Economic models are missing huge future risks from climate change, in part because no one knows how to quantify them, says a new study.

Risks for the world’s Transboundary River Basins are projected to increase in the next 15–30 years, particularly in four hotspot regions: the Middle East, Central Asia, the Ganges-Brahmaputra-Meghna basin, and the Orange and Limpopo basins in Southern Africa.

From aging and leaky pipes to pollution and shrinking aquifers, America’s water infrastructure faces a growing set of challenges. A new video describes how the America’s Water Initiative, a program based at the Columbia Water Center, is trying to address those issues.