Depends where you take the train to London, it is a much nicer experience anyhow than going to airports and people should consider that as well (ignoring climate stuff)!

On the price, the very annoying thing is that fuel for planes is not taxed! Changing this would require quite some effort (falls under some specific laws, that are old and nobody wants to touch, etc.) but I think everybody should just ask "honest tax on fuels!" as this will make less people say (or thin) "but climate change is a hoax". Planes are just unfair competition to other transport due to taxes!

I agree re: fuel taxes, but it’s a complete nonstarter: passengers would be voting against their wallets, and airlines would lobby against it since it’s a vote against their business model.