Department of Defense (DoD) installations face a myriad of different climate risks across the contiguous United States (CONUS) and Alaska and Hawaii (outside CONUS, or OCONUS) such as increased intensity of precipitation events and sustained increases in high and low temperatures. These risks from a changing climate are assessed using outputs from Global Climate Models, which are downscaled using a plethora of downscaling methods, resulting in a potentially paralyzing amount of data. What is lacked now are meaningful, objective tests and integrated interpretations to discriminate between methods to answer, “Which methods are fit for purpose?”. Without answering that question using a formal and scientifically credible evaluation of the fitness of downscaling methods, risk managers at DoD installations can have an incomplete or mischaracterized portrayal of the climate threats, limiting the effectiveness of their adaptation actions. The primary goal of this project is to prevent that mischaracterization and to enable DoD to make better informed decisions on strategic adaptation planning in the face of uncertain climate change impacts through development of a decision support tool that summarizes the design objectives, performance, and relevance of a range of downscaling methods.

The main science outcome is a fundamentally improved understanding of downscaled climate information for DoD installations, made accessible through a prototype decision support tool. It is based on a comprehensive characterization and evaluation of downscaled climate information for approximately five DoD installations across CONUS and OCONUS. A core component of the tool is a series of tests for evaluating the relevance, performance and distinguishability of downscaling methods with a generalizable workflow. The decision support tool will blend a catalogue of method characteristics, the performance evaluation data, and user input information. The final design and operational outputs of the tool will be developed with iterative review and comments from an advisory group that will convene and consult over the project’s lifetime. This group, representing DoD installation managers and others with experience using downscaled outputs for risk assessments, will help create the guidance document, tool-specific user's guide, and web-based education and training tutorials. Incorporating the unprecedentedly large range of downscaling methods will result in a first of its kind set of documents, training material, and software for understanding and using downscaling methods that are best fit for the purposes they can be applied for.

This project will produce, test, and package new science along with specific interpretations to inform explicit choices made when using climate change information in current and future DoD assessments of climate risks and impacts. This project will provide crucial support for DoD and its military Departments to respond successfully to recent Congressional and internal directives concerning climate change. The decision support tool will be a modular, extensible design, so that it can continue to include the most recent climate science advances as data and methods continue to improve. This combination of an extensible suite of tests and interpretations made with a dedicated applications tool will enable current and future users to synthesize guidance recommendations using the latest downscaled products and a performance baseline composed of the fully evaluated metrics. (Anticipated Project Completion - 2026)