Thousands of ocean species could be wiped because of rising acid levels in sea water, scientists have warned.
A major research project, by 500 of the world's leading acidification experts, suggests our oceans are souring at a faster rate than any time in the last 300 million years.
They blame the amount of carbon monoxide produced by humans and say that 30 per cent of ocean life, including coral and sea-snails, may not survive beyond the year 2100.
The scientists will present their findings at global climate talks in Poland next week.
French researcher Professor Jean-Pierre Gattuso, said: "My colleagues have not found in the geological record, rates of change that are faster than the ones we see today."
"In the Southern Ocean, we already see corrosion of pteropods which are like sea snails, in the ocean we see corrosion of the shell.
"[The snails] are eaten by fish, birds and whales, so if one element is going then there is a cascading impact on the whole food chain."
The cold waters of the Arctic and the Antarctic hold more CO2 than the rest of the world.
Researchers say that by 2020, ten percent of the Arctic will be too acidic for sea creatures.