> A tradeable carbon rationing is indeed equivalent to a UBI
On the contrary -- I was saying it was not equivalent, because it also works towards the goal of reducing CO2 consumption, whereas I can't imagine how a UBI would do so.
> if the market is efficient then the consumption of CO2 credits will exactly equal production
The carbon credits I am imagining would not be "produced" per se -- they would, in total, represent the total amount of carbon we as a country want to emit, to reduce climate disaster, allocated equally to each individual, who all collectively "own" that natural limit. Those individuals can then sell their "contribution ration" to companies which wish to emit more than the CO2 allocated individually to their CEO, or whatever. So ideally credits will be available for purchase by the CEO, at whatever rate the CEO's fellow people are willing to charge the CEO. Mitigations will need to be done by humanity regardless, or else.
My point was, maybe it is a single number! It's whatever We The People decide, and it doesn't vary: a ton of CO2 released into the air does the same damage no matter what released it. You could spend it saving orphans, and it wouldn't make the CO2 heat the planet any less, and it wouldn't remove the need to find a new way to save orphans that doesn't emit CO2.
Indeed, examining the quote below...
> So you either get more CO2 released than you would with an externality tax or you get less CO2 released than you should given that you can mitigate against that particular CO2 release
...it's easy to miss the point that there's no such thing as "less CO2 released than you should" because the amount we should is negative: not only should we be emitting zero (not net zero, literally zero), and then we must do the mitigations on top of that.
In short, we've tried the existing carbon credit scheme without rationing the available credits, and it hasn't worked to achieve the goal. We need to try something different now.
No CO2 emissions is not the terminal value of the human race. It is a means, not an ends. The damage of that extra ton of CO2 is not infinite.
If releasing a marginal megaton of CO2 caused climate issues that cost a thousand lives over the next 200 years but we want to release that marginal megaton because it let's us save ten thousand orphans than we should release that CO2.
It might be that in the world we live in the correct CO2 per ton tax that takes into account externalities is literally greater than the price of capturing a ton of CO2, in which case all but niche cases (antique car drivers and space launchers probably) will stop producing CO2. But I don't know that and the estimates I've seen have a CO2 tax that pays for the climate externalities at less than a quarter of the price of atmospheric carbon capture (and thats the top end of CO2 tax estimates!).
On the contrary -- I was saying it was not equivalent, because it also works towards the goal of reducing CO2 consumption, whereas I can't imagine how a UBI would do so.
> if the market is efficient then the consumption of CO2 credits will exactly equal production
The carbon credits I am imagining would not be "produced" per se -- they would, in total, represent the total amount of carbon we as a country want to emit, to reduce climate disaster, allocated equally to each individual, who all collectively "own" that natural limit. Those individuals can then sell their "contribution ration" to companies which wish to emit more than the CO2 allocated individually to their CEO, or whatever. So ideally credits will be available for purchase by the CEO, at whatever rate the CEO's fellow people are willing to charge the CEO. Mitigations will need to be done by humanity regardless, or else.