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NSF & Congress

Hearing Summary: Countdown to Kyoto, Part 1: The Science of a Global Climate Change Agreement

October 7, 1997

The witnesses described the current status of knowledge regarding Global Climate Change. Witnesses were cautious about the extent of future warming and the possibility that human activity is having an impact on global warming.

All agreed that today's projections of climate were uncertain and this uncertainty was due primarily to the current limited state of climate modeling. According to Dr. Spencer of NASA, "the physics contained in current general circulation models (GCM's -- used to predict future fluctuations in climate) are still insufficient to have much confidence in their predicted magnitude of global warming." According to Dr. Prinn of MIT, also noted that there may be fundamental limitations to our ability to predict climate due to chaotic processes such as we already see in weather prediction.

Dr. Patrinos of DoE, noted the recent improvement of the GCM's and noted also the findings of a Forum on Global Change Modeling -- convened by OSTP and GAO -- that were in general agreement with the findings of the 1995 IPCC report. However, Patrinos acknowledged that "there are still significant uncertainties in GCM predictions". He said that investments by DoE, NSF and other agencies like NOAA and NASA are "improving our ability to predict global climate. So far, Patrinos said, there have been promising new developments, including the development of the Parallel Climate Model (PCM) by a team at NCAR led by Dr. Warren Washington.

Noting that the science of global climate change is less than certain, many members voiced concern over the Clinton Administration's negotiations at the Kyoto conference on global climate change. According to subcommittee Chairman Ken Calvert (R-CA), "[i]t was made clear from testimony today that, although scientists agree on the warming effect of "greenhouse gasses", there are a wide variety of views on how such basic climate influences such as clouds, water vapor, and even the sun affect the process", Calvert said in a prepared statement.

Much discussion occurred over more recent climate projections and that show the rate of global warming in the future to be much less than originally predicted only a few years ago. Rep. Dana Rohrabacher (R-CA) derided predictions of rapid global warming as "ridiculous", saying that no one can predict the what the weather will be 10 days from now, much less many years from now. Full Committee Chairman James Sensenbrenner (R-WI) also noted the recent "cooler" climate projections and also criticized the climate science establishment for not providing timely, useful information about global climate change that could be translated into policy. Sensenbrenner asked rhetorically how Members of Congress could ask their constituents to make significant sacrifices in energy and transportation use for the purpose of reducing greenhouse gasses when the science behind global climate change is anything close to definitive.

Even though the science of global climate change was less than certain, Dr. Prinn said that it would be foolish to take no action now. "Scientists cannot presently rule out rapid warming forecasts" Dr. Prinn said, it would be irresponsible to ignore such as risk." Prinn did not call for drastic measures however, noting that reducing emissions through efficiency would not reduce predicted global temperature increases by too much. Noting that fossil fuel will likely remain the primary source of the world's energy, Prinn argued that the U.S. should invest much more heavily in energy technology that could reduce carbon emissions from fossil fuel use. He also said that use alternative energy sources must be expanded including expansion of nuclear energy use.

Rep. Mike Doyle (D-PA) agreed with this assessment saying that any solution to greenhouse gas emissions must go beyond regulation: "I urge the Administration to look at emissions reduction as a challenge to our scientific and technological know-how, not as an opportunity to burden major segments of our economy", Doyle said.

There was some discussion over the future of global change research especially the need for continued investment in climate modeling research. Members -- including Subcomittee Chair Calvert -- voiced support for continued research and witnesses noted that limitations in climate models were due to limited research funds, among other factors. Insufficient computing power was also cited by Dr. Spencer and Dr. Robock as an obstacle to creating more accurate climate models.