Planetary Boundaries

Planetary boundaries represent a synthetic conceptual framework that identifies nine key Earth system processes that operate on a planetary scale. These processes include climate change, ozone depletion, atmospheric aerosol loading, ocean acidification, global freshwater use, chemical pollution, earth system change, biological diversity and biogeochemistry. The aim of planetary limits is to define a “safe operating space” for the Earth system. They aim to maintain a sustainable balance between human actions and natural processes, thereby preserving the Earth’s capacity to support life as we know it. 

Figure 1. shows that six of the nine planetary boundaries are being crossed, while pressure on all processes is simultaneously increasing. First proposed by Johan Rockström and colleagues in 2009, these boundaries were fully quantified in 2023, revealing that six of the nine have already been crossed, increasing the risk of large-scale environmental shifts.

Figure 1. The 2023 planetary boundary update. Licensed under CC BY-NC-ND 3.0. Credit: “Nitrogen for the Stockholm Resilience Centre, based on Richardson et al 2023 analysis”.