Calif. Sues U.S. for Data that Justifies Emission Freeze

California is suing federal regulators to reveal the data they used to justify their plan to freeze emission standards at 2020 levels.

Current rules agreed to in 2012 by carmakers and the Environmental Protection Agency during the Obama administration aimed to tighten carbon dioxide emission limits through 2026. The result would drive up fuel economy averages from about 31 mpg in 2020 to 36 mpg by 2026.

An EPA reassessment completed in late 2016 declared those goals remained feasible. But the agency, working with the National Highway Traffic Safety Administration, came to the opposite conclusion four months later under the new Trump administration.

California says it filed the lawsuit in U.S. District Court in Washington, D.C., because the two regulators have not provided details to explain their about-face. The agencies say they will release their final plan by early June.

California, and more than a dozen states that follow its standards, also have vowed to impose the original CO₂ targets no matter what federal regulators decide. But the Trump administration aims to strip California of its Congressionally mandated power to do so.

Carmakers have been urging the two factions to find a compromise that would avoid a two-standard market in the U.S. The White House ended talks with California about the issue in February.