As increased global temperatures are having a noticeable impact on the Earth’s water cycle, researchers at Michigan State University have found an increased likelihood of severe droughts in the next 30 years with unequal impacts on societies with low socioeconomic development.

“There is a growing interest, not only from [the] scientific community, but also [from] public policymakers about what will happen in the near future,” said Yadu Pokhrel, associate professor in the College of Engineering at MSU. “The frequency of droughts is increasing, and we have seen what is happening in California and Texas and many other global locations [in regard to water restrictions and availability].”

The research was published June 28 in Nature Communications.

River flow and greenhouse gas emissions

Pokhrel and the research team used hydrological models driven by global climate models for the period of 1865-2100 to identify different possible scenarios of future drought occurrence and severity. They generated two million different combinations of projected outcomes. One of the first indicators of drought conditions is unusually low river flow because there is not enough water funneling into the river. For the first time, the research team estimated the timing of first emergence of unprecedented drought that would last for at least five years. They provided these findings for both high and low greenhouse gas emissions scenarios to evaluate the role and consequence of society’s contribution to address climate change impacts.

“Places like southwestern South America, Mediterranean Europe and northern Africa are likely to see unprecedented drought in the next 30 years or so,” Pokhrel said. “These areas are particularly vulnerable, and we expect to see these changes continue in 30, 40 or 50 years.”

Other regions, such as the southwestern U.S., are also expected to experience more of such unprecedented droughts by the mid-21st century.

“Another important finding of the study is that there are differences in timing of unprecedented droughts under different emission scenarios,” Pokhrel said. “Meaning that we could delay such droughts substantially in time if we chose to go with low emissions pathways.”

Socioeconomic development

In a separate study, Pokhrel’s graduate student, Ahmed Elkouk, found that such increased occurrence of droughts in the future would disproportionately affect populations in countries with low socioeconomic development status, especially those located in Asia and sub-Saharan Africa. Yet, countries with high socioeconomic development, such as the United States, can play a role in reducing the severity of drought impacts by implementing policies that encourage lower emissions. Elkouk says, “Such efforts to reduce emissions, combined with improved socioeconomic development in the less developed world, are keys to reducing future drought risk.”

This research was published May 28 in the Journal of Environmental Management.

While Pokhrel and Elkouk’s research reveals how climate change is causing more drought conditions, Pokhrel and his team are advocating for more changes in climate change policies now to reduce future drought conditions, along with things individuals can do today to make a difference tomorrow.

“We need stricter and more climate mitigating measures in place,” Pokhrel said. “The individual person can help turn this around too by making choices to reduce their greenhouse gas emissions such as driving an electric car and there can be policies in place to reduce the financial burden on the consumer.