AI boom drives US gas-fired capacity past China, UK data centres raise emissions alarm

Global Energy Monitor (GEM) said the US is now building twice as much gas-fired capacity as China, and more than any other country, after a 76% increase in under-construction projects in the first half of this year. Overall US gas power capacity in development has ballooned by 50% since January, from 252GW to 378GW – a third of the global total. If all projects are built, the US gas fleet would increase by about two-thirds at a capital cost of more than $647bn. Around half of the new capacity is directly tied to datacentres for AI.

“Six months ago, China had more gas plants under construction but that has now flipped,” said Jenny Martos, a project manager at GEM. “There has been an enormous surge in datacenter proposals powered by gas in the past year and the climate implications of that is huge. Building all of this gas for AI locks in decades of pollution and it is also locking in dependence on a volatile fuel cost, which will get passed down to rate payers.”

The Trump administration has repeatedly claimed that China, the world’s largest carbon polluter, is expanding fossil fuel use so much that US emissions cuts would be futile. But the rush of AI infrastructure, combined with the administration’s demolition of environmental regulations and China’s rapid adoption of clean energy, is changing the equation. The International Energy Agency has forecast that US spending on coal- and gas-fired power plants will outstrip China’s for the first time in decades.

The stampede by tech companies such as Google, OpenAI and Amazon to build datacentres has contributed to a backlog of the most efficient gas turbines, leading several companies, including Elon Musk’s xAI, to switch to smaller, less efficient turbines that are more heavily polluting. Around two-thirds of more than 800 planned datacentres are located in drought-stricken areas, fueling local opposition. A Heatmap poll found three-quarters of Americans do not want to live next to a datacentre. Dozens of cities and counties have restricted new datacentres, and New York in July became the first state to enact a temporary ban on new hyper-scale datacentre permitting and construction.

Despite this backlash, Trump has championed datacentres and eliminated environmental reviews to speed them up. He said this month that “data centers could be bigger than oil” and urged state governors to cut taxes to encourage them. In separate remarks, he said communities that reject datacentres are making a mistake because they bring jobs and tremendous tax revenue.

In England, the non-profit group Foxglove has calculated that two planned datacentres – Wapseys Wood in Buckinghamshire and Quest Park in Bedfordshire – will use 1.3GW of power and produce more than 4.5m tonnes of carbon emissions per year when fully operational. That exceeds ExxonMobil’s 3.9m tonnes of UK emissions in 2023, according to the energy thinktank Ember. The datacentres are seeking to build their own on-site gas-fired power stations to avoid long grid connection waits.

A government spokesperson called the figures “misleading”, saying they assume both projects will run at 100% utilisation from day one, which was “not accurate”. Tom Hegarty of Foxglove said assuming 100% utilisation follows standard industry practice. Kierra Box of Friends of the Earth said it was “valid to look at those top level predictions” because datacentres aim to run at full capacity.

Caroline Lucas, former Green party leader, described the projected emissions as “absolutely horrifying”, saying it should ring alarm bells across government. Toby Perkins, a Labour MP and chair of the Commons environmental audit committee, called the analysis a “potent reminder” that datacentres could threaten the UK’s legally binding climate goals without proper measures. Oliver Hayes of Global Action Plan said the projects were “catastrophic for our carbon budgets”. Sam Hunter-Jones of ClientEarth said every megawatt powering a datacentre was a megawatt that could not replace fossil fuels elsewhere.

The two datacentres are among the first fast-tracked through the government’s nationally significant infrastructure project (NSIP) regime, which bypasses local planning authorities. Hayes said it was a “very worrying sign” that gas-fired datacentres were allowed into the NSIP regime, calling it an “affront to local people”. Lucas said fast-tracking insulates them from local scrutiny. A Department for Energy Security and Net Zero spokesperson said datacentres are vital and that the government would enable their growth by building unprecedented amounts of clean power. Wapseys Wood declined to comment and Quest Park did not respond.