> It will then become unacceptable to them that their efforts are in vain and at risk, because other countries are free riding and doing nothing, and continuing to pump emissions into the atmosphere.
The idea of invading countries to stop carbon emissions is interesting as a thought experiment, but given how things are now, it's far more likely that most countries (including rich countries) won't make efforts to massively reduce carbon emissions until it's far too late. It may already be far too late.
Most countries aren't even interested in trying to limit emissions to their current levels which is a complete joke compared to what is actually needed to have a chance of stopping global warming (assuming it can still be stopped).
Right now it seems like science fiction that anybody will try doing anything about the climate.
So, in reality we'll probably see a failing ecosystem and the strongest military killing the rest of us.
China needing to get rid of a couple million excess men is the thing that scares me most.
I could see China throwing a couple million men into a meat grinder with India. That could easily do enough damage to India to provoke a nuclear response.
What is stopping pre-brexit UK trying to nuke EU? The EU treaties?
(Probably not. But for the sake of argument.)
Der Krieg ist eine bloße Fortsetzung der Politik mit anderen Mitteln
War Is Merely the Continuation of Policy by Other Means"
Politicians always cause wars ... and always will. The only way we have a war over environment is when we impact a nation so they have no choice... or it has something to do with profit.
At some stage, a consensus must build for stopping our destruction of the climate. (Well perhaps it won't, but in that case we're doomed, so there's little point in evaluating that path).
At that point, some countries (presumably rich ones) will have cleaned their own houses emissions-wise and be signed up to assist poorer nations.
It will then become unacceptable to them that their efforts are in vain and at risk, because other countries are free riding and doing nothing, and continuing to pump emissions into the atmosphere.
Their mindset will move from pride at their own achievements to anger and frustration at others.
Soon after that will come enforcement. After all, it cannot be unreasonable to stop other countries from destroying the environment that we all share - even if those countries have to be destroyed to save the planet.