Preserving Truth in Climate Science Since 2000

Why This Archive Matters

The National Climate Assessment (NCA) is the most comprehensive, congressionally mandated review of climate science in the United States, produced roughly every four years. It influences policy, funding, infrastructure, and national security decisions, and is trusted by scientists, investors, and world leaders.

Today, that trust is under threat.

In August 2025, The Guardian reported that upcoming U.S. climate assessments will be overseen by individuals with direct ties to the fossil fuel industry, raising concerns that data could be altered, language softened, and scientific conclusions politically filtered.

The original NCA reports, once easily accessible, have already been removed from government websites.
We believe the public deserves full, unaltered access to the historical record, so PSCG is making them available here, in their original form.

The Reports

Below you can download every original National Climate Assessment since 2000, exactly as they were published:

NCA 2000 – Climate Change Impacts on the United States

National Climate Assessment Report 2000 | Original & Unaltered

NCA 2009 – Global Climate Change Impacts in the United States

National Climate Assessment – 2009 (Original Report)

NCA 2014 – Climate Change Impacts in the United States: The Third National Climate Assessment

Archived 2014 National Climate Assessment — full original text before any alterations.

NCA 2018 – Fourth National Climate Assessment, Volumes I & II

National Climate Assessment – 2018, Volume I (Original Report)

National Climate Assessment – 2018, Volume II (Original Report)

NCA 2023 – Fifth National Climate Assessment

National Climate Assessment – 2023 (Original Report)

What’s Next

When the altered versions of these reports are released under the new oversight, PSCG will publish:

1. Side-by-Side Comparisons – Highlighting every key change, omission, and language shift.

2. Bias Analysis – Identifying patterns of industry influence.

3. Policy Impact Assessments – Explaining how altered science could affect legislation, investment, and public safety.

Our goal: Protect the integrity of climate intelligence and ensure decision-makers have access to the truth, unfiltered.

Why This Is Urgent

• Altered data could weaken emissions targets.

• Softened language could delay climate action.

• Policy decisions based on incomplete science put lives, economies, and national security at risk.

Get Involved

• Share this page with scientists, journalists, and policymakers.

• Sign up for PSCG Updates to be notified when our Alteration Analyses go live.

• Contact PSCG if you have additional historical climate data that should be preserved.

Media & Research Inquiries: info@pscg.global; media@pscg.global