Finding 8.7: One cost associated with the effort and time pressure of participating in the CMIP/IPCC is the reduction of time and computational resources that model developers have to devote to fundamental research that produces results on longer time scales.
THE WAY FORWARD
For decades, the United States has sustained the largest climate research enterprise in the world. The first climate simulation model was developed in the United States, and the United States continues to support a diverse range of approaches to better understanding future extreme weather and climate on all space and time scales. A robust international climate modeling community has evolved, including state-of-theart efforts in Europe in regional and global modeling, as well as growing efforts in Asia supported by large new investments in computing. This has led to Earth system models that simulate the current climate more accurately and comprehensively than in the past, and the application of these and finer-scale, more specialized regional models to many societal and scientific problems, although model-related uncertainties in future climate projections remain substantial. In response to IPCC-type assessments, the international community, led by the United States, has pioneered mechanisms for distributing an ever-growing set of standardized outputs from international suites of models. These are a major resource for the U.S. climate community.
On balance the CMIP activities are a clear positive for U.S. climate modeling activities. These activities help to keep U.S. models and model-based research at the leading edge of activity around the world. However, the costs associated with these activities imply a need for balance among the various sorts of activities in modeling centers to achieve some optimal outcome, especially in light of the rapidly growing scope of CMIP experiments. These activities are important enough to be considered an expected part of the model development process and thus warrant sustained support. This includes support for participation in the CMIP/IPCC activities and for the systems to archive model output in a way that is freely and easily available to users. Such support would include (a) software specialists for the development and maintenance of data storage and distribution systems that meet the needs of the climate community and (b) the required hardware, including storage, transmission, and analysis capabilities. This support would likely include resources at the modeling centers that run the climate model simulations, as well as support for a centralized capability that coordinates this activity within the United States.