Downscaled CMIP3 and CMIP5 Climate and Hydrology Projections
Important Notice for Using Climate Projections
Climate projections can be useful for making decisions about the future, but the limitations of climate models make it easy to misinterpret or misuse their results. Be aware that:
- Climate projections are not predictions. Projections are based on assumptions about future human emissions of greenhouse gases and other policy choices.
- Climate projections do not attempt to predict the timing of meteorological events such as storms, droughts, or El Niños. The location and timing of future extreme weather events cannot be deduced from climate model projections.
- Projections vary from model to model: the best projection dataset for one location and purpose may not be the best for other situations. Considering a range of projections may help you gain a more complete picture of potential future risks.
- The increased spatial resolution of statistically downscaled projections available for temperature and precipitation may not be available for all parameters. In addition, increased resolution does not necessarily equate to greater fidelity or reliability.
For decisions involving the use of climate model projections, you may want to consider seeking expertise.
This archive contains high-resolution translations of climate projections for the contiguous United States. Archive content is based on global climate projections from the World Climate Research Programme’s Coupled Model Intercomparison Projects. Phase 3 (CMIP3) and Phase 5 (CMIP5) of these experiments informed the Intergovernmental Panel on Climate Change’s Fourth Assessment Report and Fifth Assessment Report, respectively.
Users can specify a customized data retrieval through the Subset Request form, or access ftp directories containing projection-specific full coverage datasets (variable, space, time) in netcdf data format through the Complete Archives tab.
Downscaled projections available in the archive were developed using: (1) monthly bias-correction and spatial downscaling (BCSD); and (2) daily bias correction constructed analogs (BCCA).
The site also contains two sets of hydrologic projections: (1) CMIP5 projections based on the monthly BCSD climate projections for the contiguous U.S.; and (2) CMIP3 projections for the western United States.
Additionally, the archive offers climate model results that have been interpolated to a common, 1° x 1° horizontal grid (but not downscaled), and results that have been interpolated to the 1° x 1° grid and “bias corrected,” but not downscaled.