The failure of our times has been just this. Not realizing that when what you are doing has global impact you need to think hard about its effects and be crystal clear on the ethics of it all. Perhaps the original sin was not pushing for more hands-on ethics training for every child and college student.
The Kyoto Protocol was in 1997, but the US didn’t ratify it because the API managed to influence US politicians enough to cast doubt on the problem.
Granted, NZ's a small country, but if it was known about there pre Great War, I suspect many people knew about it elsewhere too.
It is one of those things that until very recently had been quite easy to ignore though I suppose (and many still try even now).