30 January 2016

21st century United States emissions mitigation could increase water stress more than the climate change it is mitigating

Summary

There is evidence that warming leads to greater evapotranspiration and surface drying, thus contributing to increasing intensity and duration of drought and implying that mitigation would reduce water stresses. However, understanding the overall impact of climate change mitigation on water resources requires accounting for the second part of the equation, i.e., the impact of mitigation-induced changes in water demands from human activities. By using integrated, high-resolution models of human and natural system processes to understand potential synergies and/or constraints within the climate–energy–water nexus, we show that in the United States, over the course of the 21st century and under one set of consistent socioeconomics, the reductions in water stress from slower rates of climate change resulting from emission mitigation are overwhelmed by the increased water stress from the emissions mitigation itself. The finding that the human dimension outpaces the benefits from mitigating climate change is contradictory to the general perception that climate change mitigation improves water conditions. This research shows the potential for unintended and negative consequences of climate change mitigation.

Contact
Mohamad Hejazi
Publications
2015.  "21st century United States Emissions Mitigation could Increase Water Stress more than the Climate Change it is Mitigating."  Proceedings of the National Academy of Sciences 112(34): 10635-10640, doi:10.1073/pnas.1421675112.
Acknowledgments

This research is part of the Platform for Regional Integrated Modeling and Analysis (PRIMA) Initiative at Pacific Northwest National Laboratory (PNNL). It was conducted under the Laboratory Directed Research and Development Program at PNNL, a multiprogram national laboratory operated by Battelle for the US Department of Energy under Contract DE-AC05-76RL01830. This research also leveraged capabilities that were funded by the US Department of Energy, Office of Science, Biological and Environmental Research as part of the Integrated Assessment Research and Earth System Modeling programs.