The Potential to Reduce Uncertainty in Regional Runoff Projections from Climate Models

TitleThe Potential to Reduce Uncertainty in Regional Runoff Projections from Climate Models
Publication TypeJournal Article
Year of Publication2019
JournalNature Climate Change
Volume9
Number12
Pages926-933
Abstract / Summary

Increasingly, climate change impact assessments rely directly on climate models. Assessments of future water security depend in part on how the land model components in climate models partition precipitation into evapotranspiration and runoff, and on the sensitivity of this partitioning to climate. Runoff sensitivities are not well constrained, with CMIP5 models displaying a large spread for the present day, which projects onto change under warming, creating uncertainty. Here we show that constraining CMIP5 model runoff sensitivities with observed estimates could reduce uncertainty in runoff projection over the western United States by up to 50%. We urge caution in the direct use of climate model runoff for applications and encourage model development to use regional-scale hydrological sensitivity metrics to improve projections for water security assessments.

URLhttp://dx.doi.org/10.1038/s41558-019-0639-x
DOI10.1038/s41558-019-0639-x
Journal: Nature Climate Change
Year of Publication: 2019
Volume: 9
Number: 12
Pages: 926-933
Publication Date: 12/2019

Increasingly, climate change impact assessments rely directly on climate models. Assessments of future water security depend in part on how the land model components in climate models partition precipitation into evapotranspiration and runoff, and on the sensitivity of this partitioning to climate. Runoff sensitivities are not well constrained, with CMIP5 models displaying a large spread for the present day, which projects onto change under warming, creating uncertainty. Here we show that constraining CMIP5 model runoff sensitivities with observed estimates could reduce uncertainty in runoff projection over the western United States by up to 50%. We urge caution in the direct use of climate model runoff for applications and encourage model development to use regional-scale hydrological sensitivity metrics to improve projections for water security assessments.

DOI: 10.1038/s41558-019-0639-x
Citation:
Lehner, F, A Wood, J Vano, D Lawrence, M Clark, and J Mankin.  2019.  "The Potential to Reduce Uncertainty in Regional Runoff Projections from Climate Models."  Nature Climate Change 9(12): 926-933.  https://doi.org/10.1038/s41558-019-0639-x.