn foreign investment from countries such as China and Norway. So far it's been a lot of smoke and mirrors with the environment, but what the hell, people have to have something to put in the tank of the old Hummer. What does it matter if you pollute an entire watershed and destroy the lives and livelihood of the residents of the area. Similar to the phosphate problem of the Lake Winnipeg watershed. Government doesn't get it and are ill prepared to do anything (quite often having been the cause of the problem in the first place) when the kettle gets called black. Anyone interested can view an hour and a half documentary special hosted by Canada's Dr. David Suzuki here. And that is unfortunately the tip of the iceberg. There is still a lot of coal in the ground (860,938 million tons globally) that I'm sure someone would just love to convert to gas, and then there are those oil shale deposits in the U.S. at 301 billion metric tons. Even with alternative sources of energy to drive the economy it will take time to develop the infrastructure to support them and bring them to commercial scalings, especially in the transportation sector. But it can be done, the technologies are there. So hang onto your hats because there is still a steep hill to climb before this roller coaster ride even begins it's decent. The worst part is that this roller coaster ride won't reach the point from whence it began for a very long time to come. -
Eric (skeptic) at 11:25 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
muoncounter, why does the total stay the same? In any case the cause doesn't really matter if the result is the same. The new channels will displace millions of people, far better to deal with it as a certainty but keep in mind that most people don't like being moved proactively for reasons they may not agree with. -
muoncounter at 11:16 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Eric#20: "the Indus merely behaved as it has historically." You can't really tell that from the map you linked. Another opinion: "Total rainfall stays the same, but it comes in shorter more intense bursts." In August 2010, more than half of the normal monsoon rain fell in only one week. Typically it is spread over three months. Professor Sinha remarked: "Rivers just can't cope with all that water in such a short time. It was five times, maybe 10 times, more than normal." --emphasis added As we are learning with warming, it's the abnormal rates of change that make the difference. -
Ken Lambert at 11:07 AM on 21 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
Typo "random walk" -
Ken Lambert at 11:07 AM on 21 April 2011The e-mail 'scandal' travesty in misquoting Trenberth on
Alec Cowan #145,146 Not a number or reference to any new OHC research in either of you posts Alec. I can only assume that you don't have any facts to argue and are engaged on a rambling randon walk through the topic. -
muoncounter at 11:03 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
Bern#14: "the 'skeptic' approach" I like the ones who say 'I can't see it happening, so it must not be real.' In the car/wall analogy, they're driving with their eyes closed. -
Eric (skeptic) at 10:46 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Here's a picture of the courses of the Indus from "The Recent History of the Indus" by D. A. Holmes ($10 from JSTOR) http://i433.photobucket.com/albums/qq51/palmer2/indus-courses.jpg that shows why millions of people were affected - the Indus merely behaved as it has historically. -
adelady at 10:33 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
If we're talking environment / climate change refugees, we have to face the truth about where people live and why they live there. River deltas, low land beside the ocean and flood plains - why do people live there? The land is fertile because of silt deposition. Catching fish is much easier if you live close to the river or the ocean. The reason there _will_ be many, many more environment refugees is because the places that are easiest or best for people to live are the most vulnerable to sea level rise and to flooding from extreme precipitation. And already there are many people dispersing from drought affected lands, including those whose glacier fed water supplies are drying up - South America being a prime example here. In my view the number of affected people is not the issue. The big issue is the year. 2050, 2065, 2040? That is the real question. -
Rob Honeycutt at 10:24 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
"{DB} More like ramming speed." Was that Charles and David Koch running the ship? Charles in the chair and David on the drum. (Sorry, couldn't help myself.) -
Bob Lacatena at 09:50 AM on 21 April 2011Clouds provide negative feedback
61, RW1, Somehow I missed this one: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.
