Cryptocurrency mining consumed an estimated 120 terawatt-hours of electricity in 2023, roughly equal to the entire annual electricity consumption of a country like Greece or Australia. That energy demand, along with carbon emissions, water use, and mountains of discarded hardware, makes crypto one of the most resource-intensive digital technologies ever created.
How Mining Burns Through Electricity
The environmental problem starts with how many cryptocurrencies verify transactions. Bitcoin and other coins that use a system called “proof of work” require miners to run powerful computers around the clock, racing to solve complex mathematical puzzles. The first miner to solve the puzzle earns the right to add a new block of transactions to the blockchain and collect a reward. Every other miner’s energy was spent for nothing. This competitive process is intentionally wasteful by design: the difficulty exists to keep the network secure.
The Cambridge Bitcoin Electricity Consumption Index estimates global Bitcoin mining used between 67 and 240 TWh in 2023, with a best estimate of 120 TWh. That represents roughly 0.2% to 0.9% of all electricity consumed worldwide. The United States alone accounts for about 38% of global mining activity, meaning American Bitcoin miners use somewhere between 25 and 91 TWh per year. The low end of that range equals the annual electricity consumption of entire states like Utah or West Virginia.
Carbon Emissions and the Fossil Fuel Mix
All that electricity translates directly into carbon dioxide. One 2020 analysis from the Dutch central bank estimated the Bitcoin network produced 45 megatons of CO₂ that year, with a single Bitcoin transaction carrying a footprint of about 402 kilograms of CO₂. A more recent 2023 estimate puts total cryptocurrency emissions (Bitcoin plus all other coins) at roughly 90.6 million metric tons of CO₂ equivalent, or about 0.25% of global emissions.
The energy mix powering mining operations has shifted in recent years. A 2025 Cambridge study found that sustainable energy sources now account for 52.4% of Bitcoin mining’s power, up from 37.6% in 2022. That includes 42.6% from renewables like hydropower and wind, plus 9.8% from nuclear. Natural gas has surged to 38.2% of the mix (up from 25% in 2022), while coal has dropped sharply from 36.6% to just 8.9%. The coal decline is significant, but nearly half the network still runs on fossil fuels, and the sheer scale of consumption means even a partially renewable grid produces enormous absolute emissions.
Water Consumption Most People Overlook
Electricity generation and data center cooling both require substantial amounts of water, and crypto mining is no exception. In 2023, the combined water footprint of all cryptocurrency mining was estimated at roughly 1.86 billion cubic meters. That volume could meet the basic drinking water and sanitation needs of a large portion of the global population that currently lacks access. Bitcoin alone accounted for about 808 million cubic meters of that total.
Without significant changes, projections suggest these figures could increase sixfold by 2030, pushing total crypto water consumption toward 13 billion cubic meters per year. In regions already facing water stress, large mining facilities competing for local resources pose a real concern.
The E-Waste Problem
Mining hardware has an unusually short useful life. The specialized chips used for Bitcoin mining (called ASICs) are designed to do one thing: solve the specific puzzle Bitcoin requires. As newer, faster machines come to market, older ones become unprofitable and worthless almost overnight. There’s no repurposing them for other computing tasks.
This cycle of rapid obsolescence generated an estimated 30,700 metric tons of electronic waste per year as of mid-2021. At peak Bitcoin prices earlier that year, projections suggested e-waste could climb beyond 64,400 metric tons. These devices contain metals and materials that, without proper recycling, end up in landfills leaching toxic substances into soil and groundwater.
Higher Electricity Bills for Neighbors
When a large mining operation moves into a community, it can strain the local power grid enough to raise prices for everyone nearby. Research from the University of Chicago found that in Upstate New York, the arrival of crypto miners drove household electricity bills up by an average of $88 per year and small business bills up by $168 per year. In total, Upstate New York households paid an extra $204 million annually, and small businesses paid an additional $92 million, simply because miners were consuming so much local electricity.
These costs hit communities that often see little direct economic benefit from mining operations, which tend to employ relatively few people while consuming enormous amounts of power.
Not All Cryptocurrencies Are Equal
The environmental damage is concentrated in proof-of-work cryptocurrencies, especially Bitcoin. An alternative approach called “proof of stake” selects transaction validators based on how many coins they hold and are willing to lock up as collateral, rather than forcing computers to compete through raw processing power. This eliminates the energy arms race entirely.
Ethereum, the second-largest cryptocurrency, switched from proof of work to proof of stake in September 2022 in an event called “the Merge.” The results were dramatic: Ethereum’s annual energy consumption dropped from about 25.7 TWh to a tiny fraction of that, reducing global energy consumption by 0.11% in a single software update. Proof-of-stake cryptocurrencies are now widely considered environmentally neutral compared to their proof-of-work counterparts.
Bitcoin, however, has no plans to make a similar switch. Its community views proof of work as fundamental to the network’s security and decentralization, meaning Bitcoin’s energy consumption will likely continue scaling with its price and adoption.
How Crypto Compares to Traditional Finance
Defenders of Bitcoin often point out that the traditional banking system uses energy too. And it does: one estimate puts the global banking system’s electricity consumption at roughly 264 TWh per year, accounting for data centers, bank branches, ATMs, and card networks. Gold mining uses an estimated 241 TWh per year. Bitcoin, at around 114 TWh, consumes less than either one individually.
But this comparison can be misleading. The banking system serves billions of people and processes orders of magnitude more transactions. Bitcoin handles roughly 112 million transactions per year. Visa alone processes over 200 billion. On a per-transaction basis, Bitcoin’s energy and carbon costs dwarf those of conventional payment systems by a factor of thousands.
Flare Gas and Other Mitigation Efforts
Some mining operations are experimenting with ways to reduce their footprint. One approach involves setting up mining rigs at oil fields where natural gas is being flared (burned off as waste). Instead of releasing that gas directly into the atmosphere, miners use it to generate electricity on-site. The gas still produces CO₂ when burned, but it creates economic value in the process and can be paired with carbon capture technology that reinjects CO₂ into the oil reservoir. Globally, oil companies flare about 145 billion cubic meters of gas per year, producing roughly 350 million tons of CO₂. Converting even a fraction of that into mining power could paradoxically lower emissions at those sites.
Other miners are deliberately locating near hydroelectric dams, wind farms, or solar installations where excess renewable energy would otherwise go unused. These efforts are real, and the rising share of sustainable energy in Bitcoin mining reflects genuine progress. But the fundamental problem remains: proof-of-work mining is designed to consume as much energy as the economics will support. As Bitcoin’s price rises, so does the incentive to mine, and total energy consumption grows accordingly, regardless of the energy source.