An international team of researchers has assessed the impact of carbon dioxide on the oceans. Their study, published in
Global Change Biology, is based on historical data and computer models. Ocean acidification, a little-known phenomenon, is reaching alarming proportions.
The increased absorption of CO2 by the oceans is altering their chemical composition. This reaction turns seawater into carbonic acid, reducing carbonate ions. These ions are essential for the formation of shells and skeletons of marine organisms. Coral reefs, among the most affected, are seeing their habitats rapidly deteriorate.
Scientists have identified nine planetary boundaries, six of which have already been crossed. Ocean acidification represents the seventh, with calcium carbonate reductions reaching 20%. These changes affect 40% of surface waters and 60% of deep waters. The first observations date back at least five years.
Unlike a point of no return, this boundary can still be pushed back. Reducing greenhouse gas emissions remains the key solution. Researchers emphasize the urgency of acting to preserve marine ecosystems. The consequences of inaction would, on the contrary, be irreversible for ocean biodiversity.
How are planetary boundaries defined?
Planetary boundaries are scientific limits identifying thresholds that should not be exceeded to avoid dangerous environmental changes. They cover nine critical areas, including climate and biodiversity.
These boundaries aim to maintain Earth in a stable state conducive to human life. Crossing a boundary increases the risk of major ecosystem disruptions.
Among these boundaries, six have already been crossed, according to researchers. Ocean acidification adds to this list, highlighting the scale of environmental challenges.
These concepts guide environmental policies and conservation efforts. They remind us of the need for sustainable management of natural resources.