A coalition of good-government and environmental organizations this week in a letter to state officials called for a moratorium on proof-of-working cryptocurrency mining in New York, pointing to the massive amount of energy used by the process. 

The letter from the New York Public Interest Research Group and Common Cause comes as the mining of cryptocurrency has drawn increased scrutiny from environmental advocates in areas of upstate New York like the Finger Lakes region. The letter also comes as lawmakers on Thursday in Congress held a public hearing on the issue.

"Proof-of-work cryptocurrency is an extremely energy-intensive process that requires thousands of machines whirring 24/7 to solve complex equations," the groups wrote in the letter. "The more machines that are running, the faster a coin is mined. Each one of these machines requires energy to run, plus more energy to run cooling technology." 

At the same time, the letter urged the Department of Environmental Conservation to deny the renewal of permits for an operation in the town of Dresden in Yates County. 

Advocates have raised concerns over the growing cryptocurrency mining industry and its energy usage that could make it harder for the state to meet its climate change goals of reducing carbon usage in the coming decades. 

"Allowing energy-intensive proof-of-work cryptomining to continue unchecked will make the CLCPA’s benchmarks virtually impossible to meet, and it will divert needed renewable power from the grid," they wrote in the letter. "Revitalizing old polluting power plants for private financial gain, with drastic consequences for our air and water, is now antithetical to the state constitution."