Climate change is not an existential threat

The long-term prognosis for human civilization is grim, but hopeful. The crises we will face do not generally pose an existential threat to human civilization on Earth. But it is undeniable that the risks of climate change, which include a range of unpredictable nonlinear effects, could radically and quickly change the face of the Earth and our ability to sustain our current civilization. Modern humans survived many rapid climatological upheavals in the millennia immediately leading up to the beginning of the Holocene. The Younger Dryas, Meltwater Pulses 1A and 1B, and the desertification of the once-green Sahara all changed the face of the Earth in ways observable in a single human life. And yet, human life went on.