Your ETH’s Carbon Footprint Just Shrank 99.98% — Here’s What Cambridge Found

If you’ve ever felt a twinge of guilt holding Ethereum because of old headlines about crypto mining “boiling the oceans,” a new report gives you permission to relax. The Cambridge Centre for Alternative Finance (CCAF) has found that Ethereum’s entire network now uses just 7.87 gigawatt-hours of electricity a year — a drop of more than 99.9% since the blockchain gave up energy-hungry mining back in 2022’s “Merge” upgrade.

To put that in perspective: CCAF says Ethereum’s yearly power use is now smaller than the London’s British Museum, which burns through about 16.18 GWh a year just running its lights and climate control. Before the Merge, Ethereum’s power draw approached 2.4 gigawatts continuously — a level the researchers describe as once “rivalling the electricity demand of a small country.” Today that’s fallen to roughly 0.90 megawatts.

Why this matters if you hold ETH

For years, one of the biggest criticisms leveled at Ethereum — and crypto generally — was environmental damage. Institutions, ESG-focused funds and everyday holders who cared about sustainability had a real reason to hesitate. This report is fresh, independent ammunition against that criticism, and it could matter for adoption: pension funds, corporations and governments weighing whether to hold or build on Ethereum often cite energy use as a factor in due diligence.

It also reinforces something Ethereum’s community has argued since the Merge: switching from “proof-of-work” (where miners burn electricity solving puzzles) to “proof-of-stake” (where validators simply lock up ETH to secure the network) wasn’t just a technical tweak. It fundamentally changed what Ethereum costs the planet to run — without changing what it costs you to use.

How Cambridge got its numbers

Rather than relying on theoretical estimates, CCAF physically audited 8,522 real nodes — the computers that store and relay Ethereum’s data — measuring actual wall-plug power draw across 20 different software setups. That produced a network-weighted average of about 105 watts per node, though the range varied widely: residential nodes people run from home used a median of just 18 watts, while enterprise-grade workstation setups drew closer to 152 watts.

It’s worth noting this node count is different from Ethereum’s roughly 894,000 validators, which are the entities economically staking ETH to secure the network. The report specifically clarifies these node operators are “distinct from the roughly 894,000 validators that secure the network economically” — the node count is what matters for the electricity math, not the validator count.

Geographically, the United States hosts 31% of Ethereum’s full nodes, followed by Germany (16%), Finland (8%) and France (6%) — together about 62% of all nodes. Hosting providers Hetzner, Amazon Web Services and OVH host roughly 40% of nodes between them, and about 64% of nodes run in cloud or data-center environments rather than someone’s spare room.

The emissions picture is even more dramatic

Because of the power drop, Ethereum’s estimated carbon emissions have fallen to just 2.37 kilotonnes of CO2-equivalent per year — a decline of about 99.98% from pre-Merge levels. CCAF compares that to “roughly the combined annual carbon footprint of 900 UK households,” and estimates that offsetting it entirely would take about 400 hectares of UK woodland, “roughly the size of Wimbledon.”

Sustainable sources — a mix of renewables (39.4%) and nuclear (17.0%) — now supply 56.4% of the electricity powering Ethereum’s infrastructure, above the global average of 43%. Natural gas remains the single largest source at 27.7%, reflecting the baseload power mix in the countries hosting most nodes.

None of this changes ETH’s price or your gas fees. But if environmental concerns were ever part of your decision to hold or avoid Ethereum, this is the clearest independent data yet that the network’s climate footprint is now genuinely small — smaller than a single museum, let alone a small country.