UK Data Centre CO2 Could Be 500x Government Estimate
Get the Energy newsletter
Daily energy & climate — solar, EVs, oil, the policy fights and tech bets shaping the transition. Free.
- Carbon Brief analysis found UK data centre CO2 emissions could be hundreds of times higher than the government's estimate, depending on how much of their electricity comes from gas.
- DSIT's official analysis estimated maximum emissions of 0.142 MtCO2 from 11.2GW of AI computing power by 2035, implying a carbon intensity of less than 2g CO2 per kWh — well below the government's own 50g/kWh 2030 target.
- Even if gas-fired electricity accounts for just 5% of data centre supply, emissions from 11.2GW would reach roughly 2MtCO2 — more than 10 times the government's top estimate for 2035.
- If data centre capacity hits the 20GW pipeline figure and relies heavily on gas, emissions could reach 70MtCO2, roughly Sweden's annual total and nearly 500 times the government's upper estimate.
- Dr Tim Squirrel of Foxglove called the DSIT figures "nonsense" and said they "threaten to derail our carbon budgets," arguing the projected compute simply cannot be built while producing the miniscule emissions calculated.
- After Carbon Brief contacted DSIT, the department deleted its emissions assessment and replaced it with a note stating the modelling was being "updated to ensure it reflects the most up to date assumptions."
- Companies have secured financial commitment for 71 new UK data centres requiring around 20GW of electricity — more than half of the UK's average 2025 demand of 37GW.
Why it matters: The UK government has quietly pulled its own emissions modelling for data centre expansion after it was challenged as implausibly low. With 71 new facilities in the pipeline potentially demanding 20GW — over half the UK's current average electricity load — the gap between DSIT's 0.05% figure and Carbon Brief's 20% projection could force a material revision to the 2035 carbon budget and complicate the 2030 clean power target. Developers have already turned to private gas supplies due to grid connection delays.
