Summary

Amid growing concerns over the impacts of climate change on worldwide water security, Bitcoin’s water footprint has rapidly escalated in recent years. The water footprint of Bitcoin in 2021 significantly increased by 166% compared with 2020, from 591.2 to 1,573.7 GL. The water footprint per transaction processed on the Bitcoin blockchain for those years amounted to 5,231 and 16,279 L, respectively. As of 2023, Bitcoin’s annual water footprint may equal 2,237 GL.

The estimated power demand of the Bitcoin network reached a new all-time high in March 2023,7 suggesting an annualized total electricity consumption of 141.9 terawatt-hours (TWh). This represents a 35% increase compared with the total estimated electricity consumption of 104.9 TWh in 2021 (Data S1, sheet 4). Consequently, the water footprint of Bitcoin may have increased by a similar magnitude. Assuming a constant water intensity of electricity consumption (15.76 L per kWh) since January 2022, 141.9 TWh of electrical energy consumption could result in a water footprint of 2,237 GL (Data S1, sheet 4). With the network handling 113 million transactions in 2020 and 96.7 million in 2021, the water footprint per transaction processed on the Bitcoin blockchain for those years amounted to 5,231 and 16,279 L, respectively.

the total water footprint of US Bitcoin miners could be equivalent to the average annual water consumption of around 300,000 US households, comparable with a city such as Washington, DC.