« PreviousContinue »
1996: *Integrated global system model for climate policy analysis: I. Model framework and sensitivity studies. MIT Joint Program on the Science and Policy of Global Change Report No. 7, 76 pgs. (with H. Jacoby, A. Sokolov, C. Wang, X. Xiao, Z. Yang, R. Eckaus, P. Stone, D. Ellerman, J. Melillo, J. Fitzmaurice, D. Kicklighter, Y. Liu, and G. Holian).
ALE/GAGE observations of CFCl3 as a test for three-dimensional tracer models. In
QELRO impacts: domestic markets, trade and distribution of burdens, and climate change. MIT Joint Program on the Science and Policy of Global Change Report No. 9, 16 pgs. (with H.D. Jacoby, R. S. Eckaus, A.D. Ellerman, D.M. Reiner, and Z. Yang).
Oceanic and atmospheric hydrocarbon measurements and sea-air fluxes during ACE-1.
*Significant influences of atmospheric transport and oceanic emissions on hydrocarbons observed during ACE-1. Trans. Amer. Geophys. Union, 77, F76 (with G. Kleiman, A. Pszenny, A. Deshpande, and X. Shi).
Impact of horizontal wind profiles on the convective transport of chemical species. Trans.
Parameterization of urban-scale photochemistry in global atmospheric models. Trans.
Mesoscale meteorological and chemical responses to aerosol radiative forcing. Trans.
Seasonal measurements of nonmethane hydrocarbons in a subtropical evergreen forest in
1997: Trends of tropospheric chlorine (1976–1996) derived from ALE/GAGE/AGAGE and
other observations. Proceedings of IGAC-SPARC-GAW Conference on Global
Interactions among emissions, atmospheric chemistry, and climate change: Implications for future trends. Proceedings of IGAC-SPARC-GAW Conference on Global Measurement Systems for Atmospheric Composition (with C. Wang).
Parametertization of urban sub-grid scale processes in global atmospheric chemistry models. MIT Joint Program on the Science and Policy of Global Change Report No. 20, 20 pgs (with J. Calbo, W. Pan, M. Webster, and G. McRae).
*Needed: A realistic strategy for global warming. MIT Joint Program on the Science and Policy of Global Change Report No. 21, 8 pgs. (with H. Jacoby and R. Schmalensee).
*Commentary: A scientist's perspective. In Proceedings ofClimate Change Policy, Economic Growth, and Environmental Quality, American Council for Capital Formation Center for Policy Research, Washington, DC, Sept. 24, 1997, in press.
An Integrated Framework for Climate Change Assessment
9/15/96-12/14/97 (15 mos)
Integrating an Ecosystems Model into a Global Change Impact
DOE & NOAA Support
The Role of Convective Clouds in Determining the Distribution of
Economics of Global Change Research
INFLUENCES ON CLIMATE SCIENCE
Chairman CALVERT. Thank you, Doctor. Dr. Spencer, you've talked in the past to what you referred to as, "influence on the climate scientists' judgment." Could you describe those for us?
Mr. SPENCER. Well, it's interesting that when science begins to work on problems that have political or religious or world-view connotations, scientists suddenly become very contentious. And I find that in this area of science that, especially the spokespersons for or against global warming theory, I think, are driven more by, oh, world-view philosophies that impact their belief on how the answers will turn out in terms of global warming. This is only human, I mean, scientists are just like everybody else, they have their own opinions on things.
Another example is, I think there are very few scientists that are qualified to make pronouncements on the big picture of whether global warming, at some level of intensity, will be significant in the next century, let's say. And, what happens is that climate change is so complex that individual scientists work on-only on-in very specialized fields and we only hear from a few spokespersons. But when the IPCC comes out and says, 2,500 scientists have agreed, now, that humans are responsible for climate change, most of the scientists-besides the fact not really being consulted on whether they agreed with that statement-most of them aren't even in a position to have a feeling for whether the big picture supports global warming or not. So, what they end up doing is they agree sort of with the status quo. You-scientists will tend to agree that other scientists know what they're talking about. So, those are a couple of things I was referring to.
Chairman CALVERT. I guess I'd like to expand on that a little bit. I-you know-scientists, to some degree, are probably no different than many of us. Sometimes outside influences, as you mentioned, can interfere with the scientific process. I think most people believe that decisions are made or opinions are made purely on scientific data that is received. Were you saying that there is also personal feelings or political thought or what-peer pressure within the scientific community on a certain line of reasoning that may be popular or the media? All these may come into
Mr. SPENCER. All these things influence the scientist's statements when he's confronted by the media.
FRAGILE VS. RESILIENT EARTH
Chairman CALVERT. That's interesting. You described a key conflict among scientists as whether they view the world as fragile or resilient. Could you expand on that for a second?
