system, reducing the likelihood of unanticipated changes and improving climate models in the long term.
Uncertainty is a significant aspect of climate modeling and needs to be properly addressed by the climate modeling community. To facilitate this, the United States should more vigorously support research on uncertainty, including understanding and quantifying climate projection uncertainty, automating approaches to optimization of uncertain parameters within models, communicating uncertainty to both users of climate model output and decision makers, and developing deeper understanding on the relationship between uncertainty and decision making.
Climate models are among the most sophisticated simulation tools developed by mankind and the “what-if” questions we are asking of them involve a mind-boggling number of connected systems. As the scope of climate models has expanded, so has the need to validate and improve them. Enormous progress has been made in the past several decades in improving the utility and robustness of climate models, but more is needed to meet the desires of decision makers who are increasingly relying on the information from climate models.
The committee believes that the best path forward is a strategy centered around the integration of the decentralized U.S. climate modeling enterprise—across modeling efforts, across a hierarchy of model types, across modeling communities focused on different space and time scales, and between model developers and model output users. A diversity of approaches is necessary for progress in many areas of climate modeling and is vital for addressing the breadth of users’ needs. If adopted, this strategy of increased unification amidst diversity will allow the United States to more effectively meet the climate information needs of the nation in the coming decades and beyond.