In May 2023, the Environmental Protection Agency proposed to strengthen tailpipe emissions standards for greenhouse gas and criteria pollutants for both light-duty and medium-duty vehicles. The standards apply to vehicle model years beginning in 2027 and would increase in stringency through model year 2032.
In our comment letter, we explain that the Proposed Rule represents a sensible approach to cost-effectively reducing motor vehicle pollution that contributes to climate change and harms public health. We suggest that EPA take some additional steps to robustly support the regulation and ensure a complete presentation of benefits and costs. In particular:
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Our letter explains that the Proposed Rule lacks the indicators of history and breadth to trigger the major questions doctrine. We suggest that EPA catalog regulatory antecedents for its approach to considering vehicle electrification and provide additional context about the economic significance of the Proposed Rule. In particular, we suggest that EPA properly contextualize the rule’s effect on the full U.S. vehicle fleet rather than focus on new vehicle sales.
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Our letter explains that EPA thoroughly and robustly assesses regulatory benefits and costs. We suggest that EPA conduct additional analysis using the updated climate-damage valuations and social discount rates from draft guidance. As our letter illustrates, additional analysis around these parameters shows that the net benefits of the proposed program and its alternatives are even greater than EPA projects. We also suggest further analysis around other economic parameters.
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Our letter explains that EPA properly counts the value of fuel savings as a regulatory benefit. We suggest that EPA more clearly affirm that these standards help correct market failures that prevent consumers from optimizing fuel savings and that this “energy efficiency gap” remains even as electric vehicles become more prominent.
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Our letter recommends that EPA select the alternative that will maximize net social welfare, barring a compelling reason otherwise. Currently, EPA’s modeling concludes that the more stringent alternative would result in greater net benefits than the proposed program.
We also submitted joint comments with a coalition of other environmental groups on EPA’s use of the social cost of greenhouse gases in the Proposed Rule. In those comments, we offer extensive justification for the inclusion of global damages and the use of low discount rates. We also affirm that the Proposed Rule’s climate-damage valuations represent lower-bound estimates and recommend that EPA conduct additional analysis using draft updated valuations that it released late last year.