Climate change hot spots of water stress and hydropolitical conflict

Abstract:

Three hundred and ten large basins in the world straddle at least one international border. Many of these transboundary basins have experienced hydropolitical discord ranging from treaty disagreements to outright military conflict. Future changes in hydrology have the potential to strain international relations. We present projections of changes in water availability in 30 major transboundary river basins around the globe by the end of the 21^st century. Our analyses are based upon an ensemble of runoff simulations from the Coupled Model Intercomparison Project Phase 6. We calculate the projected changes in water availability by evaluating changes in the mean and intra-annual range of monthly runoff. We assess these changes across political boundaries, estimating how countries within each basin differ in their responses. By comparing the disparate signals of change (i.e. increasing or decreasing water availability), we infer basins with potential of conflict over water resources. We then combine these findings with existing datasets of hydropolitical tension to identify hot spots of potential conflict over water resources. The findings highlight basins worthy of finer scale hydrologic climate change research in support of planning. Anticipating these changes could promote collaboration to mitigate risks of hydropolitical conflict.