The world’s oceans have crossed a dangerous acidity threshold for the first time, scientists warned in the latest Planetary Health Check.
The Potsdam Institute for Climate Impact Research reported that surface pH has dropped by 0.1 units since the industrial era, a 30-40% rise in acidity. This is now the seventh of nine planetary boundaries that humanity has transgressed.
The change, driven by fossil fuel burning, threatens corals, Arctic ecosystems, molluscs and the marine food web, raising risks for human food security and coastal economies. Scientists also fear reduced ocean ability to absorb heat and draw down carbon dioxide.
The report highlights worsening trends in climate change, biodiversity loss, land use, freshwater use, nutrient flows and chemical pollution. Levke Caesar of the Planetary Boundaries Science Lab said: “Looking at this data, when I allow myself to connect to it emotionally, then I am afraid. This really scares me.”
Despite the dire findings, scientists stressed solutions remain possible through cutting fossil fuels, reducing pollution and better fisheries management. They pointed to the ozone layer’s recovery and reduced aerosol pollution as evidence that international action can reverse damage.
Johan Rockström, the institute’s director, said: “We are witnessing widespread decline in the health of our planet. But failure is not inevitable; failure is a choice.”