That's a gigantic if. If the moon were made of green cheese, NASA could feed the world. So you're hanging your hat on the guess that all of the climate scientists in the world got something very, very wrong... just because they admit that it's an area of uncertainty? Except that their estimates are not based on guesses, they're based on science. All you've offered to support a contrary view is conjecture. -
Bern at 09:50 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
Nick, I rather think that was BKsea's point. :-) Whereas the 'skeptic' approach is more "damn the torpedoes, full speed ahead!" Actually, for a lot of them, it's more like "It's not going to be a problem until after I'm dead, so what do I care? I'm making my millions now, whatever it takes!"Moderator Response: [DB] More like ramming speed. -
Tom Curtis at 09:33 AM on 21 April 20112nd law of thermodynamics contradicts greenhouse theory
LJRyan @1007, I apologize for my description being confusing. Just to make sure we are on the same page: The plates are perfect thermal conductors, so therefore position and length of the heating elements is irrelevant; The heating elements are such that, plugged into mains power, each draws 480 Watts of power, and with no losses else where, ie, each receives 480 Watts heating (and please note, that is 480 Watts, not 480 Watts/meter^2). Given these clarifications, does your answer change, and if yes, to what? You asked why Surface radiation stops at 480 rather than a higher value. The simple answer is that if Surface radiation goes above 2*S, or AtmUp, or AtmDn goes above S, then the system losses more energy than it gains, and therefore cools. The easiest way to see this is with the spread sheet models discussed some 400 posts backs. Rather than try to find that discussion again, I have done up another spread sheet. Column A is the Step; Column B is S (energy in); Column C is Surf; Column D is AtmUp (energy out); and Column E is AtmDn (recirculated energy). Row three contains the initial values, which for S(Column B) is always 240 in three "experiments" that I conducted. In my three experiments, the initial value for Surf (Column C) was 0 for the first two experiments, and 1000 for the third. The initial values of AtmUp and AtmDn (Columns D and E) where 0 for the first and third experiments, and 500 for the second. The formulas for each of steps 2 to 100 where: In column B: =the value in column B for step minus 1 (=B3) In column C: = the value for column B and the value for column E for step minus 1 (=B3+E3) In column D: = (the value in column C in step minus 1)/2 (=C3/2) In column E: = the value in column D in the current step (=D5) The values in brackets are the actual formulas from my spread sheet for row 4 (the second step). The results for each of the three experiments above on step 60: Column A (Step) : 60 Column B (S) : 240 Column C (Surf) : 480 Column D (AtmUp): 240 Column E (AtmDn): 240 So, regardless of the initial conditions of the Surface or Atmosphere, in this model after a short number of steps the outgoing energy will equal the back radiation will equal the incoming energy; and the surface radiation will equal 2 times the incoming energy. You said equilibrium will be reached without back radiation being absorbed. Well, first note that in this model there must be back radiation because the "atmosphere" has an emissivity of 1 in IR wavelengths. Second, the back radiation must be absorbed because the surface has a blackbody. But even if the surface has an emissivity of less than 1 in the IR spectrum, the radiation from the surface to the atmosphere will be equal to the incoming solar radiation plus emissivity times the back radiation plus (1-emissivity) times the back radiation. That is, the radiation from the surface will equal the solar radiation plus the absorbed back radiation plus the reflected back radiation, which is to say the equilibrium point will be identical, although we may wish to relabel some components of the model. Of course, this result obtains only so long as the emissivity of the surface is not so low that the spectrum of its radiation is not forced into the range of the spectrum to which the atmosphere is transparent. Also obviously, the surface temperature will be higher with emissivity < 1. With respect to the idealized greenhouse model it is the next step in complexity of atmospheric models from a simple grey slab model. It is still inaccurate as a representation of reality, but useful for exploring concepts. I have not yet checked the maths on the Wiki page, and will comment on it as need in the discussion. -
Eric (skeptic) at 09:30 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Even if the floods in Pakistan were due to AGW, it is going to be problematic to "preemptively resettle" people at risk. It is far better to install flood prevention because floods also occur naturally, including really large floods A 5000-Year Record of Extreme Floods and Climate Change in the Southwestern United States -
Berényi Péter at 09:18 AM on 21 April 2011Christy Crock #4: Do the observations match the models?
