The number of people suffering extreme droughts across the world will double in less than 80 years as a result of changes in climate and population, according to new research.
The University of Nottingham is part of a global research effort led by Michigan State University, which offers the first ever worldwide view of how climate change could affect water availability and drought severity in the decades to come.
Through hydrological model simulations by teams across the world, the researchers predict eight per cent of the global population will face extreme droughts by the late 21st century. The team projects that there will be a large reduction in natural land water storage in two-thirds of the world, also caused by climate change.
Land water storage, technically known as terrestrial water storage, or TWS, is the accumulation of water in snow and ice, rivers, lakes and reservoirs, wetlands, soil and groundwater — all critical components of the world’s water and energy supply. TWS modulates the flow of water within the hydrological cycle and determines water availability as well as drought.
The researchers also predict that areas of the Southern Hemisphere will be affected proportionally more. They say that some of these areas already have major water scarcity issues, which makes the results particularly concerning.
The study and its findings have been published in the journal Nature Climate Change, with more than 20 contributing authors from Europe, the US, China and Japan.
The set of 27 global climate-hydrological model simulations, spanning 125 years, was conducted under a global modelling project called the Inter-Sectoral Impact Model Intercomparison Project.
Simon Gosling, Professor of Climate Risk at the University of Nottingham, with Dr Hannes Müller Schmied of Goethe-University Frankfurt, led the coordination of the hydrological model simulations used in the study.
Our study is an early warning sign of what might happen if global greenhouse gas emissions are not reduced and it highlights the importance of rebuilding greener as we emerge from the pandemic. It is more important than ever to develop appropriate water management solutions for addressing the risk of more people exposed to droughts in the future.
Farshid Felfelani, postdoctoral researcher at Michigan State University said: “Recent advances in process-based hydrological modeling, combined with future projections from global climate models under wide-ranging scenarios of socioeconomic change, provided a unique foundation for comprehensive analysis of future water availability and droughts. We have high confidence in our results because we use dozens of models and they agree on the projected changes.”