Overview
- Scientists have removed RCP8.5, a coal‑heavy worst‑case pathway created in 2011, from the set of plausible futures and introduced seven updated scenarios.
- The new high end points to about 3.5°C of warming by 2100, while even the most optimistic case still overshoots the Paris goal of 1.5°C.
- Researchers cite steep declines in wind and solar costs, recent emissions trends, and emerging climate rules as reasons the old extreme is now implausible.
- Experts stress that major hazards remain, noting current warming near 1.3°C and warning that natural feedbacks like carbon release from oceans and forests could add roughly 0.5°C.
- The revision is fueling political fights, with President Trump celebrating and AP calling his post misleading, while analysts such as Roger Pielke Jr. urge a fresh review of studies and regulations that relied on RCP8.5.