Editorial: Need for an integrated view on oceans and climate

The oceans are hotter than ever. New records for marine heatwaves seem to be set more or less annually. Last summer, heatwaves in the Mediterranean Sea accompanied the extreme temperatures across Europe. In parallel, surface ocean pH has declined, corresponding to a 30 per cent increase in acidity. The acidification rate is about 100 times faster than experienced in 55 million years. As is the case for the warming, the process of ocean acidification continues.

Global warming, ocean acidification, and accompanying phenomena have severe effects on marine ecosystems. News reports on the effects of climate change on coral reefs, mangroves, distributions and populations of fish, etc. are sadly but rightfully commonplace. Continued reporting of such effects is extremely important – not least as some marine ecosystems, such as tropical coral reefs, are already facing severe consequences.

But the oceans are not only victims of climate change – they also play vital roles in the global carbon cycle and climate systems. The record warming and the increase in acidity are, in a way, symptoms of the capacity of the oceans to absorb excess heat and CO₂. Around 90 per cent of the heat from global warming has been stored in the oceans, while they have absorbed about 25-30 per cent of the CO₂ emissions.

The absorption of heat has weather-related consequences, such as escalating storms, hurricanes, cyclones and extreme rains. The absorption of CO₂ has to some extent mitigated the concentration of this gas in the atmosphere, but the potential is not limitless, nor is the buffering capacity of sea water towards escalating acidification.

Clearly, there is a great need for a continued process to integrate ocean issues and climate policies. Good news is that the UN Biodiversity Conference (COP15) