A Sierra Club analysis warns that U.S. power-sector carbon dioxide emissions could be 42% higher in 2030 than in 2025 if planned data centers are built and powered by additional fossil-fuel infrastructure—potentially reversing about 15 years of emissions reductions.

The projection comes as power-sector emissions have already begun rising again: after U.S. electricity emissions peaked in 2007 and declined as natural gas displaced coal and pollution rules took effect, emissions increased in 2025 amid low gas prices and the rollback of climate rules.

In the report’s upper-bound scenario, electricity-generation emissions would climb by 618 million tons by the end of the decade, about as much as the annual electricity-related carbon pollution of 128.8 million homes.

More than 460 million tons of projected 2030 emissions could come from power sources built separately from the grid, often by technology companies seeking to avoid connection delays—roughly equivalent to Mexico’s annual emissions.

The forecast is highly uncertain: outcomes depend on how many data centers are built, their technologies, renewable-energy deployment, grid connections, gas-turbine orders, and whether regulatory or community opposition delays or cancels projects.

Oracle’s Project Jupiter in New Mexico illustrates those risks; regulatory and community concerns have led the project to declare force majeure, highlighting how planned timelines and emissions estimates could change.

Industry groups dispute the projection, arguing that the report may overstate data centers’ potential emissions impact.

The findings have fueled debate over state responses, including proposed moratoriums on new data centers in Oklahoma and Louisiana; prediction-market activity has signaled greater expectations of an Oklahoma moratorium.

The listed odds vary by contract deadline: Oklahoma moratorium enactment ranged from 3.2% to 35%, while Louisiana ranged from 2.9% to 33.5%.

Observers are watching for legislation, statements from state officials, and regulatory reports that could show whether the moratorium proposals are gaining support or encountering resistance.

The article says the Trump administration is encouraging fossil-fuel infrastructure for data centers while rolling back pollution rules and stalling renewable-energy projects.

A separate Environmental Defense Fund report published in October 2026 found that the U.S. is planning more fossil-fuel power capacity than at any point in the previous decade.