Isn't this a drop in the ocean? Why would any 'normal' person forgo flying? How much CO2 emissions have 'world leaders' produced going to summits, or Taylor Swift and her fans flaying to concerts or war flights?
Couple of things: 1) NO ONE is suggesting any one forego flying altogether, or skipping their once-a-year overseas vacation or periodic family visit. 2) THIS level of flying is not normal and is exactly the kind of harmful behavior people have in mind when they complain about frequent flyers. 3) Whinging about summits and Taylor Swift is just a bad faith red herring argument. Obviously less flying is better, no matter by who. To the extent it's related to the topic at all, it bolsters the case for less air travel.
For this particular person, the inordinate factor is not the frequency of flights, but the distance: 40 flights in 2019, mostly from the US to Austria via Frankfurt. Now, there are some jobs that really do require such travel (though the business should probably consider hiring locally even though it might be more expensive?), but probably fairly few. The individual doesn't show flying stats after 2021, but presumably the work did get done even in the pandemic years when they couldn't fly as often.
I don't know why someone going on a vacation would have moral high ground over someone that HAS TO travel for his work. If you are scientist you absolutely have to fly a lot to visit lots of conferences, disseminate your work, provide lectures etc.
Understand this is both an individual and systemic critique. We have the internet. Much of the travel you describe can and should be done remotely. The top 1% of flyers account for 50% of emissions. I would argue most of that probably is unnecessary technically, but there is both a push and pull factor from people expecting some things to take place face to face.
We're adults, we can keep many things in our minds at one time: We should all reduce flying. Regular working people should not be shamed for taking a holiday and flying there. The most frequent fliers for work should make a personal effort to reduce their flying. And companies, conferences, etc. should work much harder to facilitate remote participation and reduce stigma around it, as well as encouraging other modes of travel. Governments should improve alternative solutions such as rail and high-speed rail.
Everything any one person does is a 'drop in the ocean'. Thankfully, we organize and do things collectively very well - it's in our fundamental nature going back to non-human ancestors, and there is a long, rich history of how much we accomplish. Alsmost nothing that has ever been accomplished has been done without a lot of people doing it together.
The general concern around Taylor Swift's emissions has always struck me as shortsighted. Her Eras tour is estimated to have generated around $5bn in economic uplift in the US, at an estimated 10,000 tonnes CO2e for her personal travel. Even if the total footprint is higher, that is thousands of times lower than the emissions intensity of an industry like fast fashion. From an environmental point of view, attending a Taylor Swift show is a much less carbon-intensive way to spend your money than ordering from Temu.