The Department of Defense (DoD) Climate Assessment Tool, or DCAT, was released department-wide in September 2020 by the Office of the Deputy Assistant Secretary of Defense, Environment and Energy Resilience (ODASD(E&ER)). The DCAT enables personnel at all levels of the department — from installation planners to leadership — to understand each location's exposure to climate-related hazards of interest to Congress using historical data and future climate projections. Under DoD Policy, the Assistant Secretary of Defense for Energy, Installations, and Environment, principally through the technology development capabilities of SERDP/ESTCP, shall update tools such as DCAT at such intervals as necessary for appropriate technology transfer, data currency, and system functionality.

In 2021, the Secretary of Defense committed to the POTUS that the Department would deliver the DCAT to all major installations, including international locations, and to deliver an analogous tool to six Partner Nations, in 2023. Both of these deliverables require the DCAT team within ODASD(E&ER) to evaluate the availability of higher-resolution, downscaled climate model and other data for international locations, as well as the effects on the analytical capability of the DCAT of shifting from best-available global data to best available regional data. This project addresses the evaluation of international data alternatives, taking into account new data that may become available from the recently completed Intergovernmental Panel on Climate Change Sixth Assessment Report Coupled Model Intercomparison Project (CMIP6) modeling effort or other authoritative data.

The DCAT international version treats international locations (those outside the Contiguous U.S. (CONUS), Alaska and Hawaii) as a single region to enable comparison of climate exposure across all international installations, just as the CONUS-AK-HI locations are treated as a single region. This comparability requires that the same or very comparable data are used at each installation to enable an “apples-to-apples” comparison. The consequence of this is that that best available data globally is far coarser in resolution, and potentially of greater uncertainty, than may be available for some regions (Europe, Far East, Australia) and locations. To support the 2023 deliverables, the DCAT ODASD(E&ER) team requires an analysis of the effects of (1) splitting international locations into subregions; (2) adding additional, subregion-specific datasets; and (3) expanding the tool into other regions of the world. To address these concerns, there are four tasks within this project:

Task 1. Identify and Evaluate Authoritative Global, Regional and National Data for Inclusion in the DCAT

Task 2. Data Selection

Task 3. Data Delivery

Task 4. Report Delivery

The DCAT takes the position that climate model uncertainty is best reduced by reliance on model ensembles rather than one or a handful of models that might improve representation of certain processes at certain locations but have poorer fidelity for other processes and areas. Consequently, with respect to climate model data, the interest in this scope is at the model ensemble level, not at the level of individual climate models.