This technical input report on climate and energy-water-land (EWL) system interactions has been prepared for the U.S. Department of Energy in support of the U.S. National Climate Assessment (NCA). Prepared on an accelerated schedule to fit the NCA’s timeline, it provides a summary of existing information and understanding of this broad topic.

This report provides a framework to characterize and understand the important elements of climate and EWL system interactions. It identifies many of the important issues, discusses our understanding of those issues, and identifies the research needs to address the priority scientific challenges and gaps in our understanding. Much of the discussion is organized around two discrete case studies with the broad themes of (1) extreme events and (2) regional differences. These case studies help demonstrate unique ways in which energy-water-land interactions can occur and be influenced by climate. In addition, a series of “illustrations” portray representative decision-making considerations relevant to climate-EWL interfaces. Key findings from the report are summarized below, according to the report section in which they are found.