We've created a society that encourages and in many cases necessitates short term thinking. If you could buy shares in 'Saving the planet' and they gave the best return, we'd be breeding insects in every small nook and cranny available. As it is environmental protections are only considered if the act of not giving a shit will impact the ability to make money. Of course if we kill the planet no-one will make any money, but why would someone trying to make a million today care about not being able to make a million 100, 200 or 500 years from now? Some will, the very vast majority won't. It's too abstract an idea. Too easy to kick the can down the road. It will take an immediate and very large catastrophe to change the current system.
It's also something that everyone has to work towards. It's no good just saying politicians or the wealthy should do something. It's true that they're in positions of greater power and influence and thus shoulder greater responsibility, but being truthful about what the planet can support will hit the lifestyle of every person in every home, certainly in the developed world. And we need to be prepared when those politicians or wealthy turn around and say "We can fix it, but you all have to stop doing X and consuming Y".