No, nobody is actually paying for CO2 emission externalities. At best, you can argue that maybe someone will be paying them some day in future, but it’s a big fat maybe. Because nobody is actually paying for these externalities, we don’t have any figures of how much those externalities cost — you can come up with some estimates, but as GOSPLAN experience shows, calculating prices outside of markets is a fool’s errand. Moreover, our best estimates of these costs is rather low, especially if you do time discounting. Planes would still be cheaper than trains even if they had to pay these. Finally, since most of electricity in Europe still comes from fossil fuels, emission externalities are just as much of a problem for them as they are for trains, especially if you consider that the GHG emissions per actual passenger kilometer between trains and planes are rather similar: trains tend to be really heavy, and usually run much more empty than planes.
People are already paying for those externalities in extreme weather events caused by CO2, also from carbon taxes in other countries that wouldn't have been necessary otherwise, from people who have to buy more expensive cars and fuel, etc...
> People are already paying for those externalities in extreme weather events caused by CO2,
And others are benefitting from positive externalities of warmer weather, reducing need for heating, increases yields due to increased CO2 concentration etc. Thing is, it’s incredibly hard to put a number on net costs on climate change. The most serious recent attempt to do that had its author, William Nordhaus, a Nobel Prize in Economics. The estimated figure, by the way, is very low compared to the zeal of the activists.
Now, of course, the carbon tax proponents are not really interested in the actual costs. They either ideologically hate emissions, and their desire to institute carbon tax is vindictive in its nature, and all talk about “externalities” is for them just a distraction, or they are politicians who use carbon tax as an excuse to increase their political power and tax revenues. Nobody is motivated by actual economic efficiency, and calling them Pigouvian taxes is a distraction.
Nordhaus's work is absolutely panned as being basically literally insane by actual scientists. He based a large parts of his analysis on ideas like "well x% (something like 75%+) of GDP happens indoors so that won't be affected by any way by climate change".
Why didn't those actual scientists bring this up when he, you know, got a Nobel Prize for that? Or are you arguing here that Nobel Prize is a joke, and people who give it are total idiots?
The 'Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel' isn't really much like the actual Nobel Prizes (except maybe the Nobel Peace Prize, that one has proven to be a bit of a joke too, but at least it's a real Nobel Prize).
Where I'm at, in the North, recent weather has only increased climate control costs due to colder winters and hotter summers. I can't say for sure it's global warming at work.
William's Nordhaus models for which he has received the Nobel prize predate the millennium, and have been superceded since then by much better models. His models are highly problematic, now that we know that you cannot extrapolate the average temperature on GDP due to increased amplitude, and for many other reasons. That is why the Nobel committee awarded it not for the current relevance of the results, but for the pioneering nature of the research.