News Feature | August 31, 2015

Global Warming Policies May Increase Water Deficits

Sara Jerome

By Sara Jerome,

Is it possible that emissions-curbing policies endanger the water supply even more than climate change itself?

“Using biofuels as a way to cut greenhouse gas emissions could put U.S. water resources under increasing pressure. Researchers find that a heavy reliance on bioenergy could mean a 42 percent increase in water consumption across the US by 2100,” The Carbon Brief reported.

That’s the takeaway from a new study from the University of Maryland and Pacific Northwest National Laboratory, published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS). The problem centers on emissions policies designed around biofuels.

“The results clearly show, for the first time to our knowledge, that climate change mitigation policies, if not designed with careful attention to water resources, could increase the magnitude, spatial coverage, and frequency of water deficits. The results challenge the general perception that mitigation that aims at reducing warming also would alleviate water deficits in the future,” the study said.

Lead author Mohamad Hejazi said the findings mean that water must be carefully considered in any policy intervention. “If we don’t pay careful attention to water, we could end up with climate mitigation policies that yield such negative consequences,” he said.

Responding To Climate Change (RTCC) broke down the meaning of the study: “Their models show that while mitigating climate change boosts water supply, this is outweighed by increased demand... In other words, green policies risk causing more water stress than climate change itself.”

It’s not the act of curbing emissions, but rather the use of thirsty bioenergy crops, that creates problems. “A scenario involving less bioenergy saw water demand rise 12 percent instead of 42 percent, with nuclear and geothermal energy the main drivers. But the authors noted bioenergy was seen as a cost-effective option, with potential for negative emissions if coupled with carbon capture and storage,” the study said.

Bioenergy crops are also criticized for taking up space that could be used for food crops.

For similar stories, visit Water Online’s Water Scarcity Solutions Center.