UN Climate Agency Removes Worst-Case Emissions Scenario

The United Nations Intergovernmental Panel on Climate Change (IPCC) has officially removed the RCP 8.5 worst-case emissions pathway from its future projections [1, 2].

This shift indicates a fundamental change in how scientists forecast the planet's temperature rise. By removing the most extreme scenario, the agency acknowledges that the most catastrophic outcomes previously feared are now less likely to occur.

The decision follows updated climate modelling that reflects the real-world impact of energy transitions. Scientists said that the increasing availability and falling costs of solar and wind power have lowered projected emissions [4, 5]. These technological shifts have effectively reduced the temperature rise forecast for the most aggressive emissions pathway.

Under the former worst-case scenario, projections suggested the world could see warming of about four °C by 2100 ^[6]. Some versions of that specific model even projected warming as high as five °C by the end of the century ^[6].

In the latest assessment, the worst-case projection has been cut by roughly one °C ^[3]. While the removal of the RCP 8.5 pathway suggests the world may not get as hot as previously feared, reports indicate that global temperatures will still likely exceed established warming limits ^[5].

The IPCC process relies on these scenarios to guide global policy and infrastructure planning. The removal of this extreme outlier suggests that the trajectory of global carbon emissions is shifting away from the most volatile predictions made in previous decades.