A new report by the Potsdam Institute for Climate Impact Research (PIK) warned Wednesday that most of Earth’s critical life-support systems are under threat.
The Planetary Health Check report by climate scientists shows that seven of nine critical stress limits have been exceeded. A new concern is ocean acidification, which happens when seawater becomes more acidic as its pH drops.
The report provides an assessment of the state of the Earth. It is based on planetary boundaries - nine processes that regulate the stability, resilience and life-sustaining functions of the planet, the study notes.
"More than three-quarters of the Earth's vital system functions are no longer within safe limits. Humanity is leaving its safe operating space and thus increasing the risk of destabilizing the planet," said PIK Director Johan Rockström, co-author of the report.
According to the report, the seven thresholds that have been exceeded are: climate change, biosphere integrity, land use change, freshwater systems change, changes in the nitrogen and phosphorus cycles, anthropogenic substance inputs and ocean acidification.
Researchers report that two of the identified stress limits are still within safe limits: exposure to aerosols (air pollution) and the ozone layer.
Once a limit is exceeded, researchers say, the risk of permanently damaging the Earth's vital functions increases, as does the likelihood of tipping points being exceeded, making changes irreversible.
Scientists monitor these limits using key indicators. According to the Planetary Health Check, the main cause of ocean acidification is the burning of fossil fuels, exacerbated by deforestation and land use change.
Oceans absorb large amounts of man-made carbon dioxide from the atmosphere, causing their water to become more acidic.
As a result of these factors, the oceans are increasingly losing their stabilizing role in the Earth system, according to the research team.
The consequences are noticeable: cold-water corals, tropical reefs and Arctic ecosystems are under pressure. In addition, there are negative consequences for entire food chains and food security, including for humans.
According to PIK, tiny sea snails, known as winged snails, are already showing damage to their shells. They are an important source of food for fish and whales.
