From	Kevin Trenberth	Date	Fri, 12 Mar 2004 11:22:56 -0700
To	Tom Crowley
CC	Chick Keller, Richard Somerville, Tom Wigley, Howard Hanson, LDRD, James Hansen, Michael Schlesinger, Phil Jones, Thomas R Karl, Mike MacCracken, Ben Santer, Ellen Mosley-Thompson, ray bradley, Malcolm K. Hughes, Keith Briffa, Tim Osborn
Subject	Re: REQUEST FOR INFORMATION ON CLIMATE CHANGE AND HUMAN ATTRIBUTIONS
I agree with Tom: I sent you (without copying others) a whole host of material.. Kevin tom crowley wrote: > For goodness sakes, I don't know where to start - let me just make one > point with respect to solar - solar projects onto the GHG signal in > the 20th c. so solar cannot be distinguished during that time. if one > were to independently correlate solar and GHG with temp. since 1750, > solar would "explain" about 75% of the variance, GHG about 70% - a > spectacular 140% of the variance explained! > > the only way to evaluate solar is to look at intervals when GHG was > not changing and solar was - the preanthropogenic interval - perhaps > the most comprehensive evaluation of the solar effect is in the > attached paper, where it is quite clear that solar effect is either > negligible or just barely significant, ie., 5-10% of the decadally > scaled variance. > > with respect to the MWP all you have to do is plot the data up and > compile them - the numbers don't work out as being warmer than the > present - at best approaching or slightly exceeding mid-20th c. the > reason is that is was warm at different times. Soon and Baliunas of > course never showed this - but if you actually look at the damn data > and plot up, the same answer as I stated above keeps showing up, over > and over. > > with respect to UAH, there are now two other reconstructions that show > otherwise. > > enough, this is like trying to convert someone with one religion to > another. > > tom > > Chick Keller wrote: > >> Richard and Friends, >> >> thanks for the point of view. I'll put some of this into my >> presentation. >> >> However, it won't wash when facing critics head-on. >> >> Their latest arguments are more subtle. Their main point is that >> their counter information hangs together into a logically coherent >> picture. >> >> Models: no real finger print that distinguishes AGHG forcings from >> others! Models using AGHG forcings predict warming is function of >> latitude yet the Arctic is hardly warming (north of ~^65°N), and high >> latitude Antarctic (excepting for the peninsula) is actually cooling >> slightly. >> >> Models: As you say need AGHG forcings to simulate last 30 years of >> observed warming. But, they counter, UAH satellite reductions show >> no such warming so don't need AGHG forcing (or at least don't need >> effects of positive feedbacks and just increases in AGHGs don't cause >> so much warming). >> >> Solar forcing--not able to generate last 30 years of observed >> warming. Same counter as last one--"See, they say, no increased >> solar in last 25 years is consistent with no warming!! >> >> Also, since no warming since 1945, MWP most likely to have been as >> warm as now and thus sun can indeed explain (with proper lags) >> observed warming thus far. >> >> Their model--climate varies depending on solar activity. all >> observations are consistent with this. >> >> Models predict that any surface warming will be seen in the >> troposphere. Since UAH satellite reduction shows no such warming--1. >> models are wrong and/or no warming at surface just lousy observations. >> 2. If no warming at surface in last 30 years AGHG forcing predictions >> by models is incorrect probably due to poor cloud/water vapor >> modeling--no positive feedbacks to speak of. >> >> Sooooo, you can say all you want that all the prestigious societies >> and folks say it's AGHGs, but they've been bamboozled by a few of >> elitist scientists. As long as satellites show no recent warming, >> the entire AGHG hypothesis collapses, not because multi-atomic >> molecules don't cause the atmosphere to be more opaque, but because >> there are no positive feedbacks which the models need to get the >> "right" answer. >> >> So, what I need is strong evidence that the surface record is indeed >> correct (UHI effect is small, and marine boundary layer approximation >> is correct). >> >> Now, Richard, toss in large effects of land use changes and of black >> soot forcing changing earth's albedo, and you now have additional >> forcings which may be causing warming but can't be countered by >> reducing AGHGs. >> >> Soooo, it still ain't all that easy to convince an audience that the >> Singer's of this world aren't on to at least part of the problem. >> >> AND keep in mind that increased CO2 is good for us--more agriculture, >> etc. >> >> Nope it just ain't that easy. So any information--graphics, etc on >> these issues will be greatly appreciated. >> >> Regards to all, >> chick >> >> >> Hi Chick and friends, >> >> Good to hear from you, Chick. I'm busy, like all of us, and >> responding to Singer is not my cup of tea, so I'm glad you and others >> are willing. I hate to be in the same room with him, frankly. He's >> a third-rate scientist and is ethically challenged, to say the least. >> >> From others on your email list, I am sure you will receive tons of >> useful information. However, I think your entire basic strategy for >> confronting Singer might not be optimal. Sometimes the most pressing >> issues in the research community, or the most interesting questions >> scientifically, are not necessarily the best ways to carry on the >> public