Some 400 million people depend on threatened coral reefs for their livelihoods, British scientists warn at UN meeting
As well as warming the atmosphere, carbon dioxide emissions from power stations and cars dissolve in the ocean, making it more acidic.
While it is driven by the same human activities as climate change, ocean acidification tends to have a lower profile, perhaps because the economic impacts are less well understood.
But the phenomenon causes nearly US$1 trillion worth of damage to coral reefs a year, in tandem with other human-caused environmental changes.
That is according to a report collated by British scientists from the work of thirty experts worldwide, to be launched at a UN biodiversity conference on Wednesday.
Murray Roberts, co-editor of the report and professor at Edinburgh’s Heriot-Watt University, said: “At the end of the day, the only way to deal with ocean acidification is to reduce CO2 emissions.
“But for this to happen people first need to be aware that ocean acidification is an important issue.”
Oceans cover two thirds of the planet and absorb much of the impact of greenhouse gas emissions, both through direct warming and acidification.
Yet they were largely absent from the high-level UN climate summit in New York last month, to the dismay of Global Ocean Commission co-chair David Miliband.
“There can be no solution to the climate challenge without a healthy ocean,” Miliband warned.
Today’s report brings together the latest modelling, laboratory and field studies in an attempt to focus attention on the issues.
It will be presented in Pyeongchang, South Korea, where scientists, policymakers and politicians are meeting to consider some of the global threats to biodiversity.
Ocean acidification has increased by around 26% since pre-industrial times, according to the report.
Marine fossil records show such trends have occurred before, but the speed at which it is happening is unprecedented in at least 66 million years.
And it is “nearly inevitable” that carbon dioxide emissions will further increase the ocean’s acidity, with a “deleterious” impact on wildlife.
Coral reefs are particularly sensitive to the changing pH level.
Some 400 million people depend on tropical coral reefs for their livelihoods, the report said, while cold-water corals in Europe support endangered sharks and commercially valuable fish species.
Sebastian Hennige, lead editor of the report, said research carried out from Edinburgh’s Heriot-Watt University had shown the vulnerability of cold-water corals.
“There is a risk that their habitat will literally dissolve away, since living corals grow on structures made by their dead ancestors,” said Hennige.
“These structures will be subject to chemical erosion over very large ocean areas if current trends continue.”