Carbon and emission budgets

To stabilise warming, CO2 emissions ultimately have to be reduced to zero. The faster this zero point is achieved, the lower the level at which warming stabilises. We explore the total cumulative emissions (budgets) consistent with long-term global climate goals, such as holding warming below 1.5 and 2°C warming relative to pre-industrial levels


This technical note looks at the estimates of the remaining warming that have been used in the IPCC AR5 and in recent studies, and evaluates the consequences for carbon budget estimates to limit warming to 1.5°C.  
Accepted estimates of how much carbon we can still burn by the end of this century and keep temperature rise to below 2°C range from 590 to 2390 billion tons of carbon dioxide. The high end of this estimate does not take into account warming by non-CO2 emissions and was never intended to be used to address a real-world policy question. Consequently, this study finds that the most appropriate carbon budget estimate for keeping warming to below 2°C is in the range of 590-1240 billion tons of carbon dioxide.