The 2% number is from the IPCC, and carbon emissions from planes have the same climate impact as carbon emissions from any other source (according to the IPCC). But just for the sake of argument, let’s say the number is much higher than that. Let’s say it was 10%, 5x higher than the IPCC claims it is. It still poses a negligible impact to the climate, and has the least ROI or any of the major contributors to carbon emissions. Electricity consumption is by far the biggest contributor, and is by far the easiest to solve. If we were to solve those problems, there’d be no need to even worry about aviation at all. This idea that all carbon emissions are terrible and must be eliminated is entirely counter productive, and entirely impossible.

A special characteristic of aircraft emissions is that most of them are produced at cruising altitudes high in the atmosphere. Scientific studies have shown that these high-altitude emissions have a more harmful climate impact because they trigger a series of chemical reactions and atmospheric effects that have a net warming effect.

This is what the IPCC is referring to when they say the climate impact is two to four times greater than from emissions alone.

This idea that all carbon emissions are terrible and must be eliminated is entirely counter productive, and entirely impossible.

We have left it too late, our only choice now is to do everything we can. There is plenty of air travel which is of marginal economic benefit that we can drop.