UK government quietly revised AI datacenter carbon emissions estimate upward by over 100x, revealing climate impact 10 times larger than previously disclosed

The UK Department for Science, Innovation and Technology (DSIT) revised its estimate of CO₂ emissions from AI datacenters over the next decade from a maximum of 0.142 million tonnes per year to a range of 34–123 million tonnes total — a shift revealed this week after investigations by watchdog Foxglove and Carbon Brief. The higher figure equals roughly 0.9% to 3.4% of the UK's projected total emissions between 2025 and 2035.

AI datacenters consume far more electricity than conventional data storage facilities, and most of that power still comes from fossil fuels. The UK government had not performed basic arithmetic to measure this carbon footprint before committing to a major AI datacenter buildout as part of its economic growth strategy, according to critics including Foxglove's Tim Squirrell, who noted an unchecked expansion could double the country's entire electricity consumption.

For UK policymakers and businesses, this reveals a conflict: the government has a legally binding commitment to reach net zero by 2050, yet is aggressively pushing AI infrastructure that could trigger massive new emissions. Professionals in energy, climate policy, and tech investment now face uncertainty about whether these datacenters will be built as planned or face regulatory constraints. The lower estimate (34 million tonnes) assumes faster hardware efficiency gains and faster grid decarbonization — neither guaranteed.