When carbon dioxide is released, it has an impact on our climate.
There are other gases, like methane, that have significantly more impact, particularly in the short run.
Climate scientists often talk about these “greenhouse gas emissions” and, to make the impact easier to understand, use “CO2e.” C02e is a metric measure that describes the net effect of a mix of gases by converting their impact to the equivalent of CO2.
So a tonne of methane has, over 20 years, the impact of more than 80 tons of CO2, or 80+ CO2e.
CO2e can also be used to describe a mix of gases that include CO2.
In the year 2019, an estimated 37 gigatonnes (gt) of CO2 were released by human activity, with another 13 gt in CO2 type impact from other greenhouse gases.
So the annual CO2e was 50 gt.