Mini Explainer Series Episode 5

October 10, 2022

CO2-equivalent explained

In this Episode

In 2021, 40 billion tonnes of manmade CO2 were released globally. But global greenhouse gas emissions for that year are described as 55 billion tonnes in CO2-equivalent (or CO2e). What’s the difference?

CO2 represents around 75% of greenhouse gases emitted by human activities, by weight. But by warming potential, it is much less. Other greenhouse gases (primarily methane, nitrous oxides and fluorinated gases) have much stronger warming effects in the atmosphere, and also remain in the atmosphere for vastly different periods of time. So how can we compare the warming impact of different emissions? By using CO2e.