I am sorry to say, the Earth is not a static place, but a living breathing system that changes constantly.
Difference is that now we have tremendous record keeping.
It sucked when algae came and polluted the atmosphere with waste oxygen back in the Precambrian. Probably sucked at the end of the Cretaceous when a couple of asteroids and a few mega volcanoes killed everything off. A few thousand years ago the planet went into deep freeze mode that killed a bunch of stuff off, as did the resulting meltdown. Some of those species were around, like the Mammoth, as late as 5000 years ago. Go figure. Maybe the Earth is warming up. Last time I checked, humans are part of the environment, not living in the environment.
I think economics will play a big role in the problems reflected here. As an American, there is little I can do to control other countries pollution policies short of going to war. I think people wanting clean air for the purpose of having less asthma and more sunshine will prompt people to make laws hear, and when other countries get to that point when their people give a crap about the water they drink and the air they breath, they will make those same laws, or die. If there are catastrophes from an increase in world temperature, then the population will simply go down or adapt.
IMHO people shouldn't have been living in NO to begin with. A city, surrounded by a huge volatile river, in a hurricane zone, that is below sea-level and sinking... Hmm, what is wrong with that statement. They only had like 3 warnings with incidents like the 1993 floods, and countless close call hurricanes... not to mention the wiping of Galveston off the face of the planet not 100 years ago...
I am for saving those people that were there. But I am against rebuilding it with taxpayer money...
Rant over, for now.