A cloud of methane was detected by satellite near coal mines in South Africa, drawing attention to a lesser-known environmental risk that comes from using the dirtiest fossil fuel. The potent greenhouse gas — methane traps roughly 84 times more heat than carbon dioxide in its first two decades in the atmosphere — was emitted at an estimated rate of 65 metric tons an hour on May 10, according to Kayrros SAS. The Paris-based analytics company found the leak by parsing European Space Agency satellite observations. It was the worst plume of methane Kayrros detected in the data over Africa this year.
