They probably know that visible effects of global warming won't manifest themselves until a century later: enough time for them and their kids. They don't care about their hypothetical grandkids. When the world starts collapsing in a century, they expect to have machines to fully replace 99% of the workforce: so most of the populace will fight for scare sources of clean water, while the rich would live somewhere in new Zealand, protected by unapproachable army of machines. That's what I think is their plan. However, I also think it's a naive plan.

Because wealthier people can always move. They can move away from flooded areas, away from hot ones. They can afford air conditioning, they will always be able to afford food and water, and they won't be called upon to serve in the military if there is a resource or land focused conflict.

Cooking the earth due to global warming might cause civilization to collapse, but not for 50 years; causing massive economic hardship by shutting down the fossil fuel infrastructure will end with the ruling class getting the guillotine tomorrow. For them, it’s no choice at all.