What Are Planetary Boundaries?

Planetary boundaries are scientifically defined limits that help guide human activity within the Earth’s environmental capacity. They represent thresholds in Earth's life-supporting systems such as, the climate, oceans, and ecosystems. If these thresholds are crossed, they could cause irreversible environmental change.

These boundaries are not arbitrary. They are based on research into how Earth's systems have behaved over thousands of years. Scientists ask:

•  At what point do natural systems become unstable?
   
•  How much pressure can we apply before a system change suddenly or irreversibly?

To stay within a "safe operating space" for humanity, human activity must be kept within these boundaries. The purpose is to ensure that future generations inherit a stable, resilient planet. The framework guides sustainable development that respects ecological limits.

This approach is changing the way that people think about the environment. It is no longer just about reducing harm but about staying within the physical boundaries of a functioning planet.