Climate change projections for 2100
Pro Research Analysisby 
Searched over 200M research papers
Global Temperature Projections for 2100: Key Scenarios and Ranges
Climate change projections for 2100 show a range of possible global temperature increases, depending on greenhouse gas emissions, climate sensitivity, and policy actions. Most recent and widely accepted scenarios suggest that, without significant mitigation, global average temperatures are likely to rise between 2°C and 5°C above pre-industrial levels by 2100, with some models projecting even higher increases under certain assumptions 134567910.
Moderate Emissions Scenarios: 2°C to 3°C Warming
Several studies using plausible emissions scenarios and current mitigation trends project a global temperature increase of about 2°C to 3°C by 2100. These projections are based on observed emissions growth rates and assume continued, but not drastic, mitigation efforts. The median warming in these scenarios is around 2.2°C, but staying below 2°C is considered unlikely without much faster reductions in carbon intensity than have been seen in recent years 349. Probabilistic models also show that there is only a small chance (about 5%) of limiting warming to less than 2°C, and an even smaller chance (1%) of staying below 1.5°C .
High Emissions and Sensitivity: 4°C to 6°C or More
Some models and reviews, especially those considering high emissions and higher climate sensitivity, project much greater warming—up to 5°C or 6°C by 2100. These higher-end projections are based on scenarios with continued high fossil fuel use and limited mitigation, as well as models that are more sensitive to greenhouse gas concentrations 257. For example, one probabilistic forecast found a median warming of 5.1°C by 2100 under business-as-usual conditions . However, some of the most extreme emissions scenarios are now considered unlikely by many experts .
Lower Emissions Pathways: 1.5°C to 2°C Possible but Unlikely
The lowest emissions scenarios, such as those represented by RCP2.6, project warming of about 1.5°C by 2100, but these require immediate and aggressive global mitigation efforts, including net negative emissions later in the century . Most current trends and policies do not align with these pathways, making them difficult to achieve 346.
Regional and Local Variability in Warming
Warming will not be uniform across the globe. High latitudes, especially the Arctic, are expected to warm much more than the global average, with some projections showing a 5% chance of the Arctic warming by as much as 16°C by 2100. Continents are projected to warm more than oceans, and the Northern Hemisphere more than the Southern Hemisphere, except for the North Atlantic region .
Uncertainties in Climate Projections
Uncertainties in projections arise from several sources: future emissions scenarios, climate model differences, feedbacks in the carbon cycle, and natural variability. While short-term projections are more constrained, uncertainties grow over longer timescales, especially due to model and scenario differences . However, recent improvements in models and observational constraints have increased confidence in the overall range of projections .
Policy Implications and Adaptation
Most studies agree that current mitigation efforts are not sufficient to limit warming to below 2°C, and much faster declines in carbon intensity are needed to meet the Paris Agreement targets 34. Some analyses suggest that moderate adaptation and mitigation policies could manage many climate risks if warming stays near or below 2.5°C to 3°C, but more severe warming would pose much greater risks and require more drastic action .
Conclusion
By 2100, global average temperatures are projected to rise by 2°C to 3°C under current trends, with higher increases possible if emissions remain high and climate sensitivity is at the upper end of estimates. Achieving less than 2°C warming is unlikely without rapid and sustained global mitigation. Regional differences will be significant, with the Arctic and continental regions experiencing the most warming. Uncertainties remain, but the overall direction and risks of continued warming are clear.
Sources and full results
Most relevant research papers on this topic