What Word is Not Understandable?

What part of “Climate change is a rapidly worsening existential threat to humanity. Global temperature could reach an irreversible tipping point in just 12 years that will ensure our planet is uninhabitable.” causes people to NOT immediately sacrifice EVERYTHING for their children (borders, economies, inefficient houses, carbon-based economies, eating cows, etc.)? Is it the word “rapidly”, “worsening”, “existential” (look it up), “threat”, “irreversible”, “tipping”, “ensure”, “uninhabitable”... just what is the problem? What is more important than ensuring our planet can sustain us?