Crossing the Threshold: Growing Global Concerns as Six Critical Planetary Boundaries are Breached

In the latest update regarding the Planetary Boundaries framework, it is evident that six out of the nine defined boundaries have been surpassed. This assessment, presented by Azote in collaboration with the Stockholm Resilience Centre and based on the analysis conducted by Richardson et al. in 2023, paints a concerning picture of our planet’s current state.

This new study provides an updated perspective on the Planetary Boundary framework, revealing the increasing impact of human activities on our planet. These activities pose a growing risk of triggering profound and irreversible alterations to Earth’s overall environmental conditions.

For more than three billion years, the interplay between life, as symbolized by the planetary boundary known as Biosphere Integrity, and the climate has regulated the environmental conditions on Earth. Human actions, such as the transformation of natural landscapes, modifications in water levels in rivers and soil, the introduction of synthetic chemicals into the environment, and the release of greenhouse gases into the atmosphere, all influence these critical interactions.

Preserving and respecting these interactions within the Earth system, maintaining them within the parameters that have governed Earth’s conditions for approximately the last 12,000 years, is essential to prevent potentially catastrophic shifts in the Earth’s ability to sustain modern civilizations.

Planetary Boundaries and Their Impact on Humanity

The concept of “planetary boundaries” encompasses various aspects of the global environment that determine the stability and habitability of our planet for human life. The extent to which these safe boundary levels are breached is a direct consequence of human activities affecting these components. This framework draws upon the latest scientific insights into the functioning of the Earth system to establish a “safe operating space” for humanity by setting limits on how much human activities can influence critical processes without risking irreversible changes in Earth’s supporting conditions.

For the first time, comprehensive metrics for all nine boundaries have been presented. Alarming findings reveal that six of these boundaries have been transgressed, and the extent of transgression is increasing for all boundaries except for the degradation of Earth’s ozone layer. This underscores the need for a global focus on climate alone being insufficient. Urgent attention must be directed toward the development of Earth system models that accurately replicate the interactions between these boundaries, particularly the connections between Climate and Biosphere Integrity.

This groundbreaking study, published in the journal Science Advances, marks the third update to the framework and involves the collaborative efforts of twenty-nine scientists from eight different countries.

Earth’s “Blood Pressure” on the Rise

The escalating breaches of these boundaries are a cause for concern, as highlighted by Katherine Richardson, a professor at the Globe Institute and Leader of the Sustainability Science Centre at the University of Copenhagen, who led the study. She likens this situation to monitoring one’s blood pressure, where a reading above 120/80 doesn’t guarantee a heart attack but significantly elevates the risk. Similarly, for the sake of current and future generations, efforts are needed to reduce the pressure on these six planetary boundaries.

One pivotal conclusion from this research emphasizes the necessity of focusing on the interactions between these boundaries. Johan Rockström, Director of the Potsdam Institute for Climate Impact Research (PIK) and the original proponent of the framework in 2009, asserts that while addressing human-induced climate change is crucial, it cannot be the sole focus. Preserving the integrity of the biosphere stands as the second fundamental pillar for Earth’s stability. Hence, mitigating global warming and safeguarding a functional biosphere must be pursued hand in hand.

Biomass Usage and Its Impact on Biodiversity

The call to respect the Land Use Change boundary brings attention to the growing worldwide adoption of biomass as an alternative to coal, oil, and gas. Biomass, a product of photosynthesis, is the energy source that supports biodiversity by converting solar energy into a form usable by other organisms.

Richardson’s study reveals that humans are appropriating nearly 30% of the energy that was once available to sustain biodiversity before the Industrial Revolution. This significant reduction in energy accessible to nature likely contributes to biodiversity loss. Therefore, the study suggests adopting Human Appropriation of Net Primary Production (HANPP), which measures biomass use, as one of the metrics when assessing human impacts on biodiversity.

The Imperative for Enhanced Earth System Models

In light of these findings, it becomes evident that adhering to scientifically defined boundaries is paramount for navigating our current situation, marked by escalating, potentially catastrophic planetary risks. While we have already acknowledged this necessity in the context of climate change, as exemplified by the Paris Agreement’s adoption of the 1.5°C limit, the study underscores that this is insufficient. Planetary Boundaries science provides a vital “guide for action” if we genuinely aim to ensure prosperity and equity for all on Earth. This extends beyond climate considerations and demands innovative Earth system modeling, analysis, and concerted efforts to protect, restore, and bolster planetary resilience.

Katherine Richardson adds a final note of urgency, hoping that this study serves as a clarion call to the international community, emphasizing the imperative of limiting our impact on the planet to safeguard the conditions essential for the flourishing of advanced human societies.

Frequently Asked Questions (FAQs) about Planetary Boundaries

More about Planetary Boundaries

• Science Advances Journal
• Stockholm Resilience Centre
• The Planetary Boundaries Framework
• Katherine Richardson – Globe Institute
• Potsdam Institute for Climate Impact Research (PIK)
• Paris Agreement
• Montreal-Kunming COP15
• Human Appropriation of Net Primary Production (HANPP)