In a stark reminder of the consequences of human activities on our planet, a new study highlights the growing impact of these actions on Earth’s vital boundaries. These planetary boundaries represent the delicate balance that sustains the stability and liveability of the planet for all living beings.
For more than three billion years, the interactions between life (represented by Biosphere Integrity) and climate have shaped Earth’s environmental conditions. However, human actions, such as altering natural landscapes, changing waterways, introducing synthetic chemicals into the environment, and emitting greenhouse gases, are increasingly disrupting these crucial interactions.
PLANETARY BOUNDARIES: GUARDIANS OF OUR ENVIRONMENT
The “planetary boundaries” framework defines the limits within which human activities should operate to prevent triggering irreversible changes in Earth’s conditions. These boundaries encompass critical processes that regulate the planet’s stability and suitability for human civilizations.
For the first time, this study provides metrics for all nine planetary boundaries. Alarmingly, it finds that six of these boundaries have been breached, and transgressions are on the rise in all areas except the Earth’s ozone layer. While breaching a single boundary doesn’t guarantee disaster, it is akin to an elevated “blood pressure” for the planet, indicating increased risks.
PLANETARY BOUNDARIES: A CALL TO ACTION
Katherine Richardson, the leader of the study and a professor at the Globe Institute, emphasizes the importance of recognizing this trend: “Crossing six boundaries in itself does not necessarily imply a disaster will ensue, but it is a clear warning signal. We can regard it as we do our own blood pressure. A BP over 120/80 is not a guarantee of a heart attack, but it increases the risk of one. Therefore, we try to bring it down. For our own—and our children’s—sakes, we need to reduce the pressure on these six planetary boundaries.”
Johan Rockström, the Director of the Potsdam Institute for Climate Impact Research, underlines the need for a broader perspective: “Focus on human-caused climate change is not enough if we want to protect the earth system from irreversible harm. Next to climate change, the integrity of the biosphere is the second pillar of stability of our planet. Our research shows that mitigating global warming and saving a functional biosphere for the future have to go hand in hand.”
The Vital Role of Biomass in Biodiversity
One area of concern is the Land Use Change boundary, which draws attention to the increasing global use of biomass as an alternative to fossil fuels. This has profound implications for biodiversity, as biomass is vital for supporting diverse ecosystems.
EMBRACING SCIENCE-DEFINED BOUNDARIES
The study suggests adopting Human Appropriation of Net Primary Production (HANPP), a metric that measures biomass use, when assessing human impacts on biodiversity. It highlights that humans are appropriating approximately 30% of the energy that once supported biodiversity before the Industrial Revolution, potentially contributing to biodiversity loss.
The study’s message is clear: we must adopt a science-defined approach to operate within Earth’s boundaries to prevent catastrophic risks on a planetary scale. While progress has been made in recognizing these boundaries for climate and biodiversity, it’s evident that more comprehensive Earth system models and concerted efforts are needed to protect and rebuild planetary resilience.
Katherine Richardson concludes, “Hopefully, this new study will serve as a wake-up call for many and increase focus in the international community on the necessity of limiting our impacts on the planet to preserve and protect the Earth conditions that allow advanced human societies to flourish.”