Climate Modeling

With respect to climate modeling, the Administration's FY2000 Information Technology for the Twenty-first Century Initiative will greatly improve U.S. climate modeling capabilities and management. The climate research community played an important role in shaping the initiative, and it will continue to contribute to its implementation over the next few years. One of the key problems identified by the NRC was lack of access to the world's most powerful supercomputers. The Information Technology Initiative will result in the creation and deployment of a new generation of U.S. supercomputers that will be made available to the U.S. academic community for a number of applications, including climate modeling. The development and operation of high end General Circulation Models is an extremely computerintensive application. The climate modeling community is clearly at the forefront of the research disciplines that require and are ready to make use of new computing capabilities.

I want to emphasize, however, that improvements in computing power, while necessary, are not sufficient for the U.S. to once again be among the world leaders in high end climate modeling. We also need to enhance the collaborations between existing modeling centers and the academic community, and take full advantage of their efforts in the creation of the new capabilities envisioned in the Information Technology Initiative. The NRC report was critical of the organization of U.S. climate modeling efforts, but it argued for both maintenance of the U.S. distributed system and a degree of further centralization. The report argues that the research program needs new capabilities, but within a national effort that is well-integrated.

One of the critical elements of defining the climate research plans for the USGCRP is the agreement on a revised strategy for climate modeling. DOE, NSF, NOAA, and NASA are working together with our office and OMB, through the National Science and Technology Council (NSTC), to assure a new level of integration and collaboration in USGCRP modeling efforts to enable us to get the most out of the new software and hardware that will result from the Information Technology Initiative. We must ensure that our plans integrate new capability into a new national effort that takes full advantage of the strengths of our academic and Federal Lab research community and that addresses important educational goals as well as technical objectives.

The U.S., and the other nations of the world, stand to gain considerably from this effort. Improving the U.S. climate modeling capability, and contributing this improvement to the assessment work of the IPCC, will help provide the world with more accurate information about what is likely to happen as a consequence of various levels of emissions and other human activity. More importantly, such an improved capability will also ensure that the U.S. has the means to perform U.S.-specific modeling investigations. This capability cannot be guaranteed by relying on the work done by other nations. Ensuring that we can meet our national needs is the primary justification for the proposed increased expenditures in this area.

Climate Observations

Regarding climate observations, we also have a report from the NRC that warns of gradual degradation of U.S. capabilities. It is important to place this in the proper context. Since the beginning of the USGCRP in the late 1980's, observations have been a major focus. Throughout the lifetime of the program, a major effort has been underway to develop new, more comprehensive, increasingly accurate measurement systems, driven by a consensus on the need for improved observational capability to address the broad suite of global environmental changes.

Over the past several years, many in the national and international climate science community have pointed to the fact that this long-term effort to develop broad new capabilities has not prevented some serious problems. The existing operational observing systems upon which climate science has relied for long-term systemic data are designed mainly to meet weather (short-term) rather than climate (long-term) requirements. Design changes, and, in some cases, gradual degradation of these systems are further hampering their ability to support climate research. For the most part, such systems are funded and managed completely outside the context of the USGCRP. For instance, neither the National Weather Service, nor NOAA's weather satellite programs are part of the USGCRP. So while we are developing important new capabilities, our ability to continue collecting some of the most important existing long-term climate data sets is not assured. It is simply a matter of different agencies with programs having different missions.

This widely recognized problem led the USGCRP to commission the “Adequacy of Climate Observing Systems" report from the NRC's Climate Research Committee. The report recommended that agencies should work through the USGCRP process and at higher government levels on a number of important actions, including stabilizing the existing operational capability and building climate observing requirements into the operational programs as a high priority.

As in the case of the NRC modeling report, the recommendations are proving helpful in the continuing development of USGCRP observational capabilities. Improving the U.S. climate observations capability has been and remains an important Administration priority. In addition to continued strong support for the development new observational capabilities, our FY2000 budget proposals have made a start at addressing the problems described in the NRC report.

The FY2000 budget proposals including augmenting NOAA's in situ observing networks (including the cooperative observer network, rain gauges, and ocean buoys), and data management activities to assure that data are available and accessible to the scientific community and other users. The USGCRP is also taking steps to improve collaboration between research satellite and in situ measurement programs (where new techniques are developed and tested) and operational satellite and in situ programs (which provide assured sources of data over the longterm).

The USGCRP program today is on the threshold of a major transition. Over the next several years, in addition to continuing to improve our understanding of the Earth's environment and how

it is changing, the USGCRP will greatly advance our knowledge about the implications of such change for society. The research successes of the last decade have laid the foundation for a global environmental change information service that will allow global change research results to be applied more effectively to national needs, including the long-term challenge of confronting climate change.

