L) Yet the mass extinction, however remote, that should be concentrating minds is that of mankind. It is not wise to dismiss it where CO2 emissions, the other great curse of the oceans, are concerned. In the long run, the seas are the great sink for nearly all carbon. They may be able to help avert some global warming – for instance, by providing storage for CO2, by providing energy through wave or tidal power, or by somehow taking carbon out of the atmosphere faster than at present. They will, however, continue to change and be changed as long as man continues to put so much carbon into the atmosphere.