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amount of ocean that has to be warmed up or cooled off and if you-and it takes a while to warm it off-warm it up and it takes a while to cool it off and those physics are included in the models.
VARLABLES IN CLIMATE MODELS Mr. COBURN. I guess my question is, do we know all the variables?
Mr. ROBOCK. Well, the model
Mr. COBURN. It's not whether or not we include them, it's do we know the
Mr. ROBOCK (continuing). — Like you said for a human being, the climate system is much more complex than the representation that we have in our current models. As we continue to study it and make the models more complex and more realistic, they represent the climate system in a more realistic way.
Chairman CALVERT. Mr. Coburn, we'll be able to come back on a second round interval. Thank you.
Mr. COBURN. Thank you.
DEFORESTATION Ms. HOOLEY. Thank you, Mr. Chairman and thank you, panel members. I have a couple of questions. Being from the northwest where we're very proud of our national forests, where they provide both recreational and economic opportunities, I'm concerned about the relationship between our forests and the Earth's climate. Mr. Patrinos, or other members of the panel, as the results of your global circulation models with respect to forests, can you tell me what extent your models show that deforestation causes global warming? And, subsequently, do you have research that shows the effects of global—what global warming could be on our forests' productivity?
Mr. PATRINOS. Certainly deforestation is one of the sources of carbon dioxide in the atmosphere which is a greenhouse gas and, thus, through that, adds to the greenhouse warming. With respect to the impact of climate change on deforestation, we know that there would be significant changes in precipitation patterns, as I said in my written—in my oral remarks. However, our understanding of impacts at the regional level is still pretty fragmentary. We know, however, that there will be some forests that will migrate to the north, some trees that will move successfully to the north, others that will not be able to do this northern migration. So, in a sense, from our best estimate with respect to the impacts of climate change on forests, it would be that the mix of trees across the Earth will be fairly—will be different than it is today. Whether this is a benefit or a negative impact is something that remains to be seen and analyzed with the more detailed models that we're developing down the road. Ms. HOOLEY. Anyone else want to comment?
Mr. ROBOCK. Well, cutting trees down, deforestation, is about a fourth or a fifth of the contribution now to the CO2 in the atmosphere. And so, it's contributing to the global warming. There will be a response. More CO2 in the atmosphere presumably makes trees grow a little bit more but if the climate changes so much that they can't exist in their current environment, they'll die and there's a question as to whether they can move, whether new areas might not have the right soils, might not be so that trees might not grow there. So, there will certainly be change in the forests as a result of climate change.
Ms. HOOLEY. Yes, Dr. Prinn?
Mr. PRINN. Yes, we actually have an ecosystem model as a part of our modeling system. It-first, increasing CO2 does provide a fertilizer for photosynthetic activity and so the predictions of this model for natural ecosystems is a globally aggregated—the total net primary production by the biosphereby the land biosphere increases. Despite the fact that there's, in fact, some warming and, in some regions, detrimental climate change, in the global aggregate, it is positive. The issue of the changing nature of ecosystems is one that the current models of ecosystems are just beginning to sort of move into that area to try to get predictive capability to say, you know, how will an actual ecosystem type change with time? And that capability is not yet in our model so I can't comment on things that might take hundreds of years whereby aboreal forest becomes a deciduous forest and so on. I think the research there is extremely important but it's sort of only beginning. So, we don't have much of an answer for your question, I don't think.
TECHNOLOGY IN CLIMATE MODELS Ms. HOOLEY. Thank you. Just one other question and that isI mean you talked about clearly there's some debate whether or not—what kind of impact, you know, which model should be used, what kind of impact there will be in the future but I think what I heard, at least from most of you, was there's some agreement that technology needs to be developed to address the issue. What do we need to do to develop that technology for the future to deal with global warming? Any one of you. Dr. Prinn, do you want to start or Dr. Robock?
Mr. ROBOCK. I'm not an expert on technology. I don't know how to build a more efficient car or refrigerator but one of the things we have to understand better is the precise patterns of climate change that will result. Right now, we have a pretty good handle on the global average but specifically where and what time of year the climate change will be, what time of day it will be, is something that still requires some work. So, we need a lot of intensive work on building better and more detailed models to understand exactly how it's going to impact the ski industry, how it's going to impact ocean transportation because different impacts require different responses. Is it is sea-level rise or increased fogs or storminess which might affect ocean ships going to change? Is precipitation or temperature going to change, which impacts agriculture? We need to understand that better and then we can develop responses.
Technology, we need in two regimes. One for adaptation. How can we live in a warmer world, which is going to happen anyway? And the other technology is how can we use energy and do what we want to do by producing less greenhouse gases. So, there's two types of technology that have to be developed.
Ms. HOOLEY. Dr. Prinn?
Mr. PRINN. Yes, certainly when I was speaking of technological developments, I was focusing on the issue of generating energy with much lower greenhouse gas emissions and there's been so little research in the last 20 years since the original 1970's program within the Department of Energy. So little effort, that, you know, things have sort of—a lot of interesting technologies have just laid benign. And there may be, of course, new inventions even. But you're clearly, you know, answering the question, “Can we use fossil fuels without emitting large amounts of CO2 into the atmosphere?” That's a very important question.
So much of the world's energy is going to come from fossil fuel, no matter what. And there are interesting ideas around, as many of you know, about the notion of going to a more hydrogen-burning economy where the hydrogen comes from the fossil fuel with known technology and the carbon dioxide is sequestered and there are ways of sequestering it that ought to be looked at very carefully. But, to me, that—when I was referring to technology, it was looking at things like that and, of course, renewables and nuclear. Put them all out and expand the options and expand the mix of ways of reducing energy.
I'd also agree with Alan Robock that technologies that focus on adaptation are also important. And I'd also echo what I think Ari Patrinos and Alan Robock have said, that if we improve our capability to predict climate, then adaptation becomes, in fact, a, you know, a very—a relatively easy thing to do compared to if we have no idea whether it's going to be warmer, colder, sea-level-this module sea-level, that module. Thank you.
Ms. HOOLEY. Thank you. Mr. Chairman, I would also ask unanimous consent to have my opening statement put in the record.
Chairman CALVERT. Without objection, so ordered. [The prepared statement of Ms. Hooley follows:)
Hearing on Countdown to Kyoto
October 7, 1997
I thank the Chairman for holding this very important hearing today, and I thank our distinguished witnesses Doctors Patrinos, Prinn, Robock and Spencer for joining us today to discuss what many of us consider an important role of our committee: to carefully evaluate scientific evidence in preparation for the upcoming policy declarations about to be made at the Third Conference of Parties in Kyoto.
I have been following this issue closely and I have been trying to reconcile the seemingly contradictory scientific reports that I have read about global warming. I agree that some trends such as escalating surface temperatures and heightened mountain glacier meltback indicate that global warming exists and that it could have profound effects on agriculture, forests, fish and even human health. However, I am also aware of the Microwave Satellite Unit records and other scientific indicators which present a different picture of many of the aspects of global warming.
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I appreciate having the opportunity to further examine the science which will shape our global warming policy. Our witnesses today are highly respected scientists who have conducted extensive research on this subject and will no doubt be able to shed some light on the topic of climate change.
Again, I thank the chairman and I look forward to hearing from our witnesses.