Once shunned as a murky domain for cranks and criminals, bitcoin has started to attract mainstream investors. Its price has surged from less than $1,000 at the start of the year to above $16,000 on Thursday.
Critics say the cryptocurrency is a “fraud” and they warn of a bubble. Environmentalists worry about another risk — that it’s seriously hurting efforts to combat climate change.
“Bitcoin is slowing the effort to achieve a rapid transition away from fossil fuels,” meteorologist Eric Holthaus wrote in an article on environmental news site Grist this week.
Unlike the dollar or the pound, these virtual “coins” aren’t tied to a central bank. Instead, bitcoins are “mined” by computers in vast data centers that guzzle huge amounts of energy.
Bitcoin uses about 32 terawatts of energy every year, enough to power about three million U.S. households, according to the Bitcoin Energy Consumption Index published by Digiconomist, a website focused on digital currencies.
By comparison, processing the billions of Visa () transactions that take place each year consumes the same amount of power as just 50,000 American homes, according to Digiconomist.
More worryingly, Bitcoin’s energy demands are set to explode.
“As bitcoin grows, the math problems computers must solve to make more bitcoin get more and more difficult,” which means more processing power is needed, Holthaus wrote.
And he made a startling forecast: Without a significant change in how transactions are processed, bitcoin could be consuming enough electricity to power the U.S. by the middle of 2019…