I've taken I think six flights in the past decade, all of which were between Great Britian and either Ireland or Continental Europe. Even these concern me if I am totally honest, but land or sea routes simply weren't available at the times I needed to travel. The prices for all of the flights were very low, far lower than travel by High Speed Train ever are. I do think it is important now in the short term to target flights between two airports in Great Britian and try to work towards ending a need for these permanently. It is obviously not a national priority for this to happen, though, and the government refuses to consider spending the money necessary to make that happen.
I don't feel guilty about it because someone in the guardian said I should, I was concerned about the equivalent atmospheric carbon they generated compared to my many long-distance train journeys anyway. I once travelled from Berlin Hbf to Mauldeth Road entirely by electric train in one day, which I was quite impressed with (I would want to ensure it were in 1st class if I were to do it again however, as it took literally the entire day, the bill for which would probably minimum £200 ish, as much as 10 times the price of the short 2 hour flight). I was completely 'flight-free' in 2015, 2016, 2017 and 2018, and didn't need to be told to part of a movement like this to do that. I do however appreciate the positive radical intentions that people have here. I think it's the sort of thing the world needs a bit more of, but it needs to be taken seriously at the highest levels of government that air travel is deeply unsustainable, before us making any personal choices will really have the necessary effect.
Similarly, I don't drive and have no plans to get my own car. I will however use a taxi on occasion, although I try very hard to avoid being the sole taxi passenger. I will also share people's car journeys if I can, or accept lifts offered. This is in contrast to someone I know who will literally refuse to travel by private car or taxi. If a bus service is unavailable, and they cannot cycle, they will just refuse to attend the event!