White House Publishes Proposed Amendment to National Climate Assessment

The Office of Science and Technology Policy released a proposed amendment to the Fifth National Climate Assessment on September 10, 2026. This action was taken on behalf of the U.S. Global Change Research Program and was published in the Federal Register.

The published amendment aims to change the way the highest-emission climate scenario, known as RCP8.5, is used in federal processes. According to the proposal, this scenario would be considered implausible and its use in government decision-making would be restricted.

The Fifth National Climate Assessment, which is a report required by Congress every four years, was last issued in 2023. The assessment is produced by the U.S. Global Change Research Program, a federal initiative that coordinates climate research across multiple agencies.

In April 2025, the administration dismissed over 400 scientists who had been working on the next National Climate Assessment. During the same period, the website that hosted both current and previous assessments was taken offline.

What the numbers show

• The Fifth National Climate Assessment was published in 2023.
• More than 400 scientists were dismissed in April 2025.
• The proposed amendment was published on September 10, 2026.

Matthew Wielicki was appointed to lead the U.S. Global Change Research Program, the office responsible for producing the National Climate Assessment. Wielicki is known for his critical views on climate science, according to media reports.

The proposed amendment specifically addresses the use of the RCP8.5 scenario, which represents the highest level of projected greenhouse gas emissions. The Office of Science and Technology Policy stated that the amendment seeks to limit the scenario's influence on federal policy and planning.

The publication of the amendment in the Federal Register marks the start of a formal process for considering changes to the National Climate Assessment. The proposed changes are subject to review and further action as outlined in federal procedures.

* This article is based on publicly available information at the time of writing.