Roughly 2 billion people are at risk of declining water supplies in the northern hemisphere due to decreasing snowpack, according to Snowpack in the Lesser Caucasus mountains. researchers at Columbia’s Lamont-Doherty Earth Observatory. Researchers identified 97 basins with at least a two-thirds chance of declining water supplies. Nearly 1.45 billion people rely on snowpack in just 32 of those basins for a substantial proportion of their water. Among them are the basins of northern and central California, where much of U.S. produce is grown; the basins of the Colorado and Rio Grande rivers, which serve much of the American West and northern Mexico; the Atlas basin of Morocco; the Ebro-Duero basin, which feeds water to Portugal and much of Spain and southern France; and the volatile Shatt al Arab basin, which channels meltwater from the Zagros Mountains to Iraq, Syria, eastern Turkey, northern Saudi Arabia, and Iran.