The 9 Boundaries Humanity Must Respect to Keep the Planet Habitable All life on Earth, and human civilization, are sustained by vital biogeochemical systems, which are in delicate balance. However, our species — due largely to rapid population growth and explosive consumption — is destabilizing these Earth processes, endangering the stability of the “safe operating space for humanity.” Advanced human societies emerged during an unprecedented period of stability on Earth. During the 12,000 years prior to the Industrial Revolution, our planet’s surface temperature varied by less than 1° Celsius (1.8° Fahrenheit) above or below the average for that entire period. As a result, life — both human and wild — thrived.