CMIP7 releases new emissions scenarios for climate modeling

A new set of emissions scenarios has been published for the seventh phase of the Coupled Model Intercomparison Project (CMIP7). These scenarios will serve as a primary evidence base for future projections in the Intergovernmental Panel on Climate Change (IPCC) seventh assessment cycle (AR7).

Replacing the previous “shared socioeconomic pathways” (SSPs), the CMIP7 scenarios are categorized by their emissions trajectories, ranging from “low-to-negative” to “high”. Unlike previous models, these do not include “no-climate-policy” baselines; instead, they analyze the impacts of current policies being strengthened, weakened, or maintained.

The new framework reflects a shift in global energy trends by revising high-end future emissions downward, as a coal-dominated 21st century is no longer considered plausible. Conversely, the lowest emissions scenarios have been revised upward, suggesting that exceeding the Paris Agreement’s 1.5C warming target is now “unavoidable”.