The Oceans are our largest natural sink for CO2. They absorb excess carbon dioxide from our atmosphere, but the oceans become more polluted as they absorb more CO2. It’s like a bioaccumulating toxin. CO2 is the mercury of our ocean’s water. The CO2 pollutes our oceans just like it pollutes our skies. Ocean acidity is rising and has already begun to rise beyond evolutionary constraints in some areas. Some ocean organisms can no longer be found where they have always been found because the ocean has become too acidic for them to survive. In a hundred years the oceans are expected to be 0.4 pH points lower than today. This is an astonishing 2 1/2 times more acidic than today. And this would be the good news. The European Science Foundations says that the literature shows an ocean tipping point at around 0.2 pH units more acidic than today. This level could be reached in 30 years. What does this mean? First, the oceans would absorb a tremendous amount LESS CO2 (the more acidic the oceans become the less they CO2 they can absorb). This is one of the big positive feedbacks that scientists worry about that is NOT included in the models. Second, there would likely be a mass extinction on the order of what happened in our oceans 55 million years ago when a lot of methane hydrates melted and cause significant global warming. Third, primary productivity in the oceans would crash. Primary productivity is the plankton and algae and such – the masses of single celled and few celled plants species that create oxygen. They are responsible for about half of the oxygen on our planet. If they go extinct we have a new problem.