Just to make things clear for everyone. CMIP3 is neither a model nor a collection of models, it is Phase 3 of the Coupled Model Intercomparison Project. We are currently at Phase 5 (Phase 4 was skipped for some reason). There are modelling groups who participate in this joint project.Moderator Response: [Dikran Marsupial] This seems somewhat pedantic. It is perfectly reasonable English usage to refer to the collection of models used to compile the CMIP3 simulation archive as the "CMIP3 models", even though the CMIP3 project only archives the results of model runs rather than the models themselves. The archive implicitly defines a collection of models. -
Nick Palmer at 09:05 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
BKsea @ #8 The slower you're going when you hit the wall, the less damage you'll do. I think any one in their right mind would take their foot off the accelerator, slam on the brakes and see if there's any anchors in the boot to throw overboard. Use whatever it takes to hit the wall as slowly as possible. -
Marcus at 09:03 AM on 21 April 2011Muller Misinformation #4: Time to Act
BillyJoe, if this site was *really* trying to create some kind of rigid conformity in viewpoint, then do you *honestly* think that the posts by people like BP, HumanityRules, RSVP, John D or Poptech would be allowed to stand? Heck, the moderators even allowed Poptech to rant about his beloved "list" for more than 10 pages-hardly the actions of people trying to silence dissent (though there was something quite hilarious in watching Poptech defend the indefensible-in an increasingly desperate manner). The fact, though, is that Gilles seems to be deliberately trying to sabotage threads by dragging every single discussion back to his beloved "the world can't survive without Fossil Fuels" meme. -
Marcus at 08:54 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
The thing I hate is the obvious *lie* in Tony Abbott's comment here: "To make not a scrap of difference to the environment any time in the next 1000 years." Tim Flannery didn't claim it wouldn't make a scrap of difference in the next 1000 years-only that it wouldn't cool the planet for another 1000 years. It will make a huge difference over the next 100 years though-the difference between about another 1 degree of warming vs as much as 4 to 6 degrees of warming. -
michael sweet at 08:39 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Harry: James Hansen says that the floods in Pakistan would "almost certainly not" have occured if not for AGW. You need to provide evidence that these extraordinary floods are not caused by AGW. If floods caused by AGW destroyed their houses these refugees are climate refugees. Likewise farmers whose crops fail because of AGW who move are climate refugees. Katrina went over an abnormally warm batchof water just before it hie NEw Orleans. It is impossible to know how powerful it would have bee nwithout AGW. By claiming proof is required for attribution of weather events you are denying hte reality of what has been observed. -
ranyl at 07:51 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
"HadCM3LC simulates very low rates of decline in atmospheric CO2 concentration. Mean (regressed) rates of change for the following hundred years are predicted as −0.2 ppm y−1, −0.4 ppm y−1 and −0.75 ppm y−1" Environ. Res. Lett. 4 (2009) 014012 (9pp) doi:10.1088/1748-9326/4/1/014012 How difficult is it to recover from dangerous levels of global warming? J A Lowe1, http://iopscience.iop.org/1748-9326/4/1/014012/ And this is with a good carbon cycle model which includes loads, N ferilization effects, but not increased pests, fires, sea level rise vegetation loss, permafrost releases and eco-system loss effects from all human's other practices... Interesting times ahead. -
andthorne at 07:42 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
The Aussie is smart He knows that it is methane oxidation that is causing all the extra CO2, and methane emmissions come from enhanced oil recovery, which the Austrailain government has no intendtion of stopping it is also methane hydrates that are bring all the heat up to the surface of the earth, as well as kill sea life. -
scaddenp at 07:24 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Harry, all over the world there are cities, infrastructure that are vulnerable for a host of reasons, good and bad. Climate change will convert a higher proportion of these vulnerabilities into crisis every year than if we did not have climate change. I remain disappointed that you didn't answer the question at bottom of this post. I am genuinely interested in what your response would be. It would also give me some assurance that you don't belong the "climate science must be wrong because believing it would mean taxes/agreeing with Al Gore/environmentalists/world government" crowd. -
scaddenp at 07:07 AM on 21 April 2011Muller Misinformation #4: Time to Act
BillyJoe - John's site. John's rules. I like them. He stated that his intention for creating the site was a "one stop shop" for climate arguments. The discussions are supposed to illuminate the articles on the argument. Long diversions are useless to someone coming to the site to learn. Any number of places on the internet where you can have rambling discussions on climate. -
Albatross at 06:47 AM on 21 April 2011Christy Crock #4: Do the observations match the models?
