[Amoeba]

I think what Digit means is that usually where heat is produced, CO2 is also produced and there are very few instances where CO2 is not produced from a heat source.

When our bodies generate heat, it's from our body's metabolic activity and respiration which produces CO2 as a waste product.

When we light a fire the carbon in the fuel reacts with the oxygen in the air triggered by an initial heat source (spark, friction, etc) resulting in the two reactants to combine and form the product CO2.

When our cars run and produce heat one of the waste products to come out of the exhaust pipe is CO2.

However, taking CO2 out of the atmosphere doesn't always produce heat, so it is possible to produce heat and still be able to lower the CO2 levels in the atmosphere (for example, plants produce a negligible amount of heat and can still absorb a lot of CO2). I don't think this is the way to go though, the issue should still be addressed at the source of the CO2 production.