The September 2019 IPCC Special Report on the Ocean and Cryosphere in a Changing Climate, made it clear that the ocean is bearing the brunt of the crisis, resulting in acidification, heating and deoxygenation: the three factors present in every mass extinction event in Earth’s history.

In the meantime, One Ocean noted the role of the ocean in mitigating climate change, provisioning humankind through food, fresh water and oxygen and ameliorating extreme weather, is not currently recognised within the UNFCCC process.

Achieving the 1.5 C target under Paris Agreement "is vital and profoundly urgent as the timescales at work within the ocean mean that changes already put into its system – such as heating – will remain at work for hundreds of years."

Consequently, even with immediate action to curb temperature rise and cut CO2 emissions, ocean services to the planet could still be at risk.

Climate breakdown is impacting the entire ocean through heating, acidification and deoxygenation. The changes are unpredictable and there are continuous surprises for scientists, including the recent increase in marine heatwaves. Unless CO2 emissions are limited to prevent heating of more than 1.5C, we will see increasingly extreme and less predictable consequences for the ocean as tipping points are passed,

...said Professor Alex Rogers of the University of Oxford.

Action has to be taken to hold warming at 1.5 degrees Celsius. We need to see all states commit to more ambitious NDCs and go further to prevent the climate crisis from deepening and irreparably damaging the ocean upon which all life depends,

...added Rémi Parmentier, Secretary of The Because the Ocean Initiative.

Far more ambitious Nationally Determined Contributions (NDCs) are vital to hold heating at 1.5 C, but governments must also take action to remove the threats to the ocean which are within their immediate control, such as overfishing. Peggy Kalas of the High Seas Alliance noted:

The importance of protecting the biodiversity of the whole ocean cannot be overstated, it is essential in combating climate breakdown and maintaining the life support system that makes our planet habitable. Currently two thirds of the ocean, almost half the planet, falls outside the protection of law and that’s why it is so important that we secure a new, robust high seas treaty in 2020.

Overfishing, pollution, and destruction of habitats, ecosystems and biodiversity are all stressors that can be stopped in order to support the resilience of the ocean to withstand the climate crisis.

Between now and the end of 2020, the High Seas – the area beyond the national jurisdiction of any state, which makes up half the planet and two-thirds of the whole ocean – should be protected under international law.

The target for marine biodiversity should be to protect at least 30% of the ocean through implemented highly and fully protected areas, with the remaining 70% of the ocean sustainably managed.