@ig747,
You went to Godwin's Law on this?
Look, air travel consumes fuel, yes. As does automobile traffic. And when your jet carries (for sake of an easy number) 100 people, it has the potential to take 100 cars off the road for the duration of the trip. This doesn't just save the pollution from those 100 cars. It may very well save more, because by alleviating traffic congestion and stop and go, cars will use less gas (stop and go takes more per gallon, and idling with the engine on burns fuel).
Because air travel is also safer, and fewer cars would be on the road, you can logically assume there could be fewer traffic accidents. Traffic accidents mean not just the accident, but also stopped traffic, possibly police, fire, and ambulances rushing to the scene (and burning fuel), possible fuel leaks or fires (also polluting), and possible totaled cars meaning a different car must be purchased. If a newer replacement car is bought, it's more likely to have better fuel efficiency. But buying used means the gas mileage might be worse.
Yes, when air disasters happen, they're horrible. There's no denying that. And yes, they use fuel, which can end up in groundwater, oceans, the soil, etc if there are leaks. Fires of course can pollute as well. Fortunately, the number of air disasters is low.
The average number of car accidents in the US every year is 6 million.
https://www.driverknowledge.com/car-accident-statistics/
Odds of being on an airline flight with at least 1 fatality: one in 3.4 million.
http://www.planecrashinfo.com/cause.htm
There were 19 plane incidents with at least 1 fatality in 2016, with 325 victims:
https://aviation-safety.net/graphics/infographics/ASN_infographic_2016.jpg
There is a lot more that goes into fuel calculations than just what goes into a plane. It's also saved fuel from automotive travel, savings from prevented accidents and the easing of traffic congestion.
And preventing pollution, while important, isn't the only measure of creating a better life for yourself and others. Preventing fatalities should be up there, too.