Estimating future global per capita water availability based on changes in climate and population

Journal Article · Sun Jan 01 04:00:00 EST 2012 · Computers & Geosciences

DOI:https://doi.org/10.1016/j.cageo.2012.01.019· OSTI ID:1038472

Parish, Esther S ^[1]; Kodra, Evan ^[2]; Ganguly, Auroop R ^[2]; Steinhaeuser, Karsten ^[3]

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1. ORNL
2. Northeastern University
3. University of Minnesota

Human populations are profoundly affected by water stress, or the lack of sufficient per capita available freshwater. Water stress can result from overuse of available freshwater resources or from a reduction in the amount of available water due to decreases in rainfall and stored water supplies. Analyzing the interrelationship between human populations and water availability is complicated by the uncertainties associated with climate change projections and population projections. We present a simple methodology developed to integrate disparate climate and population data sources and develop first-order per capita water availability projections at the global scale. Simulations from the coupled land-ocean-atmosphere Community Climate System Model version 3 (CCSM3) forced with a range of hypothetical greenhouse gas emissions scenarios are used to project grid-based changes in precipitation minus evapotranspiration as proxies for changes in runoff, or fresh water supply. Population growth changes according to several Intergovernmental Panel on Climate Change (IPCC) storylines are used as proxies for changes in fresh water demand by 2025, 2050 and 2100. These freshwater supply and demand projections are then combined to yield estimates of per capita water availability aggregated by watershed and political unit. Results suggest that important insights might be extracted from the use of the process developed here, notably including the identification of the globe s most vulnerable regions in need of more detailed analysis and the relative importance of population growth versus climate change in in altering future freshwater supplies. However, these are only exemplary insights and, as such, could be considered hypotheses that should be rigorously tested with multiple climate models, multiple observational climate datasets, and more comprehensive population change storylines.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1038472
• Journal Information: Computers & Geosciences, Journal Name: Computers & Geosciences Vol. 42; ISSN 0098-3004; ISSN CGEODT
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AVAILABILITY
CLIMATE MODELS
CLIMATES
CLIMATIC CHANGE
FRESH WATER
GREENHOUSE GASES
HUMAN POPULATIONS
PRECIPITATION
RUNOFF
SUPPLY AND DEMAND
WATER
WATERSHEDS
climate change impacts
population growth
resource scarcity
water availability