The new paper that was published in Science this week will, hopefully, be a wake up call that it's not just global warming that is of great concern, it's the changes in the oceans. When people talk about the ocean and CO2, mostly it's in terms of ocean acidification. However the changes we are causing to the oceans go way beyond changes in pH. It's not just shellfish and other pH sensitive species that are affected by the changes we are bringing about. The oceans are crucial to climate (think ENSO), to our food supply, and to biodiversity.
The paper was from a large international team of scientists led by Jean-Pierre Gattuso of the Observatoire Océanologique de Villefranche-sur-Mer. It concludes by summarising four critical messages - the main one being that we must immediately make substantial reductions to CO2 emissions (my emphasis):
- The ocean strongly influences the climate system and provides important services to humans.
- Impacts on key marine and coastal organisms, ecosystems, and services from anthropogenic CO2 emissions are already detectable, and several will face high risk of impacts well before 2100, even with the stringent CO2 emissions scenario (RCP2.6). These impacts are occurring across all latitudes and have become a global concern that spans the traditional north/south divide.
- The analysis shows that immediate and substantial reduction of CO2 emissions is required in order to prevent the massive and effectively irreversible impacts on ocean ecosystems and their services that are projected with emissions scenarios more severe than RCP2.6. Limiting emissions to below this level is necessary to meet UNFCCC's stated objectives. Management options that overlook CO2, such as solar radiation management and control of methane emission, will only minimize impacts of ocean warming and not those of ocean acidification.
- As CO2 increases, the protection, adaptation, and repair options for the ocean become fewer and less effective.