The Trillionth Tonne of Carbon and Why It Matters For Climate Change

When we connect our model of the global carbon cycle to the model of atmosphere-ocean temperatures we find every tonne of CO2 we dump into the atmosphere ratchets up global temperatures, permanently, by around half a trillionth of a degree Celsius. So, to stop global warming, we need net zero carbon dioxide emissions. And to limit warming to 2°C, we need to limit the total amount we emit to around 3.7 trillion tonnes of CO2: one trillion tonnes of carbon. A lecture by Myles Allen recor...