China mines more bitcoin than anywhere else. The government wants that to stop

China has extended its iron-fisted crackdown on using and trading bitcoin to the industry that oversees the mining of new cryptocurrency tokens.

The new steps from Beijing were unveiled late on Friday. They roiled crypto markets over the weekend and pushed crypto miners to suspend some business in China, creating uncertainty about a critical step in the process needed to put more of these coins in circulation.

Chinese Vice Premier Liu He told a group of finance officials on Friday that the government would “clamp down on bitcoin mining and trading activity” as part of its goal to achieve financial stability. The government didn’t elaborate on specific policies targeting mining or trading.

While China has taken steps to restrict the use of cryptocurrencies for years, the focus on “mining” is new. The presence of Liu and other high-ranking cabinet members at the meeting, along with steps taken earlier last week to widen a clampdown on cryptos, indicate that the Chinese government is getting more aggressive about its approach.

Major crypto miners took notice. HashCow — which owns the world’s largest mining farms — said Saturday that it would stop selling machines to clients in China and refund anyone who already paid for a machine but did not receive it. (It added, though, that it would maintain existing crypto mining machines.)

“We will actively support all kinds of laws and regulations in the country to avoid regulatory risks,” the Chinese company said.

Another Chinese mining company, BIT.TOP, said it would no longer offer mining services for clients in mainland China.

“Next, we will mainly mine in North America,” wrote Jiang Zhuoer, CEO of BIT.TOP, on his Weibo account on Saturday. “It’s not worth running the regulatory risk.”

Such decisions could have big consequences for cryptos. For example, the value of bitcoin is in part determined by the finite number — 21 million — of coins that can be created. Not all of the coins are in circulation, and bitcoin “miners” use computers to solve complex puzzles to create a new “block” on the chain.

The computers necessary for that process are run by companies like HashCow and BIT.TOP. China accounts for more than 75% of bitcoin mining around the world, according to research published by the peer-reviewed journal Nature Communications last month.

In his Weibo post, Jiang of BIT.TOP said Friday’s meeting suggests that the government is trying to prevent a massive flow of capital into crypto mining, but individuals should still be allowed to mine on their own. He expected that half of the country’s mining machines could be suspended as a result of the latest actions, because the clampdown is focused on big mining farms.

Bitcoin and shares in crypto-related companies were shaken after China’s move.

Bitcoin prices fell as much as 13% on Sunday. The currency was last trading at around $36,000 per coin — far below the peak of $64,000 it reached a month ago, according to CoinDesk.

Shares of Chinese crypto mining firm BIT Mining plummeted 23% in New York on Friday. And Huobi Technology, a crypto exchange, plunged 22% on Monday in Hong Kong. Huobi, which provides miner hosting and other crypto-related products, said Monday that it would suspend services related to mining for new users in mainland China “to be more focused on the expansion of our overseas presence.” It added that most users would be unaffected by the change.

“Huobi always strives to abide by the evolving policies and regulations of each jurisdiction to adhere to risk and preserve the well-being of our users and their assets,” the company added.

“China once again showed who was the big fish, signaling a clampdown on crypto miners,” wrote Jeffrey Halley, senior market analyst for Asia Pacific at Oanda, in a Monday note. Regulatory risk “now represents an existential threat to the virtual currency space,” he added.

China has long limited crypto trading within the country, wary of financial risks associated with it. Last week, finance and banking watchdogs said that financial institutions and payment companies should not participate in any transactions related to cryptocurrency, nor should they provide crypto-related services to their clients.

The new measures aren’t just about curtailing financial risk. The computers needed for bitcoin mining eat up a ton of computing power and electricity, raising concerns about the cost to the environment.

In China alone, bitcoin is projected to generate more than 130 million metric tons of carbon emissions by 2024, according to the Nature Communications study. That’s more than the total annual carbon emissions output from the Czech Republic and Qatar in 2016.

That kind of output is also disastrous for China’s ambitious climate plans. President Xi Jinping has vowed to make his country carbon neutral by 2060, and the country is already struggling to contain carbon emissions from other industries.

Some authorities in China have cited the environmental concerns as a key reason for action. Inner Mongolia, for example, announced in February that it would end all crypto mining projects in the region by the end of April to cut down on emissions. The coal-rich province, which is a bitcoin mining hub because of its abundance of cheap energy, has set up hotlines to encourage residents to report on companies they suspect of being crypto miners.

— Jill Disis, Alexis Benveniste and Anneken Tappe contributed to this report.