Bitcoin's annual water footprint has been soaring as mining the cryptocurrency sucks up hundreds of billions of gallons, according to a researcher.

The peer-reviewed journal Cells Report Sustainability posted commentary last week from Alex de Vries, a doctoral candidate at the Vrije Universiteit Amsterdam, who estimated that bitcoin's water footprint will hit 591 billion gallons this year, up 278% from 2020.

"Bitcoin's expanding water footprint must be considered in the context of escalating water scarcity," he wrote, citing growing water issues in the western US and Kazakhstan, two large crypto mining regions.

Mining operations rely on computers to solve complex calculations to unlock new bitcoin tokens. As this is energy-intensive, water is used to cool the computer servers that run them as well as air-conditioning systems. Water is also indirectly consumed as it's used to cool power plants that provide electricity for miners.