Dropping worst-case climate scenario doesn’t reduce threat, scientists warn

Climate scientists are cautioning that the decision to drop the worst‑case warming scenario should not be misinterpreted as a reduction in the threat posed by global warming. According to French daily Le Monde, recent climate projections have abandoned the “RCP 8.5” pathway — which long symbolised a catastrophic future with nearly 5°C warming by 2100 — but this change reflects real‑world developments rather than an overstatement of climate risks.

New pathways and unavoidable warming

An April 7 study outlined seven new emissions pathways. The extreme scenario is no longer considered realistic, while the most optimistic pathways also appear increasingly unlikely. The study found that exceeding the 1.5°C threshold is now unavoidable, and the world is drifting further from the Paris Agreement’s most ambitious goal. Global warming is projected to reach about 3.5°C by 2100 — roughly 1°C lower than previous estimates. However, lead author Detlef van Vuuren warned that warming levels comparable to the old RCP 8.5 scenario could still be reached by 2150.

Devastating consequences remain

Climatologist Michael Mann warned that even 3.5°C warming by 2100 would have catastrophic global effects, pointing to current impacts — heatwaves, droughts, wildfires, floods — at a time when temperatures are already approaching the 1.5°C threshold. The revision is driven by falling renewable energy costs and the adoption of transition policies in many countries.