Tesla hit the brakes Wednesday on letting people pay for electric cars with bitcoin, saying the computing-intense mining process of creating new cryptocurrency spews climate-harming emissions.
"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," Tesla chief executive Elon Musk said in a tweet.
"Cryptocurrency is a good idea on many levels and we believe it has a promising future, but this can not come at great cost to the environment."
Mining bitcoin has become a computing power battle, with machines devouring electricity while racing to sequence digital blocks in a chain.
Musk has touted a vision of Tesla making electric cars mainstream, shifting drivers away from combustion engines that pump out emissions that contribute to climate change.
In March, Tesla began officially accepting bitcoin as currency to purchase electric autos, further boosting the digital money.
Tesla in February first announced a plan to accept the cryptocurrency. The company also said it took a $1.5 billion investment in the digital money.
Musk said Tesla will not sell any of its bitcoin, and planned to eventually use the cryptocurrency when mining operations shift to more environmentally friendly energy use.
Tesla's February announcement, coupled with moves by MasterCard and other mainstream companies to accept the cryptocurrency, have helped to boost bitcoin to unprecedented levels in 2021.
Bitcoin was valued at $52,510 late Wednesday, below its record high.