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. NEws24 quotes Paris-based analytics companyKayrros SAS as saying that the cloud was spotted by parsing European Space Agency satellite observations about 125 kilometers east of Johannesburg in an area where Sasol has several coal mines as well as chemical and fuel operations. Kayrros said it was the the worst plume of methane detected in the data over Africa this year but Sasol said it didn’t record any elevated methane levels that day and that emissions from its mining operations “are highly diluted and dispersed over a wide geographical area.”