Sen. Tom Carper sent a letter May 1 to Secretary of the Department of Transportation Elaine Chao and Environmental Protection Agency Administrator Scott Pruitt calling on the officials to abandon their draft proposal to roll back fuel economy and greenhouse gas emissions standards, weakening them beyond the request of any automaker and preempting the historic authority of states, including California, to maintain independent standards under the Clean Air Act.

“I write to convey my deep concerns about a draft of a proposed rule obtained by my office from a non-governmental source that seeks to dramatically weaken vehicle fuel economy and greenhouse gas tailpipe standards. The document also states that California’s authority to set and enforce its own greenhouse gas tailpipe standards — as well as that of the 12 additional states, including Delaware, that have adopted them — is preempted by law,” wrote Carper.

“Such a proposal, if finalized, would harm U.S. national and economic security, undermine efforts to combat global warming pollution, create regulatory and manufacturing uncertainty for the automobile industry and unnecessary litigation, increase the amount of gasoline consumers would have to buy and runs counter to statements that both of you have made to members of Congress. I urge you to immediately disavow this proposal and instead work to negotiate a ‘win-win’ solution on federal fuel economy and tailpipe emissions standards that can be supported by both the automobile industry and the state of California,” wrote Carper.

The draft proposed rule obtained by the committee, among other things, shows DOT and EPA’s intent to:

— Weaken fuel economy standards by freezing model year 2020 standards through model year 2026.

— Exclude air conditioning refrigerant leakage, nitrous oxide and methane emissions from tailpipe CO2 compliance standards in all considered scenarios and proposing to phase-out similar credits from being used to comply with fuel economy standards in some considered scenarios.

— Preempt California’s authority to designate independent tailpipe greenhouse gas emissions standards under the Energy Policy and Conservation Act.

— Assert that the statutory requirement to consider energy conservation when setting fuel economy standards is no longer needed.

— Knowingly increase air pollution of nitrous oxide, sulfur dioxide, particulate matter, volatile organic compounds, resulting in “increased adverse health impacts — mortality, acute bronchitis, respiratory emergency room visits and work-loss days — nationwide.”

— Claim increased costs of fuel-efficient technologies without justification.

— Rely on several outdated and disproven assumptions about vehicle safety and driving habits.

— Minimize the impact of increasing fuel economy standards on greenhouse gas emissions and climate change tied to global temperatures, atmospheric concentrations of CO2, sea level rise and other impacts in 2100.

“This summary is by no means an exhaustive analysis of the draft of a proposed rule obtained by my office from a non-governmental source. It does, however, describe the administration’s plans to undertake a legally questionable, frivolous and fundamentally irresponsible path forward on an issue that is of vital importance to the environment, consumers, industry and hundreds of thousands of auto workers across the country. It also represents a clear departure from your stated commitments to Congress and the stated goals of automakers and the state of California for an inclusive negotiation. I urge you in the strongest possible terms to abandon this extreme and reckless approach and to put the administration on a more responsible path,” wrote Carper.

The text of the letter is available at bit.ly/2KtJmoY.