I agree that the acidification of oceans is a huge problem, but I wanted to explain there is nothing to be concerned about understanding the CO2/H2CO3 equilibrium. It's pretty straightforward and well predictable (Ocean acidification due to increasing atmospheric carbon dioxide). What we don't fully know is how it will affect ecologic systems, but that goes for all pollutants.
Quote:it reacts with the CaCO3 of shells, corals etc.Not directly. The only reason that the CaCO3 from corals and such doesn't dissolve is because sea water is already saturated with it. Bringing more CO2 into the water will bind some of the dissolved CaCO3, which causes the concentration to drop. That will make corals dissolve. Apart from this, there are certainly more dangers for coral (temperature, sea level, etc), but that's because it's such a highly specialized and balanced ecological system, which makes it vulnerable to changing circumstances.