From a holistic #riskmanagement perspective, climate change is not the most imminent existential risk we are facing. Environmental degradation can indeed boil the frog alive. But said frog has no compunction to summarily kill itself, or at least "self-bomb itself to the Stone Age where it belongs".
Unless we develop conflict resolution methods that *manifestly* pacify quarrelling populations and unless we *effectively* ban ever more lethal technologies, the writing is on the wall: the 21st century will see massive, unprecedented loss of human life. Sustainability is not compatible with idiocy.