Tesla owner Elon Musk has announced that the electric-car maker will no longer be accepting bitcoin in exchange for its vehicles due to the cryptocurrency's contribution to climate change. The U-turn comes after Tesla purchased $1.5 billion worth of bitcoin in February and announced that it would start accepting payments in the cryptocurrency in March. "We are concerned about rapidly increasing use of fossil fuels for Bitcoin mining and transactions, especially coal, which has the worst emissions of any fuel," Musk wrote on Twitter. "Cryptocurrency is a good idea on many levels and we believe it has a promising future, but this cannot come at great cost to the environment."