Influence of internal variability on population exposure to hydroclimatic changes

Datos Bibliográficos

ID15549201
AutoresJustin S Mankin (0000-0003-2520-4555, Columbia University, autor de correspondencia), Daniel Viviroli (0000-0002-1214-8657, University of Zurich), Mesfin M Mekonnen (0000-0002-3573-9759, University of Twente), Arjen Y Hoekstra (0000-0002-4769-5239, National University of Singapore), Radley M Horton (0000-0002-5574-9962, Columbia University), Jason E Smerdon (0000-0001-6276-0249, Lamont-Doherty Earth Observatory), Noah S Diffenbaugh (0000-0002-8856-4964, National University of Singapore)
Año2017
Volumen12
Número4
Páginas044007-044007
Fecha de publicación2017-02-07
Peer ReviewedSí
Open AccessSí
TipoARTICLE
RevistaEnvironmental Research Letters (JOURNAL)
Identificadores de la revistaISSN: 1748-9326 • E-ISSN: 1748-9326
EditorialIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/aa5efc
OpenAlexW2587097626
IdiomaEN
Citas recibidas3
Referencias citadas53

Future freshwater supply, human water demand, and people's exposure to water stress are subject to multiple sources of uncertainty, including unknown future pathways of fossil fuel and water consumption, and 'irreducible' uncertainty arising from internal climate system variability. Such internal variability can conceal forced hydroclimatic changes on multi-decadal timescales and near-continental spatial-scales. Using three projections of population growth, a large ensemble from a single Earth system model, and assuming stationary per capita water consumption, we quantify the likelihoods of future population exposure to increased hydroclimatic deficits, which we define as the average duration and magnitude by which evapotranspiration exceeds precipitation in a basin. We calculate that by 2060, backsim31%–35% of the global population will be exposed to >50% probability of hydroclimatic deficit increases that exceed existing hydrological storage, with up to 9% of people exposed to >90% probability. However, internal variability, which is an irreducible uncertainty in climate model predictions that is under-sampled in water resource projections, creates substantial uncertainty in predicted exposure: backsim86%–91% of people will reside where irreducible uncertainty spans the potential for both increases and decreases in sub-annual water deficits. In one population scenario, changes in exposure to large hydroclimate deficits vary from −3% to +6% of global population, a range arising entirely from internal variability. The uncertainty in risk arising from irreducible uncertainty in the precise pattern of hydroclimatic change, which is typically conflated with other uncertainties in projections, is critical for climate risk management that seeks to optimize adaptations that are robust to the full set of potential real-world outcomes

Climate change · Climate model · Climatology · Downscaling · Evapotranspiration · Geography · Meteorology · Population · Population model · Precipitation · Range (aeronautics · Climate variability and models · Environmental Science · Hydrology and Watershed Management Studies · Water resources management and optimization · Demography · Ecology · Geology