Perhaps that's how it should be in a perfect world, but in the world we live in that isn't the case and doesn't seem likely to be the case - there are some local markets for CO2 incentives, but on the international level there's no willingness for major emitter countries to pay other countries, no evidence that (or why) this willingness might appear, and there's no global government that could make or enforce any rules unless countries opt-in; nobody can force nuclear countries to pay others.
> but on the international level there's no willingness for major emitter countries to pay other countries, no evidence that (or why) this willingness might appear
Of course no one wants to pay, but courts have already begun shifting their attitude in a number of historic rulings against large emitters, and there are a ton of cases being in progress at the moment [1]. IMHO it's only a matter of time until the first court orders direct international financial damage payments, particularly to countries that threaten to be literally flooded from the map like Vanuatu [2]. For what it's worth, most Western countries already pay large sums of money to the Global South as part of general development aid.
> and there's no global government that could make or enforce any rules unless countries opt-in
The US absolutely can, like they did with anti money-laundering legislation. Everything and everyone that touches the US dollar is, in the end, accountable to the US and its will.
Besides, who would have thought that the world would eventually converge on getting rid of tax havens? To force the Swiss of all people to dismantle the holy grail of bank secrecy? Almost no one, given the absurd amounts of money at stake, and yet it happened (partially though as a consequence of the various leaks of tax evader data).
I understand your position, however, I feel there's lots of wishful thinking there. The key issue is whether the industrialized first world countries would be forced to compensate the 'global south' for the damage of the global warming beyond anything they willingly choose to donate as part of their foreign aid budgets, and for that I strongly believe the answer is negative.
Of the examples you provide, there are a ton of cases but not a lot of judgments, and furthermore these cases are overwhelmingly against specific companies and many of them for violating obligations they have under USA law. USA permits that as long as they feel that it matches their interests (e.g. having British Petroleum pay a compensation to some USA city is a good thing) and it can and will alter the laws of this liability if they start threatening USA interests.
The Vanuatu example you state is (a) explicitly not asking for any financial damages[1], (b) the only thing that was agreed was to forward it to the ICJ; and (c) the decisions of ICJ are not binding, and USA has an explicit policy since 1986 to choose on a per-case basis whether they'll want to consider themselves under ICJ jurisdiction for that case or not, and so do other countries.
W.r.t the lack of global government - yes, you provide examples of how diplomatic and trade pressure from powerful countries can push smaller ones to concede. That doesn't work in the opposite direction - the same mechanisms can't force USA (or China) to change their policies or fund global change.
Fundamentally, USA (just as any sovereign country) doesn't legally owe Vanuatu anything beyond those obligations that they willingly take on, international law is simply about controlling adherence to a set of voluntary contracts between countries. And even for the existing conventions, international law is clear that countries can abandon them when they don't like the obligations, and that has happened many times in the past - so I'll repeat my point that any compensations will happen only if (and to the extent of) that the western governments opt-in, and as the consequences of the climate crisis increases, their willingness to do so will be even more limited by the needs of their own voters.
[1] Quoting the same washingtonpost article, "As Vanuatu gained support for the U.N. action, it was careful to try to build consensus, with its leaders saying they are not suing anyone nor seeking to create new international obligations. Instead, they say, they are seeking to clarify how preexisting international agreements apply to climate change."
