Separate from the details of the consequences of global warming itself, more generally my hypothesis is that in order for a civilization to become aware that it is consuming too many natural resources requires a level of advanced development that can only be achieved by consuming too many resources. In other words, it might be more likely than not that when a planet produces a civilization that enters an industrial revolution it ends up burning through its natural resources in an unsustainable way and ends up collapsing. The easy access to resource surpluses that ignites the industrial revolution is also what causes them to overshoot their planet's capacity.

For us it's not just CO2 pollution that is a problem, there are many other resources that we are over-utilizing in an unsustainable way. And it seems that we are completely incapable of coordinating as a planet when the sacrifices are large. The hope of the techno-optimists is that technology will save us. It's a high-stakes bet that technology will figure it out before it's too late. Maybe the Great Filter is that when this bet is made across the universe the odds are generally in favor of losing.