Richardson, K., Steffen, W., Lucht, W., et al. (2023). Earth beyond six of nine planetary boundaries. Science Advances 9, eadh2458 (13 September 2023).
The 2023 update to the planetary boundaries framework originally proposed by Rockström and colleagues in 2009 and extended by Steffen et al. in 2015. The paper finds that six of the nine boundaries are now transgressed: climate change, biosphere integrity, land-system change, freshwater change, biogeochemical (nitrogen and phosphorus) flows, and novel entities. The paper’s own summary: this planetary boundaries framework update finds that six of the nine boundaries are transgressed, suggesting that Earth is now well outside the safe operating space for humanity.