Trump administration seeks to strip worst-case climate scenarios from 2023 assessment
The White House has proposed an amendment to the 2023 National Climate Assessment that would deem the highest-emission scenario, RCP8.5, implausible and bar its use in federal planning.
The Trump administration has filed an amendment to the National Climate Assessment 5, published in 2023, seeking to label the RCP8.5 high-emission pathway as implausible and to prevent its inclusion in federal decision-making. The change, drafted by the U.S. Global Change Research Program within the Office of Science and Technology Policy, cites a 2025 executive order that discourages reliance on “highly unlikely” assumptions.
Scientists, including Union of Concerned Scientists senior researcher Carlos Martinez, describe the effort as unprecedented and a violation of scientific integrity, noting that the assessment was produced by 14 agencies and hundreds of experts. California Attorney General Rob Bonta and other state officials have publicly opposed the move, while the CO2 Coalition’s chief executive Angela Wheeler welcomed it. The proposal has attracted roughly 100 comments, but the full comment list has not been released.
Why it matters
Altering the climate assessment could reshape federal infrastructure and disaster-planning policies across the United States.
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