Congressional Democrats are calling on the Environmental Protection Agency and Department of Energy to address the recent proliferation of cryptocurrency mining within the US. In a letter sent Friday (via The Guardian), Senator Elizabeth Warren and five other lawmakers said the two agencies should work together to require crypto mining firms to disclose their energy use and emissions.

The request comes after the group recently completed an investigation that began at the start of the year. According to the letter, data collected from seven of the largest mining companies in the US, including Stronghold, Bitfury and Riot, indicates they can collectively use more than 1 gigawatt of electricity. Put another way, that’s almost enough to power all the residential buildings in Houston.

Warren and the other lawmakers say they’re concerned about what all that power use will mean for the environment and consumers. Regarding the former, they state that emissions data from three of the surveyed companies indicate they emit approximately 1.6 million tons of CO2 annually or the equivalent of the tailpipe emissions of almost 360,000 cars. “Bitcoin miners are using huge quantities of electricity that could be used for other priority end uses that contribute to our electrification and climate goals, such as replacing home furnaces with heat pumps,” the letter states.

On the latter point, the lawmakers cite a 2021 study from the University of California, Berkeley that estimated crypto mining in upstate New York raised annual electricity bills by approximately $165 million for small businesses and $79 million for consumers. What’s more, they say their investigation doesn’t even scratch the surface of the full impact of crypto mining on power use and emissions in the US. “None of the companies provided full and complete information in response to our questions,” they note.

“The results of our investigation, which gathered data from just seven companies, are disturbing, with this limited data alone revealing that crypto miners are large energy users that account for a significant – and rapidly growing – amount of carbon emissions,” the letter states. By requiring crypto mining firms to disclose their energy use and emissions, the group says the EPA and Department of Energy could provide lawmakers with better data to inform future policy decisions. The agencies have until August 15th to respond to the request.

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