A global assessment of the impact of climate change on water scarcity
TL;DR: In this article, the authors present a global scale assessment of the impact of climate change on water scarcity, using the Water Crowding Index (WCI) and the Water Stress Index to calculate exposure to increases and decreases in global water scarcity.
Abstract: This paper presents a global scale assessment of the impact of climate change on water scarcity. Patterns of climate change from 21 Global Climate Models (GCMs) under four SRES scenarios are applied to a global hydrological model to estimate water resources across 1339 watersheds. The Water Crowding Index (WCI) and the Water Stress Index (WSI) are used to calculate exposure to increases and decreases in global water scarcity due to climate change. 1.6 (WCI) and 2.4 (WSI) billion people are estimated to be currently living within watersheds exposed to water scarcity. Using the WCI, by 2050 under the A1B scenario, 0.5 to 3.1 billion people are exposed to an increase in water scarcity due to climate change (range across 21 GCMs). This represents a higher upper-estimate than previous assessments because scenarios are constructed from a wider range of GCMs. A substantial proportion of the uncertainty in the global-scale effect of climate change on water scarcity is due to uncertainty in the estimates for South Asia and East Asia. Sensitivity to the WCI and WSI thresholds that define water scarcity can be comparable to the sensitivity to climate change pattern. More of the world will see an increase in exposure to water scarcity than a decrease due to climate change but this is not consistent across all climate change patterns. Additionally, investigation of the effects of a set of prescribed global mean temperature change scenarios show rapid increases in water scarcity due to climate change across many regions of the globe, up to 2 °C, followed by stabilisation to 4 °C.
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01 Jan 2018
TL;DR: In this article, the authors present a survey of women's sportswriters in South Africa and Ivory Coast, including: Marco Bindi (Italy), Sally Brown (UK), Ines Camilloni (Argentina), Arona Diedhiou (Ivory Coast/Senegal), Riyanti Djalante (Japan/Indonesia), Kristie L. Ebi (USA), Francois Engelbrecht (South Africa), Joel Guiot (France), Yasuaki Hijioka (Japan), Shagun Mehrotra (USA/India), Ant
Abstract: Lead Authors: Marco Bindi (Italy), Sally Brown (UK), Ines Camilloni (Argentina), Arona Diedhiou (Ivory Coast/Senegal), Riyanti Djalante (Japan/Indonesia), Kristie L. Ebi (USA), Francois Engelbrecht (South Africa), Joel Guiot (France), Yasuaki Hijioka (Japan), Shagun Mehrotra (USA/India), Antony Payne (UK), Sonia I. Seneviratne (Switzerland), Adelle Thomas (Bahamas), Rachel Warren (UK), Guangsheng Zhou (China)
614 citations
TL;DR: This study provides a first assessment of continuous sub-national trajectories of blue water consumption, renewable freshwater availability, and water scarcity for the entire 20th century to suggest measures for alleviating water scarcity and increasing sustainability.
Abstract: Water scarcity is a rapidly growing concern around the globe, but little is known about how it has developed over time. This study provides a first assessment of continuous sub-national trajectories of blue water consumption, renewable freshwater availability, and water scarcity for the entire 20th century. Water scarcity is analysed using the fundamental concepts of shortage (impacts due to low availability per capita) and stress (impacts due to high consumption relative to availability) which indicate difficulties in satisfying the needs of a population and overuse of resources respectively. While water consumption increased fourfold within the study period, the population under water scarcity increased from 0.24 billion (14% of global population) in the 1900s to 3.8 billion (58%) in the 2000s. Nearly all sub-national trajectories show an increasing trend in water scarcity. The concept of scarcity trajectory archetypes and shapes is introduced to characterize the historical development of water scarcity and suggest measures for alleviating water scarcity and increasing sustainability. Linking the scarcity trajectories to other datasets may help further deepen understanding of how trajectories relate to historical and future drivers, and hence help tackle these evolving challenges.
524 citations
Cites background from "A global assessment of the impact o..."
...= ÷ stress per capita consumption shortage (6)...
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South University of Science and Technology of China1, Swiss Federal Institute of Aquatic Science and Technology2, University of Basel3, University of Nottingham4, Aalto University5, University of Kassel6, ETH Zurich7, National Institute for Environmental Studies8, Utrecht University9, Goddard Institute for Space Studies10, Columbia University11, Beijing Forestry University12, University of Tokyo13
TL;DR: A variety of indicators that have been developed to capture different characteristics of water scarcity are reviewed, finding challenges remain on appropriate incorporation of green water, water quality, environmental flow requirements, globalization and virtual water trade in water scarcity assessment.
