Jan 12 2021
Researchers from Michigan State University (MSU) are heading an international effort to provide the first global view of the effect of climate change on drought severity and water availability in the upcoming years.
Yadu Pokhrel, associate professor of civil and environmental engineering in MSU’s College of Engineering. Image Credit: Michigan State University.
Toward the late 21st century, the global population and land area experiencing severe droughts are estimated to increase by more than two-fold— increasing from 3% between 1976 and 2005 to 7%–8%, stated Yadu Pokhrel, the lead author of the study and an associate professor of civil and environmental engineering in MSU’s College of Engineering. The study was published in the Nature Climate Change journal.
More and more people will suffer from extreme droughts if a medium-to-high level of global warming continues and water management is maintained at its present state. Areas of the Southern Hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this increase in water scarcity will affect food security and escalate human migration and conflict.
Yadu Pokhrel, Study Lead Author and Associate Professor, Civil and Environmental Engineering, College of Engineering, Michigan State University
The research group, which includes Farshid Felfelani, a postdoctoral researcher from MSU, and over 20 contributing authors from Japan, China, and Europe, is predicting a massive reduction in natural land water storage in as much as two-thirds of the world; this large reduction was also induced by climate change.
Land water storage, technically called terrestrial water storage, or TWS for short, is the build-up of water in rivers, ice and snow, lakes and reservoirs, soil, wetlands, and groundwater—all crucial components of water and energy supply in the world. TWS modulates the water flow inside the hydrological cycle and establishes the availability of water and also drought.
Our findings are a concern. To date, no study has examined how climate change would impact land water storage globally. Our study presents the first, comprehensive picture of how global warming and socioeconomic changes will affect land water storage and what that will mean for droughts until the end of the century.
Yadu Pokhrel, Study Lead Author and Associate Professor, Civil and Environmental Engineering, College of Engineering, Michigan State University
According to Felfelani, the study has provided the international team with a significant prediction opportunity.
Felfelani added, “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.”
The study is based on a set of 27 global climate-hydrological model simulations covering 125 years and was performed under a global modeling project, known as the Inter-Sectoral Impact Model Intercomparison Project. Pokhrel is also a working member of the study.
Our findings highlight why we need climate change mitigation to avoid the adverse impacts on global water supplies and increased droughts we know about now. We need to commit to improved water resource management and adaptation to avoid potentially catastrophic socio-economic consequences of water shortages around the world.
Yadu Pokhrel, Study Lead Author and Associate Professor, Civil and Environmental Engineering, College of Engineering, Michigan State University
Journal Reference:
Pokhrel, Y., et al. (2021) Global terrestrial water storage and drought severity under climate change. Nature Climate Change. doi.org/10.1038/s41558-020-00972-w.