Planetary boundaries: The Upper Limit of the Sufficiency Corridors

By Emile Balembois 
2025-03-14

The Planetary Boundaries framework is a scientific concept developed to define the safe operating space for human activities on Earth. Introduced by Johan Rockström and colleagues in 2009 (external link), it identifies nine critical processes that regulate the stability and resilience of the Earth system, such as climate change, biodiversity loss, and biogeochemical cycles. By staying within these boundaries, humanity can avoid triggering large-scale, abrupt, or irreversible environmental changes.  

This framework offers a dual benefit: it provides a comprehensive assessment of the state of key biogeophysical components impacted by human activities, and it establishes a boundary for each of these components. By adopting a precautionary approach, each boundary is set based on the risk of the Earth system deviating from the Holocene epoch-a period that began 10,000 years ago and created ideal conditions for human civilization to flourish.  

As of today, some of the boundaries affected by human activities have already been transgressed (e.g., a CO2 concentration of 350 ppm for climate change), and others are quantified with large uncertainties (e.g., novel entities or changes in biosphere integrity). Importantly, planetary boundaries do not account for the uneven distribution of harm among populations in a changing environment.

The framework has been extended in 2023 (external link) to the Earth System Boundaries framework, offering specific, actionable targets that are both safe (precautionary approach) and just (principle of no significant harm to populations). Accordingly, a safe boundary for climate change is 1.5°C of global warming by the end of the century. However, the just boundary is 1°C of global warming to mitigate the already visible impacts of climate change. 

Considering Planetary Boundaries as the upper limit of the sufficiency corridors provides a clear, science-based guideline for ensuring that human development does not compromise the Earth's ability to support life. An example of these corridors when Earth System Boundaries are the upper limit is shown in the Figure. Sufficiency emphasizes the interconnectedness of the boundaries, highlighting the need for holistic approaches in policy design and practice. Having actionable targets that integrate justice principles aligns the Planetary Boundaries framework with the equity imperative of sufficiency (external link) as defined in philosophy.   

Figure: Representation of a 2018 assessment of the state of the planet Earth in terms of corridors where the Earth system boundaries are the upper limit and the impacts induced by access to a decent living standards for all are the lower limit (Gupta et al., 2024 (external link) – Figure 22):

This assessment distinguishes between safe (e.g. 1.5°C of global warming for climate) and just (e.g 1.0°C of global warming for climate) boundaries. 2 different levels of decent living standards are represented in dashed blue lines (value of these standards given in Gupta et al., 2024 (external link) - Table 3).