Alec @45, Good points-- more deception by omission by the 'skeptics', go figure. I think people need to remember that if the errors in albedo in the models were so horribly wrong as some are trying to suggest, there is simply no way that they would be performing so well at predicting and reproducing the temperature record, which is after all the net result of many processes, including the important role of albedo. Also, if one uses the ERBE data to reflect the planetary albedo in the bender paper, six the models actually do quite well. With that said, as far as I know, there is no obvious reason to choose ERBE over CERES, although there may be versions of each satellite dataset which include superior corrections than others. The marked difference between the two observation platforms is disconcerting though. That Bender paper sure is obscure. There are two new papers on this issue that may be of interest, one by Bender that that has been submitted to J. Climate and another hot off the press by Donohoe and Battisti (2011, J. Climate). Here is their abstract with my highlights: "The planetary albedo is partitioned into a component due to atmospheric reflection and a component due to surface reflection by using shortwave fluxes at the surface and top of the atmosphere in conjunction with a simple radiation model. The vast majority of the observed global average planetary albedo (88%) is due to atmospheric reflection. Surface reflection makes a relatively small contribution to planetary albedo because the atmosphere attenuates the surface contribution to planetary albedo by a factor of approximately three. The global average planetary albedo in the ensemble average of the CMIP3 pre-industrial simulations is also primarily (87%) due to atmospheric albedo. The inter-model spread in planetary albedo is relatively large and is found to be predominantly a consequence of inter-model differences in atmospheric albedo, with surface processes playing a much smaller role despite significant inter-model differences in surface albedo. The CMIP3 models show a decrease in planetary albedo under a doubling of carbon dioxide – also primarily due to changes in atmospheric reflection (which explains more than 90% of the inter-model spread). All models show a decrease in planetary albedo due to the lowered surface albedo associated with a contraction of the cryosphere in a warmer world, but this effect is small compared to the spread in planetary albedo due to model differences in the change in clouds." Two important take home points here: 1) The planetary albedo from the CMIP3 simulations agree very well with the observations. 2) The CMIP3 model simulations suggest a positive water vapour feedback fro doubling CO2, not a negative feedback. -
Dan Moutal at 06:36 AM on 21 April 2011How I lived through a carbon tax and survived to tell the tale
There is some risk, but I am not convinced it is significant. There have been a few reports that claim we already have all the tech we need to move away from FFs. What we need then is a massive deployment effort. But even if I am wrong, it is hard to imagine that any risk management policy would state we should avoid the possible risks of moving off FFs and condemn ourselves to the massive risks of climate change. -
Albatross at 06:28 AM on 21 April 2011Christy Crock #4: Do the observations match the models?
BP @43, First, and foremost I prefaced my comment with 'IIRC'. Perhaps you are not familiar with that jargon. It means "If I recall correctly", or "If I remember correctly". I think we can agree that your reference to 'basically the same' is an accurate reflection, although as Alec points out, it may be that some of the model configurations may have changed. Anyhow, I do not think it is worth deliberating this particular point further. -
Albatross at 06:20 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
Jay @3, Err, this is my first post on this thread. -
BKsea at 06:17 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
your car is shooting toward a wall at 100 kph and your foot is depressing the accelerator to the floor. Even if you slam on the brakes, you will not stop in time. Should you take your foot off of the accelerator? -
les at 06:02 AM on 21 April 2011It's aerosols
Just in case anyone's still interested in this. A new video of Hansen discussing aerosols, models, sea rise etc. http://climateprogress.org/2011/04/20/hansen-sea-level-rise-faustian-aerosol-bargain/ via ClimateProgress a good watch. -
Alec Cowan at 05:59 AM on 21 April 2011Christy Crock #4: Do the observations match the models?
@Albatross #38 About the error bars, Bender et al showed first this graphic:
where the objections are not applicable. And then they showed their figure which BP used as the basis of his/er prêt-à-porter objections about models. In that figure values are de-seasonalized. Here the same figure with some retouches for later use:
The first time I read de-seasonalized in that paper my first instinct was thinking why is it de-seasonalized and later I saw the period (Feb 1985 - May 1989), but even then I thought why is it so much difference. The question is why is it de-seasonalized (not because "de-seasonalized is gooooood") and how is it de-seasonailized. I'll get back to this in a later post (of course BP's comments don't deserve such attention, but I have half a dozen of papers analyzed this way so I can provide fresh exercises to our students)
On the other hand, in spite of BP's forgettable answer, I think that you could be talking about that group include a few models developed during the '90s, and probably used in the Third Assessment though included again in the Fourth one to show a connexion.
I use to teach that what is absent is as important as what is in front of your eyes. Bender's uses hindcasts to that period -not including an exact number of years- but, what about the same analysis for a period closer to the time of the paper, as a hindcast or as a forecast? No mention of that in the paper.
