AG Rob Bonta filed a brief urging the United States Supreme Court to affirm the court of appeals’ decision in Diamond Alternative Energy LLC v. Environmental Protection Agency. The case concerns a waiver of preemption, granted by the U.S. Environmental Protection Agency (EPA) in 2013, which authorized the California Air Resources Board (CARB) to enforce standards—promulgated in 2012—requiring automakers to reduce greenhouse-gas emissions and increase production of zero-emission vehicles. Petitioners, who are in the oil and biofuel industries, did not challenge the waiver when it was first issued. Instead, they filed their challenge nearly a decade later, after the federal waiver was reinstated in 2022 following an unlawful rescission in 2019. Petitioners argued that the reinstated waiver exceeded EPA’s authority under federal law. Attorney General Bonta, with Governor Gavin Newsom and the California Air Resources Board, led a group of States and local governments to intervene in the case to defend against the challenge. In April 2024, the U.S. Court of Appeals for the District of Columbia Circuit dismissed the challenge, ruling that the petitioners lacked legal standing. That was because by the time petitioners’ case began, automakers were producing large numbers of zero-emission vehicles due to consumer demand and the automakers’ past investments, and petitioners failed to show that judicial relief would likely redress their asserted harm by increasing fuel sales.

Attorney General Bonta Urges U.S. Supreme Court to Affirm Decision Dismissing Challenge to Clean Air Act Waiver | State of California – Department of Justice – Office of the Attorney General