BBC: The world's oceans are becoming acidic at an "unprecedented rate" and may be souring more rapidly than at any time in the past 300 million years.
In their strongest statement yet on this issue, scientists say acidification could increase by 170% by 2100.
They say that some 30% of ocean species are unlikely to survive in these conditions.
The researchers conclude that human emissions of CO2 are clearly to blame.
The study will be presented at global climate talks in Poland next week. ...