Hydrological droughts in the 21st century, hotspots and uncertainties from a global multimodel ensemble experiment
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Authors
Colleges, School and Institutes
External organisations
- Department of Biology, Queens College and Graduate Center of the City University of New York, Flushing, New York 11367, USA.
- Tokyo Metropolitan University
- Centre for Material Cycles and Waste Management Research, National institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba, 305-8506 Ibaraki, Japan.
- UK Centre for Ecology and Hydrology
- University of Nottingham
- Reading University
- Centre for Ecology and Hydrology
- Department of Civil and Structural Engineering
- University of Maryland; Earth System Science Interxdisciplinary Center; 8082 Baltimore Avenue College Park Maryland 20740 USA
- RESEARCH INSTITUTE OF INDUSTRIAL SCIENCE
- Nees Institute for Plant Biodiversity, University of Bonn
- Walker Institute for Climate System Research
- Met Office
- City College of New York
- Wageningen University and Research Centre
- Potsdam Institute for Climate Impact Research
- Max Planck Institute for Meteorology
- University of Tokyo
- National Institute for Environmental Studies of Japan
- Department of Physical Geography
- Utrecht University
- Center for Development Research
- Institute for the Study of Earth, Oceans, and Space
- University of New Hampshire Durham
Abstract
Increasing concentrations of greenhouse gases in the atmosphere are expected to modify the global water cycle with significant consequences for terrestrial hydrology. We assess the impact of climate change on hydrological droughts in a multimodel experiment including seven global impact models (GIMs) driven by biascorrected climate from five global climate models under four representative concentration pathways (RCPs). Drought severity is defined as the fraction of land under drought conditions. Results show a likely increase in the global severity of hydrological drought at the end of the 21st century, with systematically greater increases for RCPs describing stronger radiative forcings. Under RCP8.5, droughts exceeding 40% of analyzed land area are projected by nearly half of the simulations. This increase in drought severity has a strong signal-to-noise ratio at the global scale, and Southern Europe, the Middle East, the Southeast United States, Chile, and South West Australia are identified as possible hotspots for future water security issues. The uncertainty due to GIMs is greater than that from global climate models, particularly if including a GIM that accounts for the dynamic response of plants to CO2 and climate, as this model simulates little or no increase in drought frequency. Our study demonstrates that different representations of terrestrial water-cycle processes in GIMs are responsible for a much larger uncertainty in the response of hydrological drought to climate change than previously thought. When assessing the impact of climate change on hydrology, it is therefore critical to consider a diverse range of GIMs to better capture the uncertainty.
Details
Original language | English |
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Pages (from-to) | 3262-3267 |
Number of pages | 6 |
Journal | National Academy of Sciences. Proceedings |
Volume | 111 |
Issue number | 9 |
Publication status | Published - 4 Mar 2014 |
Keywords
- Climate impact, Evaporation, Global hydrology, Global warming