Mr. SPENCER. That's right. In fact, that's a point that was also brought out by Professor Richard Lindzen at MIT in his June 10th testimony on the Senate side. Ultimately, it seems that scientists, climate scientists or meteorologists who work in this area have sort of an unspoken assumption that the climate system is either fragile or resilient to any perturbations. I mean, obviously, the climate system perturbs itself. It doesn't need humans to do it. We've seen changes in the past, or evidence of changes, for instance, ice ages and such, but we feel either that if we poke it in one place that it will respond by developing a fever or it will poke back and adjust
for whatever perturbation you've put into the system. So, there'sand I think generally meteorologists that are trained not in climate but in meteorology tend to have the view that the climate system is much more resilient. And that's why I mentioned in my testimony that the main function of weather systems is to get rid of excess heat. It's just a statement of the Second Law of Thermodynamics and we still don't understand well enough how the system does that.
Now, early on, physicist and radiation experts were the ones that spearheaded global warming theory, let's say back in the 1960's. And they thought it was just a radiation issue, that if you reduced the cooling rate of the Earth as you pump greenhouse gases into it, that the Earth has got to warm. Well, that was-that neglected the role of weather systems and how they get rid of excess heat, and, in fact, there's still papers written today by experts in the field that neglect the influence that weather systems have on getting rid of excess heat.
SCIENTIFIC EVIDENCE FOR GLOBAL WARMING Chairman CALVERT. Thank you, Doctor. Mr. Roemer.
Mr. ROEMER. Thank you, Mr. Chairman. I'm very interested in hearing more from all the panelists on this issue. I'm certainly not a scientist by background, so I'm delighted to have experts, from across the spectrums here, to testify before our Committee. As I said in my opening statement, in 1995, the IPCC concluded that, "The balance of evidence suggests that there is a discernible human influence on global climate." Because I only have 5 minutes, and the Chairman is usually pretty strict with those 5 minutes, is the scientific evidence for human-induced global warming stronger, weaker or basically the same as it was stated by the IPCC in 1995? Stronger, weaker or basically the same? Dr. Spencer? And we'll go down the panel because I have a couple of other questions.
Mr. SPENCER. It's a difficult question to answer because a lot of us aren't sure what that statement means. It has three levels of hedging in it. It says, the balance
Mr. ROEMER. Well, instead of giving me the three levels of hedging, just give me your opinion on stronger, weaker or basically the
Mr. SPENCER. I think that considering the ambiguity of the question, all three options
Mr. ROEMER. Give me an
Mr. SPENCER. Yeah, all three. I agree with all three things you said, that
Mr. ROEMER. Stronger, weaker and basically the same.
Mr. SPENCER. And-yes.
Mr. ROEMER. Okay, that was helpful.
Mr. ROEMER. Dr. Robock. Yeah, your-he just ran for Congress with that answer.
Mr. ROEMER. I voted for you.
Mr. ROBOCK. I would say the evidence is stronger. All the work that's been done since the IPCC has found more human influences. For example, I published a paper last year showing that the verti
cal temperative structure of the atmosphere, cooling in the stratosphere, warming at the surface, was something that would not happen by chance, considering climate model output. That is something that can be explained by human impact by increasing CO2 and depleting ozone.
Mr. ROEMER. Okay, stronger?
Mr. PATRINOS. Mr. Roemer, the evidence is stronger. I have been in communication with the authors that are responsible, in fact, for the statement about the discernible influence on the global climate. These are scientists at the Lawrence Livermore National Laboratory. They were funded through my program. They tell me that recent studies that they have concluded actually confirm and further support, strengthen, the result of IPCC 95 regarding the discernible influence on the global climate.
Mr. ROEMER. Thank you. Dr. Prinn?
Mr. PRINN. Yes, well, actually, in my testimony I think I answered your question.
Mr. ROEMER. Page 5, I believe
Mr. PRINN. I believe long-termMr. ROEMER (continuing). record, if you could
Kind of answered it, but for the
Mr. PRINN. Yes. Well, I think that the human influence on climate is still unproven. Ánd, so, I would say, if you look at the 1995 report in the actual chapter 8 with all of the-where all the science was actually said, all of the necessary warnings and caveats were given. The unfortunate thing is that in the policymaker's summary, that single statement of sort became isolated from all of the caveats of the scientists and in that respect I think that it was just matter of poor communication. I still think that we're waiting to see the signal of human influence come out of the noise. At the same time, you can see from my graph, that if we're in a rapid warming sequence, then it will come out of the noise and it is extremely important that we do the research and continue the sorts of things that Ari Patrinos and Alan Robock were talking about. Mr. ROEMER. So, you say, basically the same.
Mr. PRINN. I think about the same is what it is-what my opinion was in 1995, if you like, that it's still equivocal.
Mr. ROEMER. So, we've got one all three, two stronger, and one basically the same. You-in your testimony, you quote, Dr. Prinn, now moving back the other way, that if there is the discernible path toward the higher 6 to 7 to 8 to 9 degree increase, then you have to, as you said, get your smoke detectors and your fire extinguishers ready to do something. Based on that, what recommendation do you make in terms of policy? Do you make a recommendation more in line with the Europeans? With the Japanese? With the moderate course that the United States is steering, kind of in between those three with respect to Kyoto? And I'd ask for brief questions-a brief answer to the questions so I can move back down.
Mr. PRINN. Yes, I feel that going for these modest targets by just a few countries of the world which-and these countries will not