Morgan - I don't think the question is "are oceans becoming more acidic", that's fairly well accepted.

The question is (or at least my question is), will acidification of oceans have a significant negative impact on their ability to absorb CO2? Has a decrease in CO2 absorption by the oceans been detected? If so, has it been quantified? All I've been able to find is that the increased acidification of the oceans "could" have an impact, but no hard numbers, or even an attempt to quantify it. Lots of work quantifying the acidification, but I haven't been able to find anything on CO2 absorption.

It is interesting to note that your last link contains a quote from Dr Carol Turley of the Plymouth Marine Laboratory.

"The oceans have already taken up about 50% of the CO2 that man has produced over the last 200 years and will continue to do so."

Doesn't sound like she's expecting the oceans to stop absorbing CO2 any time soon. If the oceans do not stop absorbing CO2, then it is next to impossible to reach that 2xCO2 level, or even that really scary 3xCO2 level, that are used as scenarios in GCMs.

Makes you start to wonder why they are publishing results from scenarios that can't be reached (due to limited carbon supplies). When do you think we can expect the 4xCO2 scenario to make it's appearance?