They are roughly equal problems at the moment.

> Recent estimates show that contrails cause about the same amount of warming each year as all the CO₂ emitted by all flights from 1940 to 2018.

If we're measuring in terms of difficulty, CO2 is a much bigger problem than contrails.

Yes, contrails appears to be mostly solvable at a small cost in time and fuel and people have started to take action on that.

For most flights today though, if you only count the CO2 produced you're understanding the climate damage by about half.

	▲	hackernud3s an hour ago \| parent [-]
		It's one way to look at it I guess. CO2 is still the half of the damage that's way harder to fix.