Planetary boundaries: HOW HEALTHY IS PLANET EARTH?
Earth is a unique, living planet that sustains and nourishes us. But its ability to do so has its limits. If we breach its ‘planetary boundaries’ through our actions, we jeopardise life on Earth.
Planetary boundaries are like an ecological guard rail: they show us where we need to take measures to maintain the balance of Earth’s systems. They enable us to take targeted action to limit the damage and shape a sustainable future worth living.
EARTH IS LOSING ITS RESILIENCE
A research team led by Johan Rockström has identified nine key Earth systems and processes that ensure stable living conditions. In 2024, their annual Planetary Health Check revealed that Earth is in a state of increased risk and weakened resilience due to our actions (yellow area at the top of the figure).
Graphic: Status report: How healthy is Earth? (modif.) (from: Planetary Health Check. A Scientific Assessment of the State of the Planet. FIRST EDITION, 2024)
The diagram summarizes the planet’s “health check” using the planetary‑boundaries framework. For each of nine processes a color bar runs from green (safe operating space) through yellow/orange (increasing risk) to red/purple (high‑risk zone). Circular markers indicate the present value; arrows show direction of change. Processes shown: stratospheric ozone depletion (currently within the safe zone), atmospheric aerosol loading (regional), ocean acidification (near the boundary and rising), freshwater change with “green” and “blue” water (partly beyond the boundary), land‑system change (beyond), climate change (well beyond), biogeochemical flows of phosphorus and nitrogen (far beyond), novel entities such as synthetic chemicals and plastics (beyond), and biosphere integrity including functional integrity and genetic diversity (beyond). The caption cites the source: Planetary Health Check, First Edition, 2024.
Only three processes are still within a ‘safe’ operating space (green areas in the figure): here, humans can still act without taking major risks for Earth’s systems. We have already exceeded the limits for six processes – the further to the right an area is on the diagram and the redder it is, the more so. For seven of the nine processes, the trend is increasing (arrow pointing to the right; the horizontal lines indicate that the current position is uncertain). This increases the risk of abrupt and irreversible environmental changes that can jeopardise human wellbeing.
CHAIN REACTIONS
If one system becomes more unstable, this affects other systems. Rising temperatures, for example, accelerate the loss of biodiversity, and higher CO₂ levels lead to ocean acidification. The loss of biodiversity has a direct impact on the stability of ecosystems that provide us with clean water, air and food. Overstepping the boundaries therefore not only means problems for nature, but also has consequences for our economy, our health and our future.
HOPE THROUGH RESPONSIBILITY
There is hope. But the necessary changes require global co-operation and the willingness of every one of us to take responsibility. If we stay within the planetary boundaries, we can help to ensure that Earth remains a liveable place – for us and our children.