Water scarcity will increase around the world due to climate change, with more than 500 million people affected if mean global warming is limited to 2 degrees Celsius (3.6 degrees Fahrenheit), based on modeling studies by the Potsdam Institute for Climate Impact Research, or PIK.
An additional 8 percent of humankind may face new or worse water scarcity with 2 degrees warming, the target set by international climate negotiators, the German government-funded institute wrote in a news release today. That could reach 13 percent in the case of a 5-degree-Celsius rise, which is probable if climate change goes on unchecked, PIK said.
About 1.3 billion people already live in water-scarce regions, according to the institute. The institute calculated 152 scenarios using 19 climate change models, and said the projections for the affected population by 2100 carry a greater than 50 percent confidence.
“Our findings support the assertion that we are fundamentally destabilizing our natural systems,” Wolfgang Lucht, one of the study co-authors, was cited as saying in the statement. “We are leaving the world as we know it.”
A business-as-usual scenario modeled by the institute, with 5 degrees warming and a continued increase in the global population, would result in more than 1 billion additional people affected, PIK wrote.
Two degrees warming would cause “substantial” ecosystem changes in regions that cover 1 percent of the unique habitat of higher plant species, while at 5 degrees warming that would rise to 74 percent, according to the research. The results suggest the increasing impact of warming is nonlinear, the authors wrote.
“The findings clearly demonstrate that there is a large difference in the risk of global ecosystem change under a scenario of no climate change mitigation compared to one of ambitious mitigation,” Sebastian Ostberg, one of the study authors, was cited as saying.
Regions at risk in case of unchecked global warming include the grasslands of eastern India, the forests of northern Canada, the savannas of Ethiopia and Somalia and the Amazonian rain forest, according to the institute.