They sure do if they have to be lugged up to the 45th floor in some skysraper every morning.
Strictly from a biological standpoint, fat is a depot form of energy storage and isn't as metabolically active as muscle. Obese people tend to more sedentary and will therefore expend fewer movement related calories...one the other hand...they eat more and it takes energy to produce food. The key is probably "lean body mass". People with larger lean body mass will produce more CO2 per day than a smaller individual, all things being equal.
I realize your question wasn't like meant to be literal