In addition, it is anticipated that over the coming decades climate change assessments will be conducted in the United States that focus on both national and regional scales, with an increasing emphasis on adaptation. The utility of such assessments is greatly enhanced through the active use of climate models both from the United States and from institutions around the world. The utility of a large number of models enhances the credibility of any such assessments by providing the potential for an improved assessment of the uncertainty of climate change projections. The U.S. participation in CMIP and related activities greatly facilitates the use of multimodel ensembles incorporating U.S. and international models.
U.S. modeling centers should be encouraged to participate in international activities, including the execution of internationally coordinated numerical experiments such as CMIP, and to make that data publicly available. In addition, there should be sustained support and encouragement for the participation of U.S. scientists in international activities in support of climate modeling and the use of climate models, such as those organized by WCRP, and for the systems to archive model output from leading U.S. climate models, and to make that output freely and easily accessible (this is discussed in Chapter 10).
Recommendation 8.1: To advance in the next 10-20 years, U.S. climate modeling efforts should continue to strive for a suitable balance among and support for
• the application of current generation models to support climate research activities, as well as national and international projects such as CMIP/IPCC;
• near-term development activities that lead to incremental but meaningful improvements in models and their predictions; and
• the investment of resources to conduct and capitalize on long-lead-time research that offers the potential for more fundamental and transformational advances in climate modeling.
Recommendation 8.2: The United States should continue to support the participation of U.S. scientists and institutions in international activities, such as model intercomparisons, including support for systems to archive model output, because such activities have proven effective in robustly addressing user needs for climate information and for advancing U.S. climate models.
Recommendation 8.3: To enhance their robustness, national and regional climate change/adaptation assessments should incorporate projections from leading international climate models as well as those developed in the United States.