- The newly published 2025 Planetary Health Check report confirms transgression of the ocean acidification planetary boundary — the seventh Earth system threshold crossed, putting a “safe operating space for humanity” at risk. Oceans act as a key climate stabilizer, resilience builder and Earth life-support system.
- Marking the launch of the 2025 Planetary Health Check, Mongabay speaks with report co-author and renowned Earth system scientist Johan Rockström about how the transgression of planetary boundaries is eroding environmental justice — the right of every human being to life on a stable, healthy planet.
- Rockström, who led the international team of scientists who originated the 2009 planetary boundary framework, also speaks about the failure to achieve a U.N. plastics treaty in August and the challenge of accomplishing planetwide sustainability in a time of widespread armed conflict and political instability.
- He likewise emphasizes the need to bring the U.S. back to the negotiating table at COP30, the U.N. climate summit scheduled for November, in Belém, Brazil, and addresses the importance of inserting the planetary boundaries framework into those talks.
Initiated in 2024, the Planetary Health Check is a comprehensive, science-based global initiative dedicated to measuring and maintaining Earth systems critical to life as we know it.
These annual reports were created to provide a regular, comprehensive assessment of the state of our world, utilizing the most current planetary boundaries science — monitoring changes, gauging risks, identifying urgent actions needed, developing solutions and determining progress in maintaining a “safe operating space for humanity.”
The just-published 2025 assessment finds that seven out of the nine critical planetary boundaries (PBs) have been breached: climate change, change in biosphere integrity, land system change, freshwater change, modification of biogeochemical flows, the introduction of novel entities, and now, ocean acidification.
All of these Earth system boundary transgressions show escalating trends, threatening further deterioration and destabilization of planetary health in the near future. Just two PBs remain within the safe operating space: increase in atmospheric aerosol loading (with an improving global trend) and stratospheric ozone depletion (currently stable).
Earth System scientist Johan Rockström, director of the Potsdam Institute for Climate Impact Research (PIK) in Germany, spoke to Mongabay on the occasion of the launch of the Planetary Health Check 2025 report, which announces the transgression of the ocean acidification boundary — the seventh Earth system boundary threshold crossed, putting the safe operating space for humanity at grave risk.
PIK’s director is co-author of the 2025 report and author of the book and video documentary Breaking Boundaries: The Science of Our Planet (2021), which explains the planetary boundaries framework, which was developed in 2009 by an international scientific team led by Rockström. This framework was also the inspiration for the Frontiers Planet Prize, which awards three prizes of $1 million every year to research offering the greatest potential to address the ecological crisis.
The newly released report signals a planetary emergency requiring immediate and coordinated global action, say scientists. (This interview has been lightly edited for brevity and clarity.)
This iconic planetary boundaries (PBs) diagram visually represents the current status of the nine critical PB processes that regulate our planet’s health. Each Earth system is quantified by one or more control variables based on observational data, model simulations and expert opinions. Image courtesy of Planetary Health Check 2025.
Mongabay: The Planetary Health Check 2025 report announces the transgression of the ocean acidification boundary (the decreasing of pH in seawater caused by the absorption of atmospheric CO₂), the seventh Earth boundary threshold to be crossed due to humanity’s actions. What does this mean and why is it relevant to all of us?
Johan Rockström: The latest update — based on data observations as to where [ocean] acidification is developing, and on the refined methodology for making those observations — concludes, unfortunately, but not unexpectedly, that the ocean acidification boundary has now been breached.
This is a very worrying trend, because the ocean is under multiple planetary pressures: [including] the faster than expected heat increase, the ocean acidification boundary now being breached, continuous eutrophication, and the loss in biodiversity due to overfishing and other causes. So, we have an ocean system on planet Earth, across all marine systems, under high and increased pressure.
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Julian Reingold, Mongabay, 24 September 2025. Full article.
