Extreme Drought and Reduced Water Storage Will Increase if Climate Change Goes Unchecked
More land on Earth — and the people who live there — will face extreme drought in the coming decades, projects new research published in Nature Climate Change. The international research team found that by late 21st century, the land area subject to extreme drought could double to 7-8 percent from the 3 percent increase that happened during the 1976-2005 time period. Climate change is the leading contributor to this eventuality.
The study finds that a large reduction in land water storage could occur over two-thirds of the world, which creates scenarios with more drought and water scarcity. Land water storage is the build up of water in ice, snow and glaciers; rivers; lakes; wetlands; groundwater; and soil. Land water storage affects the flow of water globally, and determines water availability and drought.
According to Yadu Pokhrel, lead author and engineering professor at Michigan State University,
These declines in water storage and increases in future droughts are primarily driven by climate change, not land-water management activities such as irrigation and groundwater pumping.”
Even if greenhouse gas emissions are moderately lowered, the area of land broiling under extreme to exceptional drought is expected to jump from 3 to 7 percent, impacting around 500 million people up from 250 million, the study suggests. That means one out of 12 people might experience severe water shortages annually by 2100, when such shortages averaged out to one in 33 in the year 2000.
Water shortages are expected to be most pronounced in Australia, the Amazon River basin, Australia, southern Africa, the Mediterranean region and areas of the United States. In addition to greenhouse gas mitigation, better water management is necessary. This is especially in the parts of the Southern Hemisphere, where water scarcity currently exists, and where food security, political instability, migration and conflict could arise.