COP26 failed to address ocean acidification, but the law of the seas means states must protect the world’s oceans
In a new article on The Conversation, University of Canterbury’s Professor Karen Scott explains that international treatries require countries to protect marine environments by reducing their CO2 emissions.
With the exception of rising sea levels, climate change impacts on the oceans have been treated as a peripheral matter at global climate change negotiations. This marginalisation of the oceans largely continued at COP26.
But states, including New Zealand and Australia, nevertheless have an obligation to prevent and mitigate excess carbon dioxide (CO₂) from entering the ocean.
Almost four decades ago, 168 states signed up to the UN Convention on the Law of the Sea (UNCLOS). Under this treaty, they must address CO₂ in the oceans consistent with (but distinct from) their obligations under the climate regime.
Ocean acidification (OA) is caused by excess CO₂ in seawater. Atmospheric concentrations of CO₂ have now reached 414ppm (from about 280ppm in 1750) and the oceans are a major sink, having absorbed nearly half of all anthropogenic emissions since the beginning of the Industrial Revolution some two centuries ago.