Yes, exactly. That's why we have these things called "flues", and "vent hoods".
So what's their point anyway? Probably something like "buy a total electric house and opt for a higher billing rate so you can say your house is powered by the windmills?"
Seems to be where they would be going with such stuff.
I have an eight burner, dual oven gas range and I love it. The vent can lift a small child and it sounds like an aircraft engine. Needless to say, Im not too concerned about this.
My electric appliances were about the same cost as gas to run, and was completely environmentally friendly and carbon free
Of course my electricity came from the local nuclear plant...