The oceans provide a much valuable service to society by absorbing about one fourth of the CO2 released by humans into the atmosphere, thereby moderating climate change. However, this generates considerable changes in the chemistry of seawater (“ocean acidification”), among which an increase in its acidity. As this century progresses, ocean acidification has the potential to affect a wide range of marine organisms, food webs, habitats and ecosystems that supply important goods and services to humankind. However, the socio-economic consequences of ocean acidification are still unknown and hampered by the poor knowledge of the impacts on an ecosystem scale. It is unfortunate that so much uncertainty remains because human society needs to get information with a relatively high degree of confidence before it decides to regulate its activities. Even with a high degree of certainty on future climate change and its likely impacts on society and economy, the reduction of CO2 emissions is proving extremely slow and difficult to implement. Ocean acidification and its impacts on marine ecosystems may well provide an additional reason for reducing CO2 emissions but the knowledge generated up to now is patchy and sometimes uncertain and conflicting, making it difficult for policymakers to move ocean acidification higher up on the agenda. It is a top priority for the current national and international projects to fill the gaps as soon as possible.
Jean-Pierre Gattuso, CNRS and Université Pierre et Marie Curie-Paris 6
This column expresses the personal opinion of the author