A warning has been issued by scientists regarding the detrimental effects of greenhouse gas emissions from burning fossil fuels on the world’s oceans. The increased acidity poses a threat to shellfish, corals, and their pivotal role in combating climate change. Ocean acidification has breached a critical threshold, identified as the newest “planetary boundary” to be surpassed, signaling potential risks to crucial planetary systems essential for human civilization.
The Planetary Health Check report reveals that other planetary boundaries, including elevated levels of chemical pollution, atmospheric warming, and disruptions to the nutrient cycle, have already indicated looming dangers for humanity. Johan Rockström, the director of the Potsdam Institute for Climate Impact Research, cautioned that exceeding these boundaries elevates the risk of irreversible changes that could compromise Earth’s habitability.
Incorporating oceans into the list of planetary boundaries raises significant concerns due to the dependence of billions of people on marine resources. The continuous acidification of oceans not only jeopardizes fisheries vital for sustenance but also diminishes the ocean’s capacity to sequester carbon dioxide and regulate global temperatures.
As humans release carbon dioxide into the atmosphere through fossil fuel combustion, the oceans absorb over a quarter of this CO2. This absorption process leads to increased acidity, akin to carbonating a soft drink, as explained by Christopher Harley, a climate change and ocean expert. However, this chemical transformation diminishes the availability of a mineral crucial for the development of marine organisms like shellfish and coral.
The planetary boundary report highlights the declining aragonite saturation in the ocean, negatively impacting various species’ growth and shell development. From plankton to mussels, crabs, and oysters, these organisms exhibit adverse effects such as stunted larval growth and weakened shells due to ocean acidification.
Regional disparities in ocean acidification intensity are noted, with higher latitude regions like Canadian waters facing elevated risks. The accelerated acidification in polar regions, exacerbated by carbon absorption in colder waters and melting glaciers, intensifies the challenge. Despite the perception of ocean acidification as a gradual process, its impact on marine ecosystems is becoming increasingly evident, particularly in regions like British Columbia.
Experts unanimously emphasize the global nature of this issue, necessitating a substantial reduction in carbon dioxide emissions. Addressing the root cause of ocean acidification through decarbonization is crucial to safeguarding marine ecosystems and mitigating climate change risks.