President Donald Trump falsely claimed that the UN's top climate committee admitted a major emissions scenario is 'wrong,' sparking a wave of misinformation across social media and right-leaning outlets. In a weekend post, Trump wrote 'good riddance' to the RCP8.5 scenario, calling it 'wrong, wrong, wrong' and alleging the Intergovernmental Panel on Climate Change (IPCC) had just conceded as much. However, the IPCC does not create or oversee climate scenarios, and has made no such admission.
Trump's Claims and Their Spread
On 16 May, Trump posted on Truth Social that 'the Dumocrats and their Fake News Media partners have been using the RCP 8.5 Scenario... Wrong, Wrong, Wrong!' The term 'Dumocrats' is a derogatory nickname for Democrats. His comment was quickly amplified by The New York Post, The Daily Caller, and Fox News, many repeating the falsehood that the IPCC developed RCP8.5.
One outlet claimed that 'IPCC researchers revised their modelling approach last month, swapping the extreme pathway for seven alternative scenarios.' Another wrote that scientists had 'quietly scrapped apocalyptic forecasts.' These assertions are incorrect.
"The IPCC does not develop or own climate scenarios—it assesses published science. No IPCC document has ever called RCP8.5 'wrong'," said Dr. Zeke Hausfather, a climate scientist at Berkeley Earth and contributor to IPCC reports.
Background: What is RCP8.5?
RCP8.5 is a Representative Concentration Pathway that assumes very high greenhouse gas emissions throughout the 21st century, leading to approximately 8.5 watts per square meter of radiative forcing by 2100. It was developed by the scientific community, not the IPCC, and has been used in climate models to explore worst-case scenarios.
For years, critics argued RCP8.5 was unrealistic because it assumed continued heavy reliance on coal without significant climate policy. However, it remained a useful tool for studying high-risk outcomes and was never intended as a prediction.
Why the Debate?
Some researchers and media outlets have labeled RCP8.5 as alarmist, while others defend its role in risk assessment. The scenario has been replaced by a new set of 'Shared Socioeconomic Pathways' (SSPs) in the latest IPCC cycle, but this is a standard update, not a retraction.
What This Means
The new SSPs do not include an exact replica of RCP8.5's high emissions, but they still show that limiting warming to 1.5°C is 'not possible' without a significant 'overshoot'—a temporary exceedance of the target, according to Dr. Joeri Rogelj, a lead IPCC author. Projections suggest the world remains on track for 2.5–3°C warming, which the UN has called 'catastrophic.'
Trump's false claim distracts from the real news: the urgent need for emissions cuts. The IPCC's role is to synthesize science, not to own scenarios. Mischaracterizing this process undermines public understanding of climate risk.
"The transition from RCP8.5 to SSPs is a normal scientific progression. What hasn't changed is that our current trajectory is dangerous. That's the real story," said Dr. Katharine Hayhoe, climate scientist at Texas Tech University.
Next Steps and Implications
As the next IPCC reports incorporate SSPs, policymakers must recognize that even without RCP8.5, the risks of severe climate impacts remain high. Disinformation campaigns that downplay these risks could delay necessary action.
For a deeper dive, see our Background on IPCC scenarios and analysis of warming projections.