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14/11/2013 10:24 GMT | Updated 23/01/2014 18:56 GMT

Climate Change: World's Oceans Becoming Acidic At An 'Unprecedented Rate'

Rene Frederick via Getty Images

The world's oceans are "pickling" as they become acidic at the fastest rate in 300m years, creating a grim outlook for global waters.

Shockingly, scientists have warned acidification could increase by 170% by 2100.

Some 30% of ocean species are unlikely to survive in these conditions, they say.

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In a report released Thursday, researchers say that carbon dioxide emissions from human activities such as fossil fuel burning are the primary cause of ocean acidification - with 24 million tonnes of CO2 being added to oceans every day.

The report is based on the findings from a September 2012 Symposium on the Ocean, at which 540 experts from 37 countries discussed research on ocean acidification.

They say the rate of change is "unprecedented," and warned that unless carbon dioxide emissions are reduced, marine ecosystems will be irreversibly damaged and the impact of climate change will be worsened.

The report says oceans currently act as a CO2 "sinkhole" absorbing approximately a quarter of emissions.

One of the report's authors is Daniela Schmidt, from the University of Bristol, told CNN: "This isn't a problem that is just going to go away. It's simple. The consequences are frightening."

"Within decades, large parts of the polar oceans will become corrosive to the unprotected shells of calcareous marine organisms," the report says, while in the tropics the growth of coral reefs may be hampered.

"People who rely on the ocean's ecosystem services are especially vulnerable and may need to adapt or cope with ocean acidification impacts within decades," it says. "Tropical coral reef loss will affect tourism, food security and shoreline protection for many of the world's poorest people."

"Very aggressive reductions in CO2 emissions are required to maintain a majority of tropical coral reefs in waters favorable for growth," the report says.

The effects are already visible, Prof Jean-Pierre Gattuso, from CNRS, the French national research agency told the BBC.

"In the Southern Ocean, we already see corrosion of pteropods which are like sea snails, in the ocean we see corrosion of the shell.

"They are a key component in the food chain, they are eaten by fish, birds and whales, so if one element is going then there is a cascading impact on the whole food chain."