I don’t see the actual climate change as an existential threat to the human race in a way something like nuclear war, a pandemic, asteroid or AI could be. It’s bad but it’s not that bad.
Beyond that threshold, scientists have found, climate disasters will become so extreme that people will not be able to adapt. Basic components of the Earth system will be fundamentally, irrevocably altered.
The report reveals thresholds in how much warming people and ecosystems can adapt to. Some are “soft” limits — determined by shortcomings in political and social systems. For example, a low-income community that can’t afford to build flood controls faces soft limits to dealing with sea level rise.
But beyond 1.5 degrees of warming, the IPCC says, humanity will run up against “hard limits” to adaptation. Temperatures will get too high to grow many staple crops. Droughts will become so severe that even the strongest water conservation measures can’t compensate. In a world that has warmed roughly 3 degrees Celsius (5.4 degrees Fahrenheit) — where humanity appears to be headed — the harsh physical realities of climate change will be deadly for countless plants, animals and people