Carbon Budget
The total cumulative amount of carbon dioxide that can be emitted globally under a given temperature limit. It is tied to cumulative emissions rather than annual flows and serves as the arithmetic basis for climate policy and emissions accounting.
Timeline (last 90 days)
If positive feedbacks are underestimated, nationally determined contributions and net-zero timelines based on old carbon budgets may be too lenient.
Carbon budgets are derived directly from the warming response of climate models, which implicitly embeds assumptions about feedback strength.
The IPCC Sixth Assessment Report estimates that to keep warming within 1.5°C (with 50% probability), the remaining carbon budget is about 500 billion tonnes of CO₂.
The carbon budget is tied to cumulative emissions rather than the emissions flow of a given year; historical emissions have already locked in part of the warming, and even if future emissions dropped to zero, the warming that has already occurred would not reverse.
All Facts (4)
Carbon budgets are derived directly from the warming response of climate models, which implicitly embeds assumptions about feedback strength.
50%UnverifiedThe IPCC Sixth Assessment Report estimates that to keep warming within 1.5°C (with 50% probability), the remaining carbon budget is about 500 billion tonnes of CO₂.
50%UnverifiedThe carbon budget is tied to cumulative emissions rather than the emissions flow of a given year; historical emissions have already locked in part of the warming, and even if future emissions dropped to zero, the warming that has already occurred would not reverse.
50%UnverifiedIf positive feedbacks are underestimated, nationally determined contributions and net-zero timelines based on old carbon budgets may be too lenient.
50%