We live in the Anthropocene era, in which humans are the single largest modifier of planet Earth.
The consequences of there being seven billion of us on the planet are more than the Earth’s natural biophysical and geological systems can process.
The concept of ‘planetary boundaries’ is one of defining a ‘safe operating space’ for human societies to develop and thrive, based on the functioning and resilience of the Earth.
Based on the human-induced alterations in the natural environment, nine planetary boundaries have been identified, each with defined threshold limits. Crossing these boundaries will result in deleterious consequences for all species on Earth, and damage the possibility of achieving a sustainable future.
In this briefing, we explore the approach, concept and limits of planetary boundaries, and discuss the influence of population growth on these boundaries.
The nine planetary boundaries are based on three scientific principles:
- the level of usage of non-renewable fossil resources
- the level of usage of the biosphere, and exploitation of natural ecosystems
- the level of Earth’s capacity to absorb and dissipate human waste flows
Climate change and the integrity of the biosphere are the two most important limits, because they influence the threshold limits of the remaining boundaries.
According to recent estimates, we have already crossed four of the nine planetary boundaries, highlighting the current scale of human-induced alterations in the environment.
If these changes are not reversed, and if the current scale of depletion of natural resources continues, we will jeopardise our future by driving innumerable species to extinction.
Population Matters asserts that stabilising population growth is essential if we are to avoid crossing the defined threshold limits of the nine planetary boundaries.
The concept of Planetary Boundaries is thus an effective tool to aid decision-makers by defining the safe operating space for humanity and a sustainable future.