Abstract: Water scarcity has become a major constraint to socio-economic development and a threat to livelihood in increasing parts of the world. Since the late 1980s, water
scarcity research has attracted much political and public attention. We here review a variety of indicators that have been developed to capture different characteristics of
water scarcity. Population, water availability and water use are the key elements of these indicators. Most of the progress made in the last few decades has been on the
quantification of water availability and use by applying spatially explicit models. However, challenges remain on appropriate incorporation of green water (soil moisture), water quality, environmental flow requirements, globalization and virtual water trade in water scarcity assessment. Meanwhile, inter- and intra- annual variability of water availability and use also calls for assessing the temporal dimension of water scarcity. It requires concerted efforts of hydrologists, economists, social scientists, and environmental scientists to develop integrated approaches to
capture the multi-faceted nature of water scarcity.
444 citations
TL;DR: In this paper, the authors present an assessment of the impacts of climate change on a series of indicators of hydrological regimes across the global domain, using a global hydrologogical model run with climate scenarios constructed using pattern-scaling from 21 CMIP3 (Coupled Model Intercomparison Project Phase 3) climate models.
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References
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01 Jan 2007
TL;DR: The first volume of the IPCC's Fourth Assessment Report as mentioned in this paper was published in 2007 and covers several topics including the extensive range of observations now available for the atmosphere and surface, changes in sea level, assesses the paleoclimatic perspective, climate change causes both natural and anthropogenic, and climate models for projections of global climate.
Abstract: This report is the first volume of the IPCC's Fourth Assessment Report. It covers several topics including the extensive range of observations now available for the atmosphere and surface, changes in sea level, assesses the paleoclimatic perspective, climate change causes both natural and anthropogenic, and climate models for projections of global climate.
32,826 citations
TL;DR: The fifth phase of the Coupled Model Intercomparison Project (CMIP5) will produce a state-of-the- art multimodel dataset designed to advance the authors' knowledge of climate variability and climate change.
Abstract: The fifth phase of the Coupled Model Intercomparison Project (CMIP5) will produce a state-of-the- art multimodel dataset designed to advance our knowledge of climate variability and climate change. Researchers worldwide are analyzing the model output and will produce results likely to underlie the forthcoming Fifth Assessment Report by the Intergovernmental Panel on Climate Change. Unprecedented in scale and attracting interest from all major climate modeling groups, CMIP5 includes “long term” simulations of twentieth-century climate and projections for the twenty-first century and beyond. Conventional atmosphere–ocean global climate models and Earth system models of intermediate complexity are for the first time being joined by more recently developed Earth system models under an experiment design that allows both types of models to be compared to observations on an equal footing. Besides the longterm experiments, CMIP5 calls for an entirely new suite of “near term” simulations focusing on recent decades...
12,384 citations
"A global assessment of the impact o..." refers methods in this paper
...We conducted this assessment at a time when a new set of global change scenarios was being released; the GCMs of CMIP5 (Taylor et al. 2011) with the Representative Concentration Pathways (RCPs; van Vuuren et al....
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...A comparison of our CMIP3 SRES A2 simulations to CMIP5 RCP8....
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...We conducted this assessment at a time when a new set of global change scenarios was being released; the GCMs of CMIP5 (Taylor et al. 2011) with the Representative Concentration Pathways (RCPs; van Vuuren et al. (2011)) and the Shared Socio-economic Pathways (SSPs; Kriegler et al. (2012))....
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...5 SSP3 (see Online Resource 14 formethods and results) suggests that our conclusions are robust across theCMIP3 and CMIP5 models because the estimates of water scarcity are broadly consistent....
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Netherlands Environmental Assessment Agency1, Utrecht University2, Joint Global Change Research Institute3, National Institute for Environmental Studies4, International Institute of Minnesota5, Pacific Northwest National Laboratory6, University of Maryland, College Park7, National Center for Atmospheric Research8, Potsdam Institute for Climate Impact Research9, Vienna University of Technology10, Electric Power Research Institute11
TL;DR: The Representative Concentration Pathways (RCP) as discussed by the authors is a set of four new pathways developed for the climate modeling community as a basis for long-term and near-term modeling experiments.
