Almost three-quarters of Earth’s surface is covered by oceans, and another 10% is covered by ice sheets and glaciers. The ocean holds 60 times more carbon than the atmosphere and absorbs almost 30% of carbon dioxide (CO2) emissions from human activities causing the ocean to become both warmer and more acidic. The warming of Earth is primarily due to accumulation of heat-trapping greenhouse gases, and more than 90% of this trapped heat is absorbed by the oceans. 2023 set a new record for ocean heating.
As the ocean warms through the absorption of CO2, ocean acidification accelerates. Sometimes called “osteoporosis of the sea”, it is literally causing a sea change that is threatening the fundamental chemical balance of ocean and coastal waters from pole to pole as it creates conditions that eat away at the minerals used by oysters, clams, lobsters, shrimp, coral reefs, and other marine life to build their shells and skeletons.
The consequences are far reaching. Most ocean dwellers, from plankton to fish to whales, live in the upper section of the ocean, squarely in the zone where temperatures are increasing quickest. Many of these marine organisms are sensitive to even slight or short-lived changes in temperature. Corals, for example, are highly attuned to the temperature of the water in which they live. Warming of only about one degree Celsius can stress them out, causing them to “bleach.” That means they spit out the symbiotic algae that live inside them and usually provide them with much of their energy. Sometimes, corals can recover from these bleaching events. Other times, they can’t.
Already since 2016, half of all the coral in the Great Barrier Reef has died due to acidification, and Australia has downgraded its outlook to “very poor.” States are experiencing a host of other issues like disappearing whales, millions of dying starfish, and threats to fish species and the fishing industry.
CREDIT: The New York Times
