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Last Update: 10/26/2026 at 11:33 PM EST
High-Emissions Climate Scenarios
Coverage from The Star, Climate Depot, and others
High-emissions climate scenarios such as RCP8.
5 and SSP5-8.5 are modeling pathways, not predictions of what will happen. Their revision or retirement reflects changes in emissions trends, climate policy, and the rapid spread of technologies such as solar, wind, electric vehicles, and batteries, while high-end warming risks remain relevant for stress-testing decisions. The debate also concerns how institutions, media, and politicians interpret these scenarios, and whether lower estimates of the most extreme outcomes change the case for emissions cuts. IPCC assessments and related modeling continue to inform questions about heat, sea-level rise, food and water security, health, and economic damage.
Looking Back
114 Day Timeline
May 14
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All Articles32 articles
Important
Climate researchers updated international emissions scenarios, finding RCP8.5 less plausible but projecting nearly 3.5°C warming by 2100 globally.
7/30/2026 • Climate Science & Impacts • General
CMIP7 excludes RCP8.5 because emissions and demographic assumptions are judged implausible, reframing the highest scenario as an upper-bound exploration.
7/21/2026 • Climate Science & Impacts • General
Simon Watts asked New Zealand local councils on July 1, 2026 to stop using retired RCP8.5 and related scenarios in coastal hazard and planning decisions.
7/9/2026 • Climate Science & Impacts • General
Climate researchers describe how IPCC-linked RCP and SSP scenario inputs are processed through CMIP climate models to project warming, sea-level rise, and extreme-weather shifts.
6/24/2026 • Climate Science & Impacts • General
Detlef van Vuuren and Jennifer Morris discussed the CMIP-driven retirement of RCP8.5 and selection of a new high-end scenario feeding upcoming IPCC assessments.
6/10/2026 • Climate Science & Impacts • General
Detlef van Vuuren and colleagues publish an assessment in Geoscientific Model Development saying RCP 8.5 and SSP5-8.5 are implausible while high-end risk remains.
6/5/2026 • Climate Science & Impacts • General
In Europe, a 2025 scenario update discounts SSP5-8.5 but retains high-concern warming outcomes, increasing urgency for emissions cuts and resilience.
6/5/2026 • Climate Science & Impacts • General
Carbon Brief fact-checks Donald Trump claims about IPCC admissions of RCP8.5, clarifying CMIP and ScenarioMIP scenario development and updated emissions pathways.
5/19/2026 • Climate Science & Impacts • General
Updated emissions scenarios from the Scenario Model Intercomparison Project indicate continued-current-policies paths and climate-policy rollbacks would still drive severe risks while Paris-aligned outcomes require rapid cuts.
5/29/2026 • Clean Energy & Emissions • General
U.S. climate-assessment officials proposed limiting RCP8.5 and SSP5-8.5 as baseline planning scenarios after CMIP7 researchers identified the pathways as implausible in April 2026.
8/23/2026 • Climate Science & Impacts • General
Climate science analysts address climate disinformation after Donald Trump dismisses IPCC findings, clarifying RCP8.5 and scenario updates that still project severe warming under weak policy.
7/2/2026 • Climate Science & Impacts • General
van Vuuren et al. 2026 scenario work supports retiring RCP8.5/SSP5-8.5 for the next IPCC assessment as renewable costs and policy reduce baseline plausibility, while high-end warming remains uncertain.
5/18/2026 • Climate Science & Impacts • General
Detlef van Vuuren and other international climate experts revise the implausibility of the RCP 8.5 worst-case scenario, projecting about 3.5 C end-of-century warming.
5/18/2026 • Climate Science & Impacts • General
The Trump administration proposed changes to the Fifth National Climate Assessment in the United States that would remove high-end scenarios used to evaluate severe climate risks.
9/4/2026 • Policy, Politics & Governance • General
Systematic review of IPCC AR6 1.5C mitigation scenarios finds missing power-to-x modeling and overestimated bioenergy and fossil CCS contributions.
6/18/2026 • Clean Energy & Emissions • General
An April review retired high-emissions baseline scenarios used in climate modeling, with implications for central-bank stress tests and regulation grounded in scenario projections.
6/30/2026 • Policy, Politics & Governance • General
Climate scenario updates remove RCP8.5 and SSP5-8.5, citing emissions drivers and modeling improvements that change projected warming ranges.
5/27/2026 • Climate Science & Impacts • General
Late April IPCC statements labeling RCP8.5 implausible are discussed alongside claims that long use shaped energy policies, regulations, and public messaging.
7/21/2026 • Climate Science & Impacts • General
International climate modeling updates retire RCP8.5 and SSP5-8.5, while projections warn that 1.5 C warming is increasingly difficult.
6/9/2026 • Climate Science & Impacts • General
Climate scientists revise projected warming ranges in a report, concluding that dangerous impacts remain likely even with carbon removal potential.
5/22/2026 • Climate Science & Impacts • General
A UN climate assessment process is considering retiring RCP 8.5 because scientists now view the highest-emissions worst-case pathway as implausible.
5/19/2026 • Climate Science & Impacts • General
International climate researchers updated high emissions scenarios, replacing RCP8.5 with a less severe pathway projecting about 3.5C warming by 2100.
6/1/2026 • Climate Science & Impacts • General
Interesting
IPCC RCP8.5 worst-case warming impacts are described as increasingly unlikely as decarbonization progresses, despite delayed mitigation.
6/15/2026 • Climate Science & Impacts • General
Genevieve Guenther and Michael E. Mann argue in 2026 that President Donald Trump misrepresents updated emissions scenarios that still project severe climate risks.
5/22/2026 • Policy, Politics & Governance • General
FactCheck.org reported May 16 that Detlef van Vuuren and other climate researchers say new emissions scenarios are what-if tests, not retractions of climate science.
6/4/2026 • Policy, Politics & Governance • General
Donald Trump and right-wing media amplified the IPCC's move away from RCP8.5 and SSP5-8.5 as evidence against climate policy despite unchanged emphasis on rising climate risk.
6/2/2026 • Policy, Politics & Governance • General
Jason Bordoff and Noah Kaufman argue revised climate damages and worst-case scenarios do not lessen mitigation urgency, citing Europe heat risks and US regulatory rollbacks.
6/30/2026 • Economy, Business & Innovation • General
Climate scientists updated the SSP5-8.5 worst-case emissions scenario in May, shifting the extreme warming assumption to about 3.5C by 2100 as evidence and policy trends changed.
6/10/2026 • Policy, Politics & Governance • General
Climate scientists updated global warming scenarios in response to renewable cost declines, newer emissions trends, and policy changes, while high-end futures remain possible.
6/10/2026 • Policy, Politics & Governance • General
Quico Toro argues that RCP8.5 has been misused in climate debate and that local extreme risks persist despite the scenario’s reduced plausibility.
5/14/2026 • Policy, Politics & Governance • General
Donald Trump challenged IPCC-linked climate projection accuracy in a Truth Social post, amid disputes over EPA endangerment repeal arguments in the USA.
5/18/2026 • Policy, Politics & Governance • General
Additional
ScenarioMIP published an April 2026 paper concluding SSP5-8.5 high-end CMIP6 outcomes are implausible, challenging IPCC scenario-based policy and finance assumptions.
6/3/2026 • Policy, Politics & Governance • General