I'm not sure about other countries, but my understanding is that Canada is "honoring our commitments" to the Paris Climate Agreement in a way similar to how NATO members are honoring (or not, as the case may be) their financial commitments to NATO.
https://insideclimatenews.org/news/28032017/justin-trudeau-c...
But I suppose "that's different", right?
If the motivating factor behind stopping climate change is saving lives, how come no one ever gets morally outraged at non-American countries not keeping their word when it comes to military funding, which I think could be argued saves lives as well? (Although to be fair, the net number of lives saved by military funding is debatable.)