Claims that coral reefs are doomed because human emissions are making the oceans more acidic have been exaggerated, a review of the science has found.
An “inherent bias” in scientific journals in favour of more calamitous predictions has excluded research showing that marine creatures are not damaged by ocean acidification, which is caused by the sea absorbing carbon dioxide from the atmosphere.
It has been dubbed the “evil twin of climate change” and hundreds of studies have claimed to show that it destroys coral reefs and other marine life by making it harder for them to develop shells or skeletons.
The review found that many studies had used flawed methods, subjecting marine creatures to sudden increases in carbon dioxide that would never be experienced in real life.
“In some cases it was levels far beyond what would ever be reached even if we burnt every molecule of carbon on the planet,” Howard Browman, the editor of ICES Journal of Marine Science, who oversaw the review, said. He added that this had distracted attention from more urgent threats to reefs such as agricultural pollution, overfishing and tourism.
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Dr Browman, who is also principal research scientist at the Norwegian Institute of Marine Research, found there had been huge increase in articles on ocean acidification in recent years, rising from five in 2005 to 600 last year.
He said that a handful of influential scientific journals and lobbying by international organisations had turned ocean acidification into a major issue.
“Such journals tend to publish doom and gloom stories . . . stated without equivocation,” he said. The bias in favour of doom-laden articles was partly the result of pressure on scientists to produce eye-catching work, he added.
“You won’t get a job unless you publish an article that is viewed as of significant importance to society. People often forget that scientists are people and have the same pressures on them and the same kind of human foibles. Some are driven by different things. They want to be prominent.”
Dr Browman invited scientists around the world to contribute studies on ocean acidification for a special edition of his journal. More than half of the 44 studies selected for publication found that raised levels of CO2had little or no impact on marine life, including crabs, limpets, sea urchins and sponges.
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Dr Browman said that the edition had demonstrated that there was “a body of work out there that people had difficulty publishing elsewhere” and that “not every study shows that Nemo is going to be doomed”, a reference to the reef-dwelling clownfish in the Disney film Finding Nemo.
The term ocean acidification was also a misnomer, he said, because it suggested that the oceans could become acidic instead of alkaline.
“The oceans will never become acid because there is such a huge buffering capacity in the oceans. We simply could never release enough CO2 into the atmosphere to cause the pH to go below 7 [the point in the pH scale at which a solution becomes acidic].
“If they had called it something else, such as ‘lower alkalinity’, it wouldn’t have been as catchy,” he said.
Dr Browman, a marine scientist for 35 years, said he was not saying that ocean acidification posed no threat, but that he believed that “a higher level of academic scepticism” should be applied to the topic.