acidification." Watson-Wright added there were reasons be feel positive that oceans will feature highly in Rio. "As we are entering the negotiation phase of the declaration that will be adopted at Rio+20, there are encouraging signals that ocean acidification will be considered. In the zero -- draft declaration released on 10 January by the UN, the proposals put forward in the Blueprint Report have been included," she said. Comments (1) If high CO2 causes the ocean pH to drop, how do you lxpeain the Cretaceous, Paleocene, Eocene, and early Oligocene, when vast deposits of calcium carbonate were laid down? There must have been a lot of CO2 available to form all that carbonate rock, plus it was so warm for 200 million years that there were no icecaps nor glaciers. On would intuit that the high temperatures were due, at least in part, to high atmospheric CO2. But if the CO2 made the ocean acidic, how did all that carbonate rock form? Calcium carbonate is soluble in even weak acid. Do these environmentalists ever think through what they are saying?