Bitcoin markets are pulling back after electric car manufacturer Tesla suspended its support for vehicle purchases using Bitcoin (BTC).

In a May 13 tweet, Tesla’s CEO Elon Musk noted the company’s concerns regarding the "rapidly increasing use of fossil fuels for Bitcoin mining and transactions, especially coal."

While Musk predicted that cryptocurrency "has a promising future,” he concluded that the rise of digital assets “cannot come at a great cost to the environment."

However, the firm has not ruled out accepting BTC again in the future, with the post noting that it will resume using Bitcoin "for transactions as soon as mining transitions to more sustainable energy." Musk added:

"We are also looking at other cryptocurrencies that use <1% of Bitcoin’s energy/transaction."

On social media, many within the crypto community have contradicted Musk and Tesla’s assertion regarding the environmental impact of Bitcoin mining, with The Wolf of All Streets host Scott Melker noting that "Miners primarily use renewable energy."

However, while the "3rd Global Cryptoasset Benchmarking Study" released by the University of Cambridge in October 2020 shows that up to 76% of cryptocurrency mining uses some renewable energy, it estimates that only 39% of the total power consumed by proof-of-work cryptocurrencies was green energy.

As of the time of writing, BTC has crashed roughly 6% in the past hour, tumbling from $54,800 to roughly $51,600.