The international committee overseeing the United Nations’ official climate scenarios has formally retired the RCP8.5 projection—along with its successors SSP5-8.5 and SSP3-7.0—declaring them “implausible.” The decision, made in connection with the CMIP7 modeling framework adopted earlier this month, marks the most significant change in climate-scenario practice since the IPCC’s Fifth Assessment Report. President Donald J. Trump celebrated the announcement on Truth Social on Friday, writing: “GOOD RIDDANCE!
After 15 years of Dumocrats promising that ‘Climate Change’ is going to destroy the Planet, the United Nations TOP Climate Committee just admitted that its own projections (RCP8.5) were WRONG! WRONG!
WRONG!” He added: “For far too long Climate Activism has been used by Dumocrats to scare Americans, push horrible Energy Policies, and fund BILLIONS into their bogus research programs.” RCP8.5 had served as the foundation for the most catastrophic climate projections since 2011. The scenario assumed a near-tripling of global coal use, no meaningful climate policy worldwide, and population growth far above any plausible trajectory. Despite these assumptions falling outside any realistic energy mix, RCP8.5 was treated as a “business-as-usual” baseline by national governments, central banks, and headline news coverage for more than a decade.
The retirement vindicates years of warnings from analysts who pointed out that real-world emissions were tracking nowhere near the scenario’s assumed pathway. The Network for Greening the Financial System, which guides more than 140 central banks, had calibrated its long-term climate-risk scenarios to RCP8.5.
National impact assessments in the United States, United Kingdom, Germany, Canada, Australia, and Japan all rested on the same input. Roger Pielke Jr., writing on his Substack and at the American Enterprise Institute, called the retirement “the biggest shift in climate science in decades.” He noted that the climate-research community had quietly known for years that the scenario was overheated while continuing to publish papers that used it as the headline finding. Independent analyses had long challenged the scenario’s assumptions.
Justin Ritchie and Hadi Dowlatabadi showed in Environmental Research Letters in 2018 that the emissions pathway to RCP8.5 would require a five-fold increase in global coal use by century’s end—an amount larger than several published estimates of recoverable coal reserves. In early 2020, Zeke Hausfather and Glen Peters published “Emissions: the ‘business-as-usual’ story is misleading,” urging the climate community to drop RCP8.5 as a baseline.
Dr. John Christy and Dr. Roy Spencer of the University of Alabama in Huntsville have maintained the UAH satellite temperature record since 1979. Their analysis comparing CMIP model ensembles against satellite observations has consistently shown the models running approximately 2–3 times hotter than reality in the troposphere. SSP3-7.0, the second scenario retired in the same decision, assumed a global population approaching 13 billion by 2100.
The United Nations’ own median projection sits at 10.4 billion. The International Energy Agency’s Stated Policies outlook now projects global annual energy-related CO2 emissions falling under 30 gigatonnes by 2050—a trajectory tracking the SSP1-3.4 forcing range, not anywhere near RCP8.5.
The CMIP7 framework that replaces RCP8.5 still includes a “high” scenario, but its central case is meaningfully lower than the now-retired one. Regulators and policymakers will face pressure to revisit standards calibrated to the old assumption, particularly those baked into financial-sector stress tests, ESG disclosure rules, and infrastructure planning. None of this changes the case for a cleaner planet.
Clean water, clean air, clean soil, reduced pollution, ecosystem restoration, and responsible stewardship of natural resources remain valuable on their own terms. The argument has never been whether the world should pursue those goals, but whether sweeping economic policy should be built on the assumption of an apocalyptic temperature trajectory that the committee itself now concedes was never plausible.