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L.J. Ryan at 05:07 AM on 21 April 20112nd law of thermodynamics contradicts greenhouse theory
Tom Curtis 1006 1) Assuming the constraints as outlined, the temperature for both plates is solely based on heating element. Your heating element description is a bit muddled. That is, power = current^2 x resistance...so "480 W current" is a bit confusing. Does the wire run the entire length of each plate? Or is the element the same for both, only the plate dimensions different. Going with the identical heating element scenario, and assuming plate surroundings are of lower temp then plates both plates radiate 480W/m^2...303K. 2) No violation, other then the fantastic assumptions. You said: "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." Then what would stop the surface from absorbing the next cycle of re-radiation and increase emissions further? Why does it stop at 480 and not 720 or 960 etc.? You said: "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." But Tom, back radiation need not be absorbed for equilibrium. Nor for entropy to increase. As I demonstrated in 1004, system equilibrium is reached without back radiation. Let me try a different approach, do you agree with Idealized greenhouse model? -
grypo at 04:30 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
It's interesting to discuss, but, as RC notes, the scenario is not realistic and, as CB notes, not a choice that's on the table, nor will it be anytime soon. -
Charlie A at 04:18 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
In regards to floods,here is some interesting commentary on actual observations about floods and stream flows versus the perception. It has links to other technical presentations and peer reviewed literature. Per a recent presentation at the European Geosciences Union general assembly earlier this month, "Despite common perception, in general, the detected trends are more negative (less intense floods in most recent years) than positive. Similarly, Svensson et al. (2005) and Di Baldassarre et al. (2010) did not find systematical change neither in flood increasing or decreasing numbers nor change in flood magnitudes in their analysis." ref: http://itia.ntua.gr/getfile/1128/2/documents/2011EGU_DailyDischargeMaxima_Pres.pdf Science works with observations. Politics works with perceptions. -
CBDunkerson at 04:16 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
Yes, as BBP notes there would be a relatively 'quick' (i.e. over the course of a few decades) decrease in atmospheric CO2 levels if we stopped emitting entirely. The amount of this 'draw back' is still subject to some debate, but the estimates I've seen have generally been less than 50 ppm (some much less). However, since we aren't anywhere near stopping all CO2 emissions and none of the major emitters have even begun programs which could eventually get them there... this doesn't seem likely to be relevant any time soon. Even the 'constant at 2000 levels' figure on the graph is now impossibly optimistic... we're already well past that and have no chance of returning to it soon. -
Lassesson at 04:00 AM on 21 April 2011David Evans' Understanding of the Climate Goes Cold
Lassesson #5, 15 Sphaerica #7 dana1981 #12, 16, 24, 36 Nick Palmer #23, 26 Surprice! The same skeptic argument that I thought Evans was making is now available with a rebuttal here at SkS - CO2 limits won’t cool the planet. Aparently, that was not what Evans was talking about (even if it can be misinterpreted that way - if that was intentional or not, I don't know). Instead he was referring to the same argument as Mr Monckton did in his myth #15 when he said that "CO2 limits will make little difference". This is often referred to as Tragedy of the commons where one individual can argue that his/her contribution will not matter, since there are too many others that will have to make the same contribution to have an effect. I propose that we continue this discussion in the blog post or the rebuttal connected to "CO2 limits won’t cool the planet", if we have anything more to say about it. -
BBP at 03:52 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
Actually, cutting all emissions would have a short term effects, see this at RealClimate Climate Change Commitment II . First, temperatures would rise as aerosols emissions would stop as well as well, then there would be a steady decline as CO2 began to get drawn out of the atmosphere. The graphic in this article assumes constant concentrations. -
Stephen Baines at 03:45 AM on 21 April 2011The 5 characteristics of scientific denialism
This is an interesting article. I am not inclined to believe that conservatives and liberals differ fundamentally (or at last not monolithically) in their ability to accept science. Conservatives were, for example, at one point very important in the US conservation movement, the EPA etc. What's clear is that climate science is currently caught in a larger political narrative at present that largely swamps the scientific narrative. That's one reason most scientists won't participate in this debate -- they don't have a clue what the script is and they're aware enough to realize it. It's like that nightmare when you find yourself on a stage acting in a play and you have no idea how to respond to the cue someone feeds you because suddenly the play has changed. It goes both ways, non-scientists exposed to the scientific narrative can't recognize the storyline and are immediately lost when confronted with the reams of literature out there. So they retreat into the narative they're comfortable with, which looks something like they see on ESPN...two teams banging it out. It does seem that the modern Republican Party (of the last couple decades) has shifted to an outright rejection of science as a mediating influence over policy. Personally, I think this shift is related to the adoption of PR mechanisms borrowed from marketing, which explicitly work on the native tendencies Chris Mooney is writing about. Such methods require messages that are simple to deliver and that target people's sense of identity. Nuance is not an advantage, so science becomes a hindrance really. Eventually, it's just been left out altogether so as to fashion efficient messages implying threat from some anonymous group or another. The circling of the wagons - the brand loyalty, if you will - that results is a real firewall against big losses politically. If those in the wagons have cash, all the better for the party in question - especially now that money is equated to speech in the US! It's a very rational to adopt such an approach from the point of view of politics. Of course, nature could care less what works in politics. I'd argue that undercutting science as the Republicans are doing is ultimately very bad for the very business interests they claim to support. -
