Environmental politics, the academy, and air travel

I have a colleague who has been putting a lot of time and effort into getting the University of Colorado to adopt some policies to help incentivize employees, especially members of the faculty, cut back on work-related air travel. The numbers he quotes on this issue are very startling. Basically somebody who flies from the middle of the country (that’s where Colorado is; not a lot of people know that) to the East Coast and back once is using about a fifth of the average American’s total carbon emissions for a year, while the average American is using ten times as much as the average Indian, so if somebody is flying to a half dozen conferences and the like a year, well . . .
My understanding is that he’s run into a whole lot of resistance/unhappiness from the central administration in regard to these efforts, for what reasons I don’t know but can easily guess.
Recently during my transmogrification into Elbow Guy I back of the enveloped that I’ve probably averaged five roundtrip plane flights a year over the past 15 years or so, with maybe half of those being work-related and the rest personal, mainly to visit my family in Michigan (I’ve lived there all my life, I’ve been their guest). This figure might get bumped down closer to four or so by the fact that I didn’t take a single flight for the two peak years of the pandemic, but it’s still disturbingly high, given my colleague’s figures.
Which brings up the uncomfortable topic of how much air travel is justifiable under present circumstances, especially if you’re not a climate change-denying right wing nut case, like the very soon to be president again of the United States and the rest of his party of unhinged superstitious authoritarians.
Greta Thunberg takes sailboats across the Atlantic, which isn’t a realistic option for even the most dedicated of bougie knowledge class workers, but on the other hand I’m pretty sure the correct answer to this question isn’t to intone that “there is no ethical consumption under capitalism,” before booking yet another trip to the annual conference of law professors in San Francisco (Theme: “Courage in Action”) at one’s employer’s expense, to “go to some panels” (and some fabulous restaurants!).