Perhaps the most difficult aspect of the climate challenge is the fact that it has developed gradually and steadily over time, rather than as a dramatic, sudden overnight change that demands our attention. The solution will also have to be long-term. The Administration believes that a careful, prudent strategy to address climate change must include scientific research and development to reduce remaining uncertainties and improve our understanding of impacts and adaptation potential. It must also include a strong research and development effort focused on the advanced clean and efficient energy technologies that hold significant promise for mitigating future emissions growth, avoiding future climate change, and providing economic and environmental benefits to our nation and the world.

Conclusion

The Administration's climate change actions and proposals are based on a combination of sound science and common sense. I want to conclude my remarks by summarizing what we have learned from research on global change that I believe provide a sound scientific base for actions.

Atmospheric concentrations of CO2 have increased about 30% since the onset of the Industrial Revolution. The level of CO2 in our atmosphere, which is about 365 parts per million by volume (ppmv) right now, is already significantly higher than it has been in 160,000 years -- and new analyses soon to be published will argue that it is higher than it has been in the last 400,000 years.

The IPCC Second Assessment Report, published in early 1996, reviewed all the scientific evidence and has identified a series of climate changes that have been observed during this period:

• Over the last century, the global mean (average) surface temperature increased by about 0.5 - 1° F.

• Over the same period, global mean sea level has already risen 4 to 10 inches, and further rise is inevitable.

⚫ Mountain glaciers have retreated worldwide this century.

• The average surface temperature this century is as warm or warmer than any century since at least 1400 AD.

As I noted earlier, the IPCC also concluded that "The balance of evidence suggests that there is a discernible human influence on global climate."

The IPCC cautions that, if we continue a “business as usual” emissions trajectory, atmospheric concentrations CO2 will exceed 700 ppm by the end of the next century. This would be a higher

change, the IPCC projects that this emissions trajectory would produce a number of adverse consequences, including the following:

• The Earth's average surface temperature is projected to increase by about 1 to 3.5° C (about 2 to 6.5° F) by 2100, a rate of warming that would probably be greater than during any comparable time interval during the last 10,000 years.

Sea level is projected to rise by 15-95 cm (6-38 inches) by 2100. Even after a hypothetical stabilization of greenhouse gas concentrations sea level would continue to rise for centuries.

An increase in the rate of evaporation as the climate warms, leading to 1) an increase in average global precipitation as well as frequency of intense rainfall and floods in some regions, and 2) to a decrease in soil moisture in some regions, leading to increased frequency and intensity of droughts.

When the IPCC Second Assessment Report was written, 1995 was the warmest year on record. In subsequent years, 1995 was surpassed by 1997, and 1997 was in turn surpassed by 1998. The long-term surface temperature data records of NOAA, the United Kingdom Meteorological Office, and the NASA Goddard Institute of Space Studies all show this to be the case. In fact, newly published findings on the long-term climate of North America, based on analysis of tree rings, ice cores, coral reefs, and sediments, indicate that 1998 was probably the warmest year in the last 1000 years. While this was in part due to a strong El Niño, its contribution was an addition to a clear warming trend.

Indeed, the strong El Niño event that disrupted our climate conditions and those in many other nations provided us with an unpleasant preview of the types of impacts we can expect in a warmer and wetter world that unmitigated climate change would produce, including more intense rainfalls and a simultaneous increase in both floods and droughts. Fortunately, improved predictive capability, developed through the USGCRP helped many nations minimize the economic disruption of one bad year. But imagine if these conditions were typical rather than unusual.

I believe, as do most scientists who have carefully studied this problem, that we need to confront this growing challenge now. The evidence is compelling that emissions of greenhouse gases from human activities are amplifying the Earth's natural greenhouse effect and warming the planet's surface. Computer models suggest that such warming is likely to lead to further climate disruptions and ecological impacts as sea levels rise, patterns of precipitation change, atmospheric and ocean currents shift, and plants and animals migrate.

So, the question facing us is - what specific constructive steps do we take? First, it requires a sustained and enhanced commitment to energy research, development and deployment. It is critical that we begin our long-term efforts in this area sooner rather than later, because the consequences of our near-term technology choices are themselves significant and long-lasting. The longer we continue on a “business as usual” path, the greater the degree of warming, the faster the rate of climate change, and the more severe the negative effects for human and

ecological systems. Second, it requires continued research into the science of climate change to help guide our understanding of impacts and mitigation and adaptation options.

Mr. Chairman, doing nothing is the high risk option. What is at stake is the health and well-being of our children and future generations, as well as our environmental quality and global stability. The same scientific and technical capabilities that have helped identify this problem can help us overcome it. We have in hand the means to choose a new path of robust economic growth that also helps reduce the climate change threat. The Administration's climate change science and energy technology proposals are important initial steps in this regard.

Thank you, Mr. Chairman, and members of the committee, for your attention today. I would be happy now to answer your questions.