I don't believe climate change will be the downfall of human civilization, but it's not just an alarmist take. There's actual reason to believe it could be. The

I don't believe climate change will be the downfall of human civilization, but it's not just an alarmist take. There's actual reason to believe it could be. The problem is that it's a potentially self-accelerating problem, like a nuclear meltdown. As the planet warms, more CO2 that is locked up in melting glaciers will be released, accelerating the problem. Rising sea levels could displace a significant portion of humanity, causing a level of unrest and chaos that could make it hard to muster the governmental and intergovernmental efforts that might be require to slow or stop the problem. Food scarcity could further these issues. People won't be worrying about investing in green energy if they're worrying about whether they or their neighbor will be the one who gets the last bag of rice. And my biggest concern: CO2 makes us stupider. As ambient CO2 levels rise, people can't think as clearly -- we're talking about the entire collective intelligence of the human race potentially being reduced significantly if CO2 levels rise to not that much higher than they are now. The effect is noticeable at 1000 ppm, and indoor concentrations can be 2x to 3x outdoor concentrations. Right now we're at 424 atmospheric ppm. It's not hard to imagine that worst-case increases could literally smother the brains of every human on the planet. And then civilization is literally at risk. Again: I don't ascribe much weight into the probability of that worst case. I put a lot of stock into the incredible ingenuity of humans to solve problems, once they actually acknowledge that they are problems. So I'm pretty sure we'll get through this as a species (although some coastal cities may not, at least in their current form). But the end of civilization is not merely alarmist -- it's an actual worst-case possibility that we should be aware of.