conversation. I am thinking in particular of your statement: >> >> "Perhaps the most important is that satellites don't show much >> warming since 1979 and disagree substantially with the surface >> record, which must then be incorrect. Were we able to resolve this >> conundrum, I think most of the other objections to human generated >> climate change would lose their credibility." >> >> For what it's worth, here's my take on your approach. I >> respectfully disagree with you that hammering away on reconciling the >> MSU data with radiosonde and surface data is the right way to go in >> dealing with the Fred Singers of the world. Even though much of the >> differences may now be apparently explained, it's still a terribly >> messy job. The satellite system wasn't designed to measure >> tropospheric temperatures, the calibration and orbital decay and >> retrieval algorithm and all the other technical issues are ugly, and >> nobody knows how much the lower stratospheric cooling ought to have >> infected the upper troposphere, among other points one might make. >> >> No matter what one does on trying to make the MSU data tell us a >> clean story, there are remaining serious uncertainties. That's >> basically what the NAS/NRC study chaired by Mike Wallace concluded, >> and it's still true, in my view. Plus the data record is so short. >> In addition, as you say, you are retired, and research on these >> things is not what you have first-person experience with, so when you >> try to study up on the latest published results, you're at a >> disadvantage compared with the Singers of the world, whose full-time >> job is to cherry-pick the literature for evidence to support their >> preconceived positions. >> >> One of the tactics of the skeptics is to create the impression among >> nonscientists, especially journalists, that the entire science of >> climate change rests on the flimsy foundation of one or two lines of >> evidence, so that casting doubt on that foundation ought to bring >> down the entire structure. For temperature, that approach is clearly >> behind the attacks on the "hockey stick" curve over the last 1,000 >> years or the satellite vs. in situ differences over the last 25 >> years. Refuting the errors of the papers by Soon and Baliunas or by >> McIntyre and Mckitrick doesn't faze these people. They just shift >> their ground and produce another erroneous attack. Their goal is not >> to advance the science, but to perpetuate the appearance of >> controversy and doubt. >> >> I don't think the skeptics should be allowed to choose the >> battlefield, and I certainly don't think the issue of whether >> anthropogenic influences are a serious concern should be settled by >> looking at any single data set. I do think the IPCC TAR was right to >> stress that you simply can't plausibly make GCMs replicate the >> instrumental record without including GHGs (and aerosols). I also >> think the recent AGU and AMS public statements, which you will >> doubtless find on their web sites, are right on target. Many of us >> were pleasantly surprised that our leading scientific societies have >> recently adopted such strong statements as to the reality and >> seriousness of anthropogenic climate change. There really is a >> scientific consensus, and it cannot be refuted or disproved by >> attacking any single data set. >> >> I also think people need to come to understand that the scientific >> uncertainties work both ways. We don't understand cloud feedbacks. >> We don't understand air-sea interactions. We don't understand >> aerosol indirect effects. The list is long. Singer will say that >> uncertainties like these mean models lack veracity and can safely be >> ignored. What seems highly unlikely to me is that each of these >> uncertainties is going to make the climate system more robust against >> change. It is just as likely a priori that a poorly understood bit >> of physics might be a positive as a negative feedback. Meanwhile, >> the climate system overall is in fact behaving in a manner consistent >> with the GCM predictions. I have often wondered how our medical >> colleagues manage to escape the trap of having their entire science >> dismissed because there are uncured diseases and other remaining >> uncertainties. Maybe we can learn from the physicians. >> >> People on airplanes, when they find out what I do for a living, >> usually ask me if I "believe in" global warming. It's not religion, >> of course. What I actually tend to believe in, if they really wanted >> to try to understand, is quantum mechanics. CO2 and CH4 and all >> those other interesting trace gases have more than two atoms, and >> that fact simply has inescapable consequences. You just can't keep >> adding those GHG molecules indefinitely without making the atmosphere >> significantly more opaque in the IR. The "debates" in the reputable >> research community are all quantitative. If skeptics don't worry >> about doubling, they ought to be pressed to tell us why they are >> unconcerned about tripling or quadrupling or worse. That's where the >> planet is headed. The fact that remote sensing and model building >> are hard work, and that much remains to be done, shouldn't be allowed >> to obscure the basic obvious facts. >> >> Bonne chance et bon courage, >> >> Richard > > -- **************** Kevin E. Trenberth e-mail: trenbert@ucar.edu Climate Analysis Section, NCAR www.cgd.ucar.edu/cas/ P. O. Box 3000, (303) 497 1318 Boulder, CO 80307 (303) 497 1333 (fax) Street address: 1850 Table Mesa Drive, Boulder, CO 80303