Six out of nine key planetary boundaries have been broken, while a seventh is set to be imminently breached, according to a “first-of-its-kind” planetary health check report.
Each of the boundaries is a bit like a cog in the machine that helps the planet to stay stable and resilient, allowing humanity to continue surviving and thriving. Once a boundary is breached, the risk of permanently damaging Earth’s life support systems increases, as does the risk of crossing tipping points that cause irreversible changes.
The new report argues that the following planetary boundaries have already transgressed beyond the “safe operating space for humanity”: freshwater change, land system change, climate change, modification of biogeochemical flows, the introduction of novel entities, and change in biosphere integrity.
A seventh boundary – ocean acidification – is currently within the safe zone but is set to be breached in a few years.
Two remaining planetary processes – stratosphere ozone depletion and an increase in atmosphere aerosol loading – remain in the safe zone and aren’t expected to break beyond their safe limit in the near future.
The new update on the Planetary Boundaries framework shows that six of the nine boundaries are transgressed.
Image credit: Azote for Stockholm Resilience Centre, based on analysis in Richardson et al 2023.
The Planetary Health Check 2024 report, part of a new peer-reviewed study, was created by scientists at the Potsdam Institute for Climate Impact Research (PIK) in Germany.
“When we look at the trends of Earth’s health indicators, we see that soon the majority of them will be in the high-risk zone. We need to reverse this trend. We know that all Planetary Boundary processes act together and each one needs protection to protect the whole system,” Boris Sakschewski, co-lead of PBScience and lead author of the report, said in a statement.
The researchers explain how Earth’s planetary health is often studied as isolated issues, despite being deeply interconnected and highly complex. If we’re going to solve the world’s environmental problem, they argue that it’s important that we address it as a multi-dimensional matter.
Fundamentally, though, all these problems link back to a few human activities, including replacing nature with other land uses, changing the amount of water in rivers and in soil, introducing synthetic chemicals to the environment, and – the big one – the emission of greenhouse gases.
“The Planetary Health Check is a major leap forward in our collective mission to understand and protect our planet. We have known for some time that we are weakening the planet’s resilience. This scientific update shows that irrespective of what scale we operate on, all actions need to consider impacts at the planetary scale,” added Johan Rockström, PIK Director, Co-Lead of PBScience and Pioneer of the Planetary Boundaries Framework.
“Stewardship of the planet is necessary in all sectors of the economy and in societies, for security, prosperity, and equity. By quantifying the boundaries for a healthy planet, we provide policy, economics, and business with the tools needed to steer away from unmanageable risks.”
The study is published in the journal Science.
