Nearly 1 billion people lack reliable access to clean drinking water today. A report by the Water Resources Group projects that by 2030 annual global freshwater needs will reach 6.9 trillion cubic meters – 64 percent more than the existing accessible, reliable, and sustainable supply. This forecast, while alarming, likely understates the magnitude of tomorrow’s water challenge, as it does not account for the impacts of climate change.

While the Intergovernmental Panel on Climate Change (IPCC) forecasts an increase in total precipitation at the global level, regional patterns will vary significantly. Rainfall is projected to decline by more than 20 percent across North Africa, the Middle East, central Mexico, Central America, the Caribbean, Southern Africa, the eastern Amazon basin, and western Australia. The IPCC also forecasts a 90 percent likelihood that rainfall variability will increase, leading not only to more numerous dry spells, but also more extreme precipitation events and flooding.

Water’s critical role in the survival of human life, combined with imminent changes in its relative abundance, has understandably generated concern that it will be a cause of future conflict. The prospect of conflict over water is most clear in river basins where surface freshwater is shared between two or more states. In these cases, water constitutes a common pool resource whose consumption is rival: Uganda’s increasing consumption of Nile waters necessarily leaves downstream countries like Egypt and Sudan with less.

But contrary to popular belief, a new study by Colleen Devlin and I finds that water variability, rather than scarcity, may be the biggest climatic driver of interstate conflict.

For the complete article, please see New Security Beat.