Broken seven of the nine “planetary limits” that we were not supposed to cross

Our planet is not doing very well, and we know it: climate change, loss of biodiversity, pollution, are drastically changing the environment in which our species has evolved and thrived for thousands of years. Where …

Broken seven of the nine "planetary limits" that we were not supposed to cross

Our planet is not doing very well, and we know it: climate change, loss of biodiversity, pollution, are drastically changing the environment in which our species has evolved and thrived for thousands of years. Where are we, though, exactly? This is the question that the Planetary Health Check aims to answer, a scientific check-up of the health of the planet launched by the Potsdam Institute for Climate Impact Research and other environmental organisations. The first report of this initiative – which will produce updates on an annual basis – was presented in recent days, and the response for now is not rosy: out of nine “planetary limits” identified by the research we have already exceeded six, and a seventh is in about to be breached. The health of the Earth, therefore, is starting to become at high risk.

The planetary limits not to be exceeded

As the authors of the report explain, the environmental challenges our planet is facing are a highly studied field. But in which, up to now, we have usually proceeded by analyzing each danger separately: global warming and pollution, and the effects that these have in terms of loss of biodiversity, or changes in the biogeochemical cycles that occur on our planet, are instead elements interconnected systems of a system, the terrestrial one, which currently guarantees the survival of human beings and other animal species. And that if changes are too radical, it may stop doing so in the future.

To analyze the resilience of the terrestrial environment as a whole, the concept of planetary boundaries has been proposed: the safety thresholds within which the environment can change, and exceeding which risks producing irreversible effects, becoming a threat to the survival of ecosystems and the habitability of the planet. And it is in these terms that the Planetary Health Check decided to carry out his check-up of the health of the Earth.

The document identifies nine planetary boundaries and, for each, one or two variables (13 in total) with which to measure their conservation status. Looking at their results, the diagnosis begins to become ominous: “The patient – ​​that is, our planet Earth – is in critical condition”, explained Johan Rockström, director of the Potsdam Institute for Climate Impact Research, presenting the report. “Six of the nine planetary boundaries have already been exceeded. The seventh shows itself to be under increasing pressure, meaning that we will soon see most of the planet’s health parameters in high-risk conditions.”

The planetary limits already exceeded are climate change, integrity of the biosphere, soil exploitation, availability of fresh water, stability of biogeochemical cycles and the introduction of new entities (i.e. the arrival of organisms, chemicals and synthetic materials in nature, of which no long-term effects are known). Ocean acidification is still below the warning threshold, but just barely. While only the atmospheric levels of aerosols and the reduction of the stratospheric ozone layer have not yet reached worrying levels.

The dangers, therefore, are evident. Unfortunately, the solutions are less obvious or simple. “We have known for a long time that we are compromising the resilience of the planet,” Rockström stressed. “This scientific update shows that, regardless of the scale on which we operate, each of our actions must consider the impact it can have on a planetary scale. Stewardship for our planet is therefore necessary in all sectors of the economy and society, to ensure security, prosperity and equity”.