Severe droughts across the Northern Hemisphere—stretching from the farms of California to waterways in Europe and China—are further snarling supply chains and driving up the prices of food and energy, adding pressure to a global trade system already under stress. Parts of China are experiencing their longest sustained heat wave since record-keeping began in 1961, according to China’s National Climate Center, leading to manufacturing shutdowns owing to lack of hydropower. The drought affecting Spain, Portugal, France and Italy is on track to be the worst in 500 years, according to Andrea Toreti, a climate scientist at the European Commission’s Joint Research Center. In the American West, a drought that began two decades ago now appears to be the worst in 1,200 years, according to a study led by the University of California, Los Angeles. Researchers compare droughts by measuring the growth of annual tree rings that reflect rainfall and […]