Less Reliable Water Availability in the 21st Century Projected Climate

TitleLess Reliable Water Availability in the 21st Century Projected Climate
Publication TypeJournal Article
Year of Publication2013
JournalEarth's Future
Volume2
Number3
Pages152–160
Date Published03/2013
Abstract / Summary

The temporal variability of river and soil water affects society at time scales ranging from hourly to decadal. The available water (AW), i.e., precipitation minus evapotranspiration, represents the total water available for runoff, soil water storage change, and ground water recharge. The reliability of AW is defined as the annual range of AW between local wet and dry seasons. A smaller annual range represents greater reliability and a larger range denotes less reliability. Here we assess the reliability of AW in the 21st century climate projections by 20 climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). The multimodel consensus suggests less reliable AW in the 21st century than in the 20th century with generally decreasing AW in local dry seasons and increasing AW in local wet seasons. In addition to the canonical perspective from climate models that wet regions will get wetter, this study suggests greater dryness during dry seasons even in regions where the mean climate becomes wetter. Lower emission scenarios show significant advantages in terms of minimizing impacts on AW but do not eliminate these impacts altogether.

DOI10.1002/2013EF00015
Journal: Earth's Future
Year of Publication: 2013
Volume: 2
Number: 3
Pages: 152–160
Date Published: 03/2013

The temporal variability of river and soil water affects society at time scales ranging from hourly to decadal. The available water (AW), i.e., precipitation minus evapotranspiration, represents the total water available for runoff, soil water storage change, and ground water recharge. The reliability of AW is defined as the annual range of AW between local wet and dry seasons. A smaller annual range represents greater reliability and a larger range denotes less reliability. Here we assess the reliability of AW in the 21st century climate projections by 20 climate models from phase 5 of the Coupled Model Intercomparison Project (CMIP5). The multimodel consensus suggests less reliable AW in the 21st century than in the 20th century with generally decreasing AW in local dry seasons and increasing AW in local wet seasons. In addition to the canonical perspective from climate models that wet regions will get wetter, this study suggests greater dryness during dry seasons even in regions where the mean climate becomes wetter. Lower emission scenarios show significant advantages in terms of minimizing impacts on AW but do not eliminate these impacts altogether.

DOI: 10.1002/2013EF00015
Citation:
Kumar, S, DM Lawrence, PA Dirmeyer, and J Sheffield.  2013.  "Less Reliable Water Availability in the 21st Century Projected Climate."  Earth's Future 2(3): 152–160.  https://doi.org/10.1002/2013EF00015.