Water levels in the Yangtze hit a record low this week. Southern China is battling a drought with temperatures around the river exceeding 40C since last month. That spells trouble for Chinese hydropower and a tilt towards coal that will raise carbon emissions.
The world’s great rivers have been arteries for commerce and culture for millennia. This summer, some of them are in trouble. Water levels in the Rhine, Danube, Po and Colorado are unusually low.
The effects range from supply route disruption to crop failures. In parts of China, energy supplies are threatened as water used by hydropower plants dwindles. Water available from the main Three Gorges reservoir is already at half average levels.