Scientists have warned that demand for bitcoin could single-handedly derail efforts to limit global warming, due to the huge amounts of energy taken to generate the digital currency.
Producing bitcoin at a rate that matches growing demand could by 2033 defeat the aim of limiting global warming to 2 degrees Celcius, according to US research published in the journal Nature Climate Change.
Last year, bitcoin production and usage emitted an estimated 69 million metric tonnes of carbon dioxide equivalent, the researchers said.
As the currency becomes more common, researchers said it could use enough electricity to emit about 230 gigatonnes of carbon within 15 years.
One gigatonne is equal to one billion metric tons of carbon.
Mining, the process of producing bitcoins by solving mathematical equations, uses high-powered computers and a lot of electricity, the researchers said.
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"Currently, the emissions from transportation, housing and food are considered the main contributors to ongoing climate change," said study co-author Katie Taladay in a statement. "This research illustrates that bitcoin should be added to this list."
Mining is a lucrative business, with one bitcoin currently selling for about €5,500.
"No matter how you slice it, that thing is using a lot of electricity. That means bad business for the environment," according to Camilo Mora, another co-author.
Bitcoin mining, however, is becoming more energy efficient, said Katrina Kelly-Pitou, research associate at the University of Pittsburgh.
She said bitcoin miners are moving away from sites such as China, with coal-generated electricity, to more environmentally friendly utilities in Iceland and the United States.