In May 2013 the National Oceanic and Atmospheric Administration in the USA reported that the atmospheric concentration of CO2 at one of their recording stations topped 400 ppm for the first time. The media surrounding this event seems to have been very much based around the event itself with little comment on what it may mean. I find this moderately disappointing because we can be moderately confident of one thing – increased CO2 in the atmosphere means that more will dissolve into the ocean, which means an increase in ocean acidification (this is classical chemistry!).
Despite the recent efforts of some of the worlds best scientists, both here in Australia and overseas, we still have an incomplete picture of the likely biological and ecological effects of this ocean acidification. However, we can be fairly certain of two things:
1. Ocean acidification will have negative impacts on organisms which form calcareous structures like the shells of molluscs (see pictures below) and the skeletons of corals; and
2. We are becoming increasingly aware that the increase in CO2 as a resource will cause changes to systems that are dominated by primary producers like seagrass and algae (e.g. kelp), mostly for the worse (for a starting point you could look at my webpage, but contact me for more information if you want!).
Unfortunately, as we enter a time of uncertainty for science funding in Australia, we may not develop a complete understanding of the system-wide effects of ocean acidification until it’s too late.