There are 50,000 aircraft in the air or idling all the time. An airliner consumes 5 tons (or whatever) per hour of fuel. So 3 billion tons per year of fuel. So one ton of fuel is actually 3 tons of CO2, so 10 billion total.
American CO2 emissions are 10 billion tons, according to this page. So how is it mathematically possible the airline industry produces more CO2 than the entire country combined?