The 2010s oil glut is a serious surplus of crude oil that started in 2014–2015 and accelerated in 2016, with multiple causes. They include general oversupply as US and Canadian shale oil production reached critical volumes, geopolitical rivalries amongst oil-producing nations, falling demand across commodities markets due to the deceleration of the Chinese economy, and possible restraint of long-term demand as environmental concerns steer an increasing share of energy consumption away from fossil fuels.