Share & Connect
According to a study conducted by an international team of researchers, the rate at which the oceans are currently becoming more acidic has increased due to carbon emissions from humans.
Oceanic acidification is nothing new; oceans have been naturally acidified in the past, notably, as scientists learned, several times in the last 300 million years.
During the process of acidification, the oceans moderately draw excess carbon from the atmosphere. The carbon then reacts with the seawater to create carbonic acid, which causes most marine life to die off. Over time, the carbon acid is neutralized to form fossils of dead organisms.
“We know that life during past ocean acidification events was not wiped out—new species evolved to replace those that died off,” Bärbel Hönisch, a paleoceanographer at Columbia University’s Lamont-Doherty Earth Observatory, states in a press release from the Earth Institute at Columbia University. “But if industrial carbon emissions continue at the current pace, we may lose organisms we care about—coral reefs, oysters, salmon.”
Due to the rate at which carbon is entering the atmosphere, oceans are forced to draw it in more quickly and, therefore, are unable to deal with the excess.
Based on their studies, researchers discovered that acidification causes mass extinctions of marine life and disrupts ecosystems. In the 1990s, scientists found a layer of mud between two beds of carbonated fossil beds (the mud was created from dissolved fossils) from the Paleocene–Eocene Thermal Maximum (PETM) 56 million years ago.
They learned that in a span of 5,000 years, concentrations of atmospheric carbon doubled, and that the global temperature increased by 6º C (43º F), and the ocean pH dropped by 0.45, indicating that the acidity level rose.
Past research has revealed two other definite past occurrences of rapid seawater acidification, caused by massive volcanism. The first occurred in the Permian Period, 252 million years ago. In the vicinity of present-day Russia, immense amounts of carbon spewed from volcanic eruptions.
A staggering 96% of marine life went extinct. Researchers found dead zones around Russia’s coast and discovered that they only contain organisms able to withstand the high levels of carbon. The second occurrence took place 201 million years ago, during the Triassic period. A likewise percentage of species became extinct. In addition, the coral reefs were destroyed.
Numerous studies of oceans and the correlation of rising acidity levels and diminishing marine life are being conducted around the globe. For example, as stated by an article in the journal Nature, one study of the coral reefs at Papa New Guinea shows that the pH dropped 7.8 (a lot higher than the 0.48 stated before, as one can see), and so has coral reef diversity.
Christopher Langdon, a biological oceanographer at the University of Miami who co-authored the study on Papua New Guinea reefs, says “These studies give you a sense of the timing involved in past ocean acidification events—they did not happen quickly.”
Despite the present evidence of the build-up of carbon emissions and the detriments it has caused, decades would have to pass before the acidification would truly have to show its effects.
“Considering the effects we detect through fossil records,” Patrizia Ziveri, researcher at ICTA tells Universitat Autònoma de Barcelona, “there is no doubt that we must tackle the problem at its roots as soon as possible, adopting measures to immediately reduce our CO2 emissions into the atmosphere.”
A number of the researchers involved with the original studies are from the Institute of Environmental Science and Technology (ICTA) of Universitat Autònoma de Barcelona (UAB), the Spanish National Research Council (CSIC), and the Catalan Institute for Research and Advanced Studies (ICREA).