# Airline CO2 emissions

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?

• Well, if you said "airline(r)", the 50K figure is way too much. It's too much even if you include small aircraft (which consume 1-2 orders of magnitude less). The usual estimate is 7-9 thousand aircraft in the air (for which 5 t/h is a reasonable order-of-magnitude average). So here you are ~order of magnitude off, and the rest is plausible (again within the order): worldwide industry produces ~10% of a country's emission. If you need an exact tally, I'm sure somebody already did it.
– Zeus
Commented Jul 25, 2023 at 2:51
• An idling aircraft uses far less fuel than one that's cruising, which in turn uses far less fuel than one that's taking off. You can't just say "an airplane uses x tons of fuel per hour".
– Mark
Commented Aug 3, 2023 at 1:55
• The linked article mentions how in 2021 the total of American greenhouse emissions was a little above 6 billion metric ("6,340.2 million") tons. Commented Sep 12, 2023 at 21:04