The world grows more than enough food to sustain the global population, but half of that food is wasted — and thus half of the water used in food production is wasted as well, says a new report from the United Nations Food and Agriculture Organization, International Water Management Institute, and Stockholm Water Management Institute. In developing countries, food spoils or is damaged by insects; in developed countries, it’s more often just tossed out. The United States and other industrialized countries throw out some 30 percent of their food each year, says the report: “That corresponds to [10.6 trillion gallons] of irrigation water, enough water to meet the household needs of 500 million people.” The organizations call for a 50 percent reduction in global food waste by 2025, pointing out that 1 billion people already live with insufficient water. “Unless we change our practices,” says the FAO’s Pasquale Steduto, “water will be a key constraint to food production in the future.”