EPA Research Partner Support Story: Population and land use projections

Partner: California Energy Commission
Challenge: Population and land use projections to the year 2100 consistent with emissions storylines
Resource: Integrated Climate and Land Use Scenarios (ICLUS) version 2
Project Period: 2012 – 2019

EPA ORD researchers developed national population, land use and impervious surface projections that the state of California used in its Third Climate Change Assessment. For the fourth assessment, the state used EPA’s updated climate model, the Integrated Climate and Land Use Scenarios version 2 (ICLUS v2), as a basis for land use scenarios in California, with minor modifications as necessary. These scenarios were used across multi-disciplinary and multi- sectoral research that informs the Fourth Assessment.

“It is extraordinarily beneficial to climate planning in California to be able to rely on tools like ICLUS v2 to provide a federally-vetted baseline for coordinated climate assessment research.” – California Natural Resources Agency, former Special Assistant for Climate Change JR De la Rosa

ICLUS v2 uses the latest census, land use and land cover datasets to model population growth, residential housing changes, and commercial and industrial development nationally to the year 2100. Projections use information on fertility, mortality and international immigration rates that are consistent with global storylines (e.g., Shared Socioeconomic Pathways) used in climate change impacts, vulnerability and adaptation assessments. In addition, ICLUS v2 projections use information on domestic migration, including how future climate may make certain places more desirable. Combined with the addition of commercial and industrial land uses, the updated projections from ICLUS v2 helped the state of California better assess potential future impacts from climate change and prepare adaptation and mitigation responses.