Not only CO2 but also Methan. It is 84 times more harmful in the first 20 years. But it is degrading on its own with a half-live of 7-12 years in the atmosphere. Methan makes up 20 to 30% of the human made GHG. Change to a plant based diet can reduce the emissions by 40%.

It is one of the few things we can change on our own very fast and does not need additional technological solutions to have a big impact.