Government revises July 2025 projections for AI-driven datacentre carbon footprint upwards by around 100x, but Carbon Brief suggests the numbers could be much higher stillThe UK government’s projections for the carbon footprint of data centres have been significantly underestimated, according to recent revisions. The revised figures, which were published last week, suggest that the carbon output from electricity usage by data centres could be up to 100 times higher than initially projected. This revelation has sparked a wave of concern and debate about the environmental impact of our increasing reliance on digital technology.
In July of last year, the Department for Science, Innovation & Technology (DSIT) released its Compute evidence annex. This document outlined the future of AI, compute demand, and the implications for the carbon footprint. The DSIT estimated that by 2035, the UK’s greenhouse gas emissions from AI compute could range from 0.025 to 0.142 MtCO₂, which is less than 0.05% of the UK’s projected total emissions.
However, in a recent correction to the document, the DSIT revised these figures significantly. The revised estimate suggests that the UK’s cumulative 10-year greenhouse gas emissions from AI compute could range from 34 to 123 MtCO₂. This represents around 0.9-3.4% of the UK’s projected total emissions over the next decade. The discrepancy between the initial and revised figures is staggering, with the revised estimate being around 100 times higher.
This miscalculation has raised eyebrows in the scientific community. An analysis by the climate change science and policy research group, Carbon Brief, suggests that even the revised figures might be overly optimistic. The government’s target is to achieve 50gCO2/kWh by 2030 through the use of clean energy sources such as wind, nuclear, hydro, and solar power. However, research conducted by Carbon Brief and environmental campaigners Foxglove indicates that this target may be unattainable if any of the power generation needs to be gas-powered. Gas-powered electricity generation has a carbon intensity that is around 10 times higher than that of clean energy sources.
Carbon Brief’s calculations suggest that emissions could range from 3.4 MtCO₂ if 5% of the electricity is gas-generated, to 68.1 MtCO₂ if 95% of the electricity is gas-generated. The higher figure is comparable to the annual carbon emissions of Sweden. This estimate is based on a recent projection by Ofgem, the government regulator for gas and electricity markets in Great Britain, which predicts a future data centre electricity demand of 20GW.
This projection is based on research conducted by the National Energy System Operator, which surveyed customers about their future grid connection requirements. The scale of this demand is illustrated by the peak demand in February 2026, which was 45GW.
Tim Squirrell, the head of strategy at Foxglove, expressed concern about the implications of these figures. He pointed out that the government has a legally binding commitment to reach net zero emissions by 2050. However, the rapid expansion of AI data centres, which could potentially double the country’s electricity consumption, seems to be at odds with this commitment.
The situation, as revealed by the revised figures, is much more serious than initially thought. The miscalculation of the carbon footprint of data centres underscores the urgent need for a more sustainable approach to digital technology. As we continue to rely more heavily on digital technology, it is crucial that we find ways to minimise its environmental impact. This will require a concerted effort from government, industry, and consumers alike.