Abstract: This paper summarizes the development process and main characteristics of the Representative Concentration Pathways (RCPs), a set of four new pathways developed for the climate modeling community as a basis for long-term and near-term modeling experiments. The four RCPs together span the range of year 2100 radiative forcing values found in the open literature, i.e. from 2.6 to 8.5 W/m 2 . The RCPs are the product of an innovative collaboration between integrated assessment modelers, climate modelers, terrestrial ecosystem modelers and emission inventory experts. The resulting product forms a comprehensive data set with high spatial and sectoral resolutions for the period extending to 2100. Land use and emissions of air pollutants and greenhouse gases are reported mostly at a 0.5×0.5 degree spatial resolution, with air pollutants also provided per sector (for well-mixed gases, a coarser resolution is used). The underlying integrated assessment model outputs for land use, atmospheric emissions and concentration data were harmonized across models and scenarios to ensure consistency with historical observations while preserving individual scenario trends. For most variables, the RCPs cover a wide range of the existing literature. The RCPs are supplemented with extensions (Extended Concentration Pathways, ECPs), which allow
6,169 citations
"A global assessment of the impact o..." refers methods in this paper
...We conducted this assessment at a time when a new set of global change scenarios was being released; the GCMs of CMIP5 (Taylor et al. 2011) with the Representative Concentration Pathways (RCPs; van Vuuren et al. (2011)) and the Shared Socio-economic Pathways (SSPs; Kriegler et al. (2012))....
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TL;DR: In this paper, an updated gridded climate dataset (referred to as CRU TS3.10) from monthly observations at meteorological stations across the world's land areas is presented.
Abstract: This paper describes the construction of an updated gridded climate dataset (referred to as CRU TS3.10) from monthly observations at meteorological stations across the world's land areas. Station anomalies (from 1961 to 1990 means) were interpolated into 0.5° latitude/longitude grid cells covering the global land surface (excluding Antarctica), and combined with an existing climatology to obtain absolute monthly values. The dataset includes six mostly independent climate variables (mean temperature, diurnal temperature range, precipitation, wet-day frequency, vapour pressure and cloud cover). Maximum and minimum temperatures have been arithmetically derived from these. Secondary variables (frost day frequency and potential evapotranspiration) have been estimated from the six primary variables using well-known formulae. Time series for hemispheric averages and 20 large sub-continental scale regions were calculated (for mean, maximum and minimum temperature and precipitation totals) and compared to a number of similar gridded products. The new dataset compares very favourably, with the major deviations mostly in regions and/or time periods with sparser observational data. CRU TS3.10 includes diagnostics associated with each interpolated value that indicates the number of stations used in the interpolation, allowing determination of the reliability of values in an objective way. This gridded product will be publicly available, including the input station series (http://www.cru.uea.ac.uk/ and http://badc.nerc.ac.uk/data/cru/). © 2013 Royal Meteorological Society
5,552 citations
"A global assessment of the impact o..." refers background in this paper
...1 data set (Harris et al. 2012) for the 1961–1990 time horizon, which is approximately 0....
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...1 data set (Harris et al. 2012) for the 1961–1990 time horizon, which is approximately 0.3 °C above pre-industrial....
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TL;DR: Numerical experiments combining climate model outputs, water budgets, and socioeconomic information along digitized river networks demonstrate that (i) a large proportion of the world's population is currently experiencing water stress and (ii) rising water demands greatly outweigh greenhouse warming in defining the state of global water systems to 2025.
Abstract: The future adequacy of freshwater resources is difficult to assess, owing to a complex and rapidly changing geography of water supply and use. Numerical experiments combining climate model outputs, water budgets, and socioeconomic information along digitized river networks demonstrate that (i) a large proportion of the world's population is currently experiencing water stress and (ii) rising water demands greatly outweigh greenhouse warming in defining the state of global water systems to 2025. Consideration of direct human impacts on global water supply remains a poorly articulated but potentially important facet of the larger global change question.
4,355 citations
"A global assessment of the impact o..." refers background in this paper
...Alternative approaches have conducted analyses at the scale of individual grid cells (Oki and Kanae 2006; Vörösmarty et al. 2000), countries (Oki et al....
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...Alternative approaches have conducted analyses at the scale of individual grid cells (Oki and Kanae 2006; Vörösmarty et al. 2000), countries (Oki et al. 2001) and food production units (Kummu et al. 2010)....
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