Current Remaining Carbon Budget

The Current Remaining Carbon Budget is the amount of CO₂ expressed in Gigatonnes that can be emitted in the future to keep human-induced warming below limits such as 1.5 °C (2.7 °F), 1.7 °C (3.06 °F), 2 °C (3.6 °F).

Likelihood

The Remaining Carbon Budget is not just a single number. Scientists calculate budgets for a range of ‘likelihoods’ and limits. You can inspect the likelihood and the corresponding budget by adjusting the likelihood slider in the widget. A higher likelihood of limiting warming (67%, 83%, or 90%) corresponds to a lower remaining carbon budget and a lower likelihood (10%, 17%, or 33%) to a higher budget.

Keep in mind that the Paris Agreement, a legally binding international treaty on climate change, sets an overarching goal to hold “the increase in the global average temperature to well below 2°C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C above pre-industrial levels.” To limit global warming to 1.5°C, greenhouse gas emissions must peak before 2025 at the latest and decline by 43% by 2030.

Exhaustion Rate and Estimated Year

The value “exhausted in” is an estimate of the year when the remaining carbon budget will be exhausted based on a chosen likelihood and on the latest given “exhaustion rate” of 40 Gt CO₂ per year.

Only for CO₂ Emissions

The remaining carbon budget is only for CO₂ emissions, and not to be confused with CO₂-equivalent (CO₂e) emissions. However, the budget calculations take into account that other human factors also influence the human-induced warming, for example methane CH₄, N₂O and sulfur dioxide. Unexpected changes in these factors also change the Remaining Carbon Budget, which is recalculated yearly by the IGCC.

Key Take-Aways

• The current 2025 budget for a likelihood of 50% to stay under 1.5 °C (2.7 °F) is 130 gigatonnes CO₂, with estimated exhaustion in 2028.
• The current 2025 budget for a likelihood of 83% to stay under 1.5 °C (2.7 °F) is 30 gigatonnes CO₂ and estimated to exhaust this year.
• With current CO₂ emissions (exhaustion rate), the budget will be exhausted within the next 10 years for all likelihoods. There could not be a clearer message that this decade is crucial for reducing carbon emissions.

About the Data

The data is produced by the Indicators of Global Climate Change (IGCC) initiative to spread indicators of climate change that are consistent with the IPCC Assessment Report 6. The IGCC produces estimates for key climate indicators: emissions of greenhouse gases and short-lived climate forcers, greenhouse gas concentrations, radiative forcing, surface temperature changes, the Earth’s energy imbalance, warming attributed to human activities, the remaining carbon budget, sea level rise, and estimates of global temperature extremes.

Units and measures

The Remaining Carbon Budget is expressed in gigatonnes of CO₂.

Data Sources

IGCC Indicators of Global Climate Change 2024: annual update of key indicators of the state of the climate system and human influence, Piers M. Forster et al.
Credits: Credits: Smith, C., Walsh, T., Gillett, N., Hall, B., Hauser, M., Krummel, P., Lamb, W., Lamboll, R., Lan, X., Muhle, J., Palmer, M., Ribes, A., Schumacher, D., Seneviratne, S., Trewin, B., von Schuckmann, K., & Forster, P. (2024). ClimateIndicator/data: Indicators of Global Climate Change 2023 revision (v2024.05.29a) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.8000192Update cycle: yearlyDelay: Up to a year