7 of 9 Planetary Boundaries at Risk

A recent health assessment of Earth indicates that seven out of nine key life-support systems may already be failing. Previously, scientists believed the planet had crossed six planetary boundaries, but that number is now poised to increase, as reported by The Guardian.

According to a new report from the Potsdam Institute for Climate Impact Research, industrial civilization is nearing the breach of the seventh planetary boundary. In fact, researchers suggest that we may have already crossed this boundary—ocean acidification, a serious threat to marine ecosystems.

This report builds on years of research into the nine planetary boundaries—critical systems and processes that support life on Earth. These boundaries help maintain global stability.

Last year, scientists concluded that six critical thresholds had been exceeded. High-risk areas include climate change, the introduction of new species, changes to biosphere integrity, and disruptions in biogeochemical cycles.

Meanwhile, land-system change and freshwater availability have also been impacted, though to a lesser degree. The situation across all these areas has worsened, though ozone depletion remains stable, and atmospheric aerosol levels have shown improvement.

Now, scientists have recorded another alarming milestone: Earth has breached an additional planetary boundary. According to climate physicist Levke Caesar, a co-author of the report, there are two primary reasons for concern regarding ocean acidification:

1. One of the ocean’s indicators remains within safe operating conditions but is nearing the boundary of that safety zone.

2. Research indicates that current conditions are already negatively affecting some marine species.

Observations show that ocean acidification has intensified globally, with the most severe effects observed in the Southern and Arctic Oceans. Ocean acidification occurs when atmospheric carbon dioxide is absorbed by seawater, increasing its acidity.

This process harms calcifying organisms, potentially leading to the collapse of entire marine food chains. Scientists also worry that acidification weakens the ocean’s capacity to act as a critical carbon sink.

The report underscores the interconnectedness of all nine planetary boundaries. Human-caused disruptions to one system can ripple across others. The authors caution against treating these issues in isolation, as the Earth’s systems operate as an integrated network, where changes in one area inevitably affect others.

First introduced in 2009, the concept of planetary boundaries outlines nine crucial systems that support life on Earth. Violating these boundaries could destabilize the planet, threatening sustainability and habitability.