The Sierra Club estimates that US data center buildouts could wipe out 15 years of greenhouse gas emissions progress by 2030.

The Sierra Club, one of the oldest environmental preservation organizations in the U.S., estimates that by 2030, U.S. data center buildouts will emit as much carbon dioxide as all of Mexico, setting back progress on greenhouse gas reduction by 15 years, Bloomberg reports.

The Club's principal advisor for climate and energy, Jeremy Fusher, put it plainly: "the numbers continue to sort of boggle our minds." He was referring to an estimate that, including output from pending data center builds, the U.S. power sector will put 2.1 billion metric tons of CO2 into the atmosphere by the end of the decade, an increase of 42% over 2025 figures. The researchers' previous estimates were between a quarter and half of current projections.

A growing number of countries and states are passing laws requiring that a large share of power for new data centers come from green sources. These laws rarely apply retroactively, however, and often include phase-in periods. Ireland's law, for example, requires that new data centers be fed by 80% renewable power, but only six years after they begin operating.

In the current AI-driven market, construction speed is paramount. Roughly 40% of U.S. data centers are powered by natural gas turbines, and that is unlikely to change much. It will likely get worse, as green sources almost certainly won't keep pace with demand. Like RAM, GPUs, and storage, gas turbines have been snapped up by data center builders. Their prices have risen 50%, and production is backlogged for years, with one manufacturer opening production slots for 2032.

Brendan Pierpont of Energy Innovation, another climate-focused organization, notes that while the current path looks dangerous for the environment, it is hard to predict precisely how things will unfold. He points to common data center roadblocks, including turbine availability, delays in grid connections, and other factors that could slow construction.

It is indeed difficult to predict how many data centers will reach completion. Permit requests far exceed available grid capacity across the U.S., and a sizable number of projects face strong opposition. Meanwhile, although the AI bubble is still going strong, concerns are mounting about the economics of hyperscalers, suggesting some may go the way of the dodo, along with their projects.