Integrating federal research on global change and climate change

Climate models encapsulate scientists' best understanding of climate and related Earth system processes and are important tools for understanding past, present, and future climate change.  Most modern climate models also include representations of the oceans, atmosphere, cryosphere, and land surface, and their interactions.  Some Earth system models also simulate a range of biophysical processes that involve terrestrial and marine ecosystems and human activities.

Climate and Earth system models are computer-based numerical techniques to solve mathematical equations, yielding a projected evolution of the climate system. Rather than trying to predict the exact future state of the weather, climate models predict changes in the frequency and characteristics of weather phenomena (such as droughts and hurricanes) and average seasonal weather patterns.

In order to take on the challenge of projecting impacts and vulnerability caused by climate change, we must strengthen our ability to predict climate at regional and local scales and at the decadal time scale.  This information serves as the starting point for policymaking, planning, and decision support models, as well as impacts, adaptation, and vulnerability studies of energy, the environment, and economic security. The results can also inform significant U.S. infrastructure decisions and investments.

Understanding the consequences of climate change, with particular attention to options for mitigation and adaptation at regional and local scales, requires that next-generation models dramatically improve their depiction of local precipitation patterns, extreme events in temperature, and wind; reduce uncertainties regarding key elements affecting climate such as aerosols and carbon fluxes; and capitalize on leadership-class computers and related cyberinfrastructure.

Finally, a new generation of Integrated Assessment Models (IAMs) is required that combines both the drivers and consequences of climate change within common modeling frameworks.  At the center of IAMs are representatives of present and projected future human activities and their potential influence on the climate system. IAMs address the two-way coupling between changes in the natural climate system and human activities, including those undertaken to mitigate climate change, to adapt to climate change, or as consequences of changes in climate or other aspects of the Earth system.