The tax that applies to every single business, every single product, every single process, everything. The one that causes every single vested interest to come out of the woodwork and join together to make it politically toxic.
We tried this in Australia. It has killed every government that even dared to discuss it. And politically it is utterly impossible to defend e.g. "Carbon tax that raises power prices for pensioners".
Our carbon tax worked at reducing emissions, and at being low economic impact. It was removed because we are a corrupt banana republic, not because it's unworkable.
"The Largest Public Statement of Economists in History": https://clcouncil.org/economists-statement/
For a while. But if the carbon tax works and society switches to clean energy, then there is no more emissions and no more dividends pay to the citizens.
Moreover, I think the same model can apply to other negative externalities (aka, Pigovian Tax [0]). But to the extent that the public will someday complain that their carbon dividend is going down: (a) I call that a good problem to have, and (b) because the collective action problem now points the other direction, there's no individual incentive to over-consume such that the dividend goes up again.
Two birds, one stone.
Opponents of carbon tax and similar measures need to decide which they like less... some lost profits, an escalating carbon tax, and reshuffling their investment portfolios -- or food riots, mass migration, the massive resurgence of left wing populism, and even civil war, once the effects of climate change become intense and obvious to the populace.
Not to mention the water supply of Calgary and many other western Canadian cities is glacier fed, and the Bow Glacier that provides to Calgary may not be able to meet demand within the next 30 years... a problem that will only get worse with climate change.
Yes, the great lakes region looks better than most. And it will look desirable to a lot of displaced people...
We need to think past that point: how will the world look like once civilization has collapsed? What will still exist? What will not?
IMHO, the first step is to migrate coal power plants to capture and storage. It is much easier to drop emissions than to pull from the air. I would like to see more tax pressure globally incentivizing carbon release reductions. Instead you get weird stuff like Japan's carbon tax where coal pays the lowest carbon tax of gasoline and diesel.
Then pull it out of political discussion! We don't have political discussion about "how to hang people of color Q better" anywhere in the world (mostly) anymore because we've wrote it in the text of our f laws that violence and racial discrimination are forbidden! Not on the political menu anymore.
Same needs to happen with lots of stuff concerning climate, ecology, sustainability etc. - we need to restrict the political menu to only the right choices.
And use the states' monopoly on violence to enforce these choices.
Yeah, sure, you can philosophise in the most general terms but that's not how you get people and companies stop doing wrong things. You get them when the people/entities who want to re-bring the despicable things back into discussion can be fined / closed / put-in-prison etc.
I don't argue for eco-fascism. But with some things we need to be ruthless, especially in order to be able to carry on our peaceful, understanding and democratic discussions concerning all the other things!