It’s because of the prisoner’s dilemma. It is broadly agreed that everyone would be better off if everyone curbs their emissions, but for any one individual the choice is not so simple. For infividuals, a large reduction to their impact will likely hurt them economically more than it will help them environmentally. This is exactly why a lot of green legislation is driven by global agreements with countries all trying to put pressure on each other to reduce emissions.

Likewise, increasing government investment in green technologies could benefit the economy and the environment, but for any given politician the cost of turning against big oil may be a significant risk to their chances of re-election if not balanced out by a politically motivated and educated populace that is resistant to corporate propaganda. Campaign finance reform would help with this, but once again it’s a bigger risk than it’s worth to the politicians in power. Thus, we can’t simply rely on the self-interest of the wealthy to prevent collapse; we must co-operate and coordinate our efforts to solve the problem.