Differences between carbon budget estimates unravelled

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.