Warning that the limit of ocean acidification has been exceeded

2025/06/12 Galarraga Aiestaran, Ana - Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Ingurumena
• Ozeanografia
• Ekologia

A year and a half ago, six of the nine planetary boundaries had already been overcome, and a seventh was about to be overcome, Elhuyar magazine confirmed in its report “Out of Security Boundaries”. This seventh was the acidification of the oceans, which has now been warned through the journal Global Change Biology that it has already been overcome.

The planetary boundary defines the conditions necessary to sustain life: if the boundary is exceeded, habitability is compromised. In the case of the oceans, acidification is considered harmful to marine ecosystems. Indeed, the article explains that damage to calcifying species is already evident, resulting in a 43% reduction in habitat for tropical and subtropical coral reefs, 61% for polar pteropods, and 13% for coastal bivalves.

Ocean acidification is directly linked to climate change, as the pH of water decreases due to the absorption of carbon dioxide from the atmosphere. The researchers say that by 2020 it was at dangerous values and that the situation is worse in deep water than in shallow water.

To address this, they stress the need to reduce carbon emissions. Climate change, along with the integrity of the biosphere, land use, fresh water, phosphorus and nitrogen cycles, and environmental pollutants, is another of the limits that have been overcome. Atmospheric aerosols and stratospheric ozone are the ones that have not been overcome, for the moment.