Harry Seaward at 03:43 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Michael Sweet @ 8 You need to prove your statements. How did AGW create the climate refugees? Just sticking with New Orleans (and I assume you are talking about Katrina), that issue had nothing to do with AGW. It had everything to do with a city built below sealevel and protected by dikes and levees. The pumps and levees were not maintained properly due to a corrupt local and state government. They were also not designed to cope with a storm surge the size of what Katrina brought in. Now there is an environmental component and that is the loss of wetlands that served as a buffer and "sponge". The loss can be attributed to the creation of canals which accelerated water flow and did not allow the deposition of sediment. -
muoncounter at 03:41 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
Cadbury#3: "extremely difficult to get out, and have long-term consequences."" What is the difference between the above quote and your rejoinder "gradually suck all of the co2 out of the atmosphere, although it took quite a long time"? -
Dr. Jay Cadbury, phd. at 03:36 AM on 21 April 2011CO2 Reductions Will Not Cool the Planet? We Know
@Albatross "for once in the atmosphere, they are extremely difficult to get out, and have long-term consequences." I submit that this is false because the oceans did gradually suck all of the co2 out of the atmosphere, although it took quite a long time. I think it is more accurate to say that it is hard to get co2 out of the atmosphere over a short period of time. -
Bob Lacatena at 03:13 AM on 21 April 2011Clouds provide negative feedback
72, RW1,...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.
Can you provide examples of specific forcings that have occurred in the last century (or millenium), to which the climate has resisted change? -
Dan Olner at 03:09 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Hmm, slight cop-out answer on my part there... I think a) measuring the number of environmental refugees is entirely feasible (with whopping error bars, but useful numbers can be arrived at) b) that's more useful than trying to work out 'climate refugee' numbers, since that would involve the double whammy of attributing climate effects to environmental problems (OK in aggregate over large timescales, much more problematic for e.g. specific droughts) and then deciding who counted as a refugee. That doesn't change the fact that in aggregate, environmental refugee numbers will massively increase due to climate change - I just can't see how you can do anything but estimate crude aggregates over time. But that's an uninformed opinion, and it'd be good to hear from people more familiar with the attribution literature. I've only read Myer's original 1995 stuff and a few follow-ups: that was mainly about giving the environmental refugee problem international attention, AFAIK. I don't know what the state of the art is in estimation... -
Dan Olner at 02:49 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Charlie A: fair enough. Handily, I actually had a go at answering that in response to Michael Sweet - comment 10. Short answer: I don't know, and it seems like a steep proposition to me, but I'd like to know what more knowledgeable people than me have to say on the matter. -
Charlie A at 02:42 AM on 21 April 2011A Convention for Persons Displaced by Climate Change
Dan Olner says "Charlie A: I'm sorry - have you got a link to a UNEP article saying anything about "200 million climate change migrants by 2050"? I can't find one. And did you read my comment about the difference between 'environment' and 'climate?'" I didn't say that there is a UNEP article predicting "200 million climate change migrants by 2050". As I stated in my comment above, the phrase "200 million climate change migrants by 2050" is taken from the article by David Hodgkinson to which these comments are attached. My question is an attempt to clarify the meaning of what this Skeptical Science article intends to convey. One way of clarifying what the Skeptical Science articles reports is to ask whether the 20 million persons displaced by floods in Pakistan would be counted towards the 200 million climate change migrant count, if the floods had taken place in 2050. Michael Sweet states "20 million people in Pakistan had their homes and livelihoods destroyed by AGW". So it is clear that at least for Michael Sweet, they would be counted a refugees from anthropogenic global warming. -------------------------------- Dan --- let's step back and start over. These comments are attached to a Skeptical Science article by David Hodgkinson. A key section of that article reads "The existence and scope of such displacement are often established by reference to the likely numbers of displaced people. The most cited estimate is 200 million climate change migrants by 2050 or one person in every forty-five." My question is whether the 20 million displaced by the Pakistan floods, or the 4 million still homeless would, in your understanding of the claim, be included in the definition of "climate change migrants".
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