Existential threat by definition is a threat to people's or humanity’s existence or survival. It comes from the Latin root existentia meaning survival. Reshapi

Existential threat by definition is a threat to people's or humanity’s existence or survival. It comes from the Latin root existentia meaning survival. Reshaping coastlines and raising temperatures probably won’t kill off humanity. But it will change virtually every aspect of our society and potentially kill of technological civilization as you say. Therefore it’s more than an existential threat of destroying humanity. I meant it how it’s meant to use used: the range of possibilities major sea level rise far exceeds the risk of extinction or the end of humanity, it possesses a range of possible outcomes that would reshape society itself and change inconceivable numbers of things beyond the possibility of merely wiping out the species. I hear the Islands of California can be quite lovely in the spring, and the Florida banks have excellent fishing if you don’t mind the super hurricanes.