Newer studies indicate that ocean acidification has in all probability already crossed a dangerous threshold. We crossed that threshold—the so-called “planetary boundary”—approximately five years ago. This disturbing trend throws the natural chemistry of our oceans completely out of whack. It poses extremely pressing questions regarding the ramifications on global marine ecosystems and climate. A collaborative study by a diverse team of planetary scientists, ecologists, and marine biologists contributed to these findings. In their research, they discovered that roughly 40% of the world’s ocean surface water and nearly 60% of subsurface water are experiencing drastic decreases in calcium carbonate levels—a crucial indicator of ocean acidification.
Ocean acidification is one of the nine planetary boundaries we have already crossed. These nine boundaries mark out the safe and just operating space for humanity. Seawater absorbs more CO2 from the atmosphere than it can handle. Consequently, pH levels decrease and the availability of carbonate declines. This process has reduced calcium carbonate by 20% from pre-Industrial Revolution baseline levels. With climate change and future effects on our beloved marine life very much at stake, this trend is troubling.
Research Methodology and Findings
To help defend their assertions regarding the impacts of ocean acidification, the research team drew upon a depth of resources. They referenced discoveries from earlier studies to support their claims. It was only with their all-encompassing approach that they could analyze data longitudinally and use it to gauge the health of our ocean water chemistry today. The research appeared in the journal Global Change Biology. This important piece of research moves the needle further in our understanding of this complex and often harmful environmental phenomenon. Our study has been given the DOI 10.1111/gcb.70238 for citation purposes.
Seventeen such institutions from the U.S. joined their counterparts from the U.K. Combined, they represented an inspiring community and local government effort to address this urgent environmental crisis. The research team integrated various scientific perspectives to achieve a holistic understanding of ocean acidification. This partnership ultimately allowed them to show just how bad the problem has become. What their findings reveal is that surface water has taken the brunt of the impact. In parallel, they reported alarming shifts in the ecology of subsurface waters helping to deepen the ecological crisis further.
Implications for Marine Ecosystems
According to the EAT-Lancet Commission report, crossing the planetary boundary for ocean acidification has serious consequences for marine ecosystems. When pH decreases (a measure of acidity), there are fewer carbonate ions available. This shift leaves calcifying organisms—such as corals, mollusks, and various plankton species—out to dry, literally inhibiting their ability to produce shells and skeletons. This anthropogenic disruption poses a major risk to biodiversity and may result in cascading impacts across marine food webs.
The implications are not just at the level of individual species, but entire ecosystems. Coral reefs which need very stable pH levels, economic and ecological conditions are especially sensitive. These marine ecosystems are critical habitats for hundreds of marine species, including commercially important fish and shellfish, and provide protective coastal infrastructure and support tourism through their beauty. The destruction of these habitats would severely affect our marine species. It would jeopardize the livelihoods of human communities that depend on healthy oceans.
A Broader Context
That same OCB study on ocean acidification characterizes a pressing need for global coordination and awareness in the face of rapid environmental change. We are today transgressing a seventh planetary boundary. That underscores the almost unbelievable third act challenges we created for ourselves by putting our economy on a collision course with nature. Atmospheric concentrations of CO2 are continuing to increase at an unprecedented rate. This troubling trend is primarily driven by human activities, particularly the burning of fossil fuels and land use changes such as deforestation.