While the world has made progress bending the emissions curve away from worst-case outcomes where coal dominates our energy future, we are still far from the "safe bottom end". Current policies still risk a 4C+ warming world if sensitivity or carbon cycle feedbacks are high. 1/5

The world needs to dramatically reduce emissions – not just flatten them as we are on track to do today – if we want to have any chance to meet the Paris Agreement goals of limiting warming to 2C or below. 2/5

Right now we are on track for a best-estimate of 3C warming given current policies and energy system trends. But the same emissions scenario could lead to anywhere from 1.9C to 4.7C warming given uncertainties in Earth system response https://thebreakthrough.org/issues/energy/3c-world 3/5

The large uncertainties in the magnitude of the climate's response to our emissions suggests that we should be aggressive in reducing emissions – which are the one source of uncertainty in future warming that we have control over. 4/5

For more on uncertainties in climate sensitivity, see this article: https://www.carbonbrief.org/explainer-how-scientists-estimate-climate-sensitivity

For carbon cycle feedback uncertainties, see: https://www.carbonbrief.org/analysis-how-carbon-cycle-feedbacks-could-make-global-warming-worse 5/5