Planetary Boundaries

Groundbreaking study quantifies safe and just Earth system boundaries

We have transgressed the just boundary for climate change which means that already today people around the world suffer from its effects. Photo: UN Photo/Logan Abassi via Flickr.

International commission proposes new safe and just boundaries for maintaining a healthy planet and protecting people from significant harm

Story highlights

  • New study established safe and just boundaries for the Earth system
  • Safe boundaries ensure stable and resilient conditions on Earth, and just boundaries minimise human exposure to significant harm
  • Humankind has already transgressed several of these boundaries

A JUST WORLD ON A SAFE PLANET: For the first time, a team of more than fifty scientists from around the globe assessed and quantified not only what is a safe operating space for humankind, but also what is a just one. They define justice as avoiding significant harm to people across the world, now and in the future, but also include other species in their analysis.

“The new research provides safe and just Earth system boundaries for five critical domains that play a key role in life support and Earth stability. It is also based on what’s needed to minimize significant harm to humans as a result of changes in the Earth system, such as biodiversity loss and altered freshwater flows,” explains one of the lead authors, Centre researcher Steven Lade.

The study was developed by the Earth Commission, an international network of scientists convened by Future Earth in Sweden.

Safe and just

The work of the commission builds largely on the well-known planetary boundaries framework, which identifies nine processes that regulate the stability and resilience of the Earth system. In the new study, the researchers explored five of these processes and quantify their justice implications: Climate, biodiversity, freshwater, nutrient cycles, and aerosol pollutants.

Our results are quite concerning: Within the five analysed domains, several boundaries, on a global and local scale, are already transgressed.

Johan Rockström, lead author

For these and several sub-categories, the researchers established safe boundaries – that ensure stable and resilient conditions on Earth – and just boundaries – that minimize human exposure to significant harm.

Danger zone

Adding this justice perspective means that the operating space for many of the original boundaries is tightened. For climate, for example, humankind as a whole is considered to be relatively safe up until 1.5 degrees of global warming. After that, unprecedented climate tipping points become much more likely. But, already the current temperature rise of 1.2 degrees causes significant harm to people across the world. That’s why the scientists set the just Earth System Boundary for climate at 1.0 degrees.

Zoom image

Visualization of safe Earth System Boundaries, just Earth System Boundaries, cases where safe and just boundaries align and current global states. Credit: Earth Commission.

Similarly, the just operating space is smaller than the safe one for several of the other boundaries.

“Our results are quite concerning: Within the five analysed domains, several boundaries, on a global and local scale, are already transgressed. This means that unless a timely transformation occurs, it is most likely that irreversible tipping points and widespread impacts on human well-being will be unavoidable. Avoiding that scenario is crucial if we want to secure a safe and just future for current and future generations,” says another of the study’s lead authors, Centre co-founder Johan Rockström who also co-chairs the Earth Commission.

Read: Safe and just Earth system boundaries »

Published: 2023-05-31


Rockström, J., Gupta, J., Qin, D., Lade, S.J., Abrams, J.F., Andersen, L.S., Armstrong McKay, D.I., Bai, X., Bala, G., Bunn, S.E., Ciobanu, D., DeClerck, F., Ebi, K., Gifford, L., Gordon, C., Hasan, S., Kanie, N., Lenton, T.M., Loriani, S., Liverman, D.M., Mohamed, A., Nakicenovic, N., Obura, D., Ospina, D., Prodani, K., Rammelt, C., Sakschewski, B., Scholtens, J., Stewart-Koster, B., Tharammal, T., van Vuuren, D., Verburg, P.H., Winkelmann, R., Zimm, C., Bennett, E.M., Bringezu, S., Broadgate, W., Green, P.A., Huang, L., Jacobson, L., Ndehedehe, C., Pedde, S., Rocha, J., Scheffer, M., Schulte-Uebbing, L., de Vries, W., Xiao, C., Xu, C., Xu, X., Zafra-Calvo, N. & Zhang, X. 2023. Safe and just Earth system boundaries. Nature.

DOI: 10.1038/s41586-023-06083-8

Link to publication


News & events