A worker walks at a coal storage site near a freight station in Shenyang, Liaoning province October 18, 2010. REUTERS/Sheng Li LONDON (Reuters) – U.S. coal companies blame climate campaigners and the Obama administration for waging a war on coal that has cost thousands of jobs and threatened struggling mining communities. But coal’s long-term problems stem not from politics but from physical properties that make it an inferior source of energy compared with oil, gas and (arguably) renewables. Coal has been losing the “war” for market share since the middle of the 20th century as other sources of energy have become cheaper and more abundant. Rising energy consumption in advanced economies and emerging markets masked coal’s relative decline in the second half of the 20th century and first decade of the 21st. But as energy consumption has reached a plateau in developed countries, coal demand has started to decline […]