San Francisco, July 17 : US Senator Elizabeth Warren (D-Massachusetts) and other Democrat leaders have asked the Environmental Protection Agency and Department of Energy in the US to crack down on crypto mining. They urged the authorities to ask crypto miners to provide data on emissions and energy use. Mining operations for Bitcoin, the largest cryptocurrency by market cap, are increasingly moving onshore, with the United States' share of global mining increasing from 4 per cent in August 2019 to nearly 38 per cent in January this year. The networks of Bitcoin and many other tokens are secured through a "proof of work" algorithm, which involves "miners" using highly-specialised and power-intensive computers known as "mining rigs" to verify transactions by solving a mathematical puzzle, with the winning miner being rewarded in new tokens. "Cryptomining facilities' energy consumption is also causing significant increases in energy costs for many small businesses and residents, the Senators wrote. They said that the results of their investigation, which gathered data from just seven companies, are disturbing. "Crypto miners are large energy users that account for a significant -- and rapidly growing -- amount of carbon emissions. Our investigation suggests that the overall US cryptomining industry is likely to be problematic for energy and emissions," said Warren. It is imperative that your agencies work together to address the lack of information about cryptomining's energy use and environmental impacts, and use all available authorities at your disposal," she added. The Senators asked the authorities to provide them with a staff-level briefing on this matter by no later than August 15. /IANS