CMIP7 Scenarios Narrow Climate Pathways
New CMIP7 climate scenarios project a narrower warming range of 1.6C to 3.3C by 2100. They assume some overshoot of the 1.5C Paris target is unavoidable.
A new generation of seven emissions scenarios has been published to drive the seventh phase of the Coupled Model Intercomparison Project (CMIP7). These pathways, which will form a key evidence base for the Intergovernmental Panel on Climate Change's (IPCC) seventh assessment report (AR7), replace the shared socioeconomic pathways (SSPs) used in the previous cycle. According to an analysis by Carbon Brief, they depict a world where the highest plausible future emissions have been revised sharply downward. You can explore the underlying data and stats behind these projections.
The scenarios were detailed in a journal article in April 2026, with the underlying data released publicly on 1 September. Initial model runs using them began in spring 2026.
A Shift in Scenario Design
The new scenarios mark several departures from their predecessors. They are named simply for their emissions trajectories rather than by radiative forcing levels. They also no longer include 'no-climate-policy' baseline worlds. Instead, they explore futures where current policies continue, are strengthened, or weaken. The high-end emissions outlook has been dramatically lowered, reflecting a view that a coal-dominated 21st century is no longer plausible. Concurrently, the lowest scenarios have been revised upward, making some overshoot of the Paris Agreement's aspirational 1.5C limit now 'unavoidable,' Carbon Brief reports.
Socioeconomic Revisions
The scenarios are built on updated versions of the original SSP storylines, which incorporate revised assumptions about population and economic growth. These updates, finalized in 2024, paint a picture of a more crowded and slightly less wealthy planet per person than previously projected.
Global population projections were revised upward in nearly every scenario. In the updated middle-of-the-road SSP2, the population in 2100 is now 9.9 billion, one billion higher than in the original SSP. Economic projections (GDP) were revised downward for high-growth storylines and slightly upward for others. The combined effect is that income per person in 2100 is between 10% and 25% lower in most scenarios.
Emissions and Warming Outcomes
The seven CMIP7 scenarios yield a markedly narrower range of projected global warming by 2100 compared to the SSPs used in the IPCC's sixth assessment report (AR6). This new range will be crucial for understanding future climate standings.
| Scenario Name | Projected Warming in 2100 (vs Pre-Industrial) | Key Notes |
|---|---|---|
| Very-Low | ~1.6C | Peaks around 1.8C mid-century before declining. |
| Low-to-Negative | Not specified in source | |
| Medium | 2.9C | Analogous to current policies; crosses 2C around 2050. |
| High | 3.3C | Has around half the cumulative CO2 emissions of prior high scenarios. |
Carbon Brief's analysis indicates the overall warming range is 1.6C to 3.3C. This is a narrower band than the 1.5C to 4.7C range produced by the SSPs. For the first time in four generations of climate modeling, the top of the scenario range has fallen. Previous high scenarios resulted in approximately 4.6C to 4.9C of warming by 2100.
The new medium scenario, which reflects today's policy landscape, is projected to cross the 2C threshold around 2050 and reach 3C around 2110. It carries a one-in-four chance of exceeding 4C by 2150.
The Role of Carbon Dioxide Removal
Every scenario that limits warming relies heavily on carbon dioxide removal (CDR). The scale of assumed removal varies significantly across the pathways. By the year 2150, cumulative carbon dioxide removal ranges from 655 gigatonnes of CO2 in the very-low scenario to 2,360 gigatonnes in the low-to-negative scenario.
The development of these scenarios was coordinated by the Scenario Model Intercomparison Project (ScenarioMIP). The full Earth-system model simulations for CMIP7 are now underway, with initial results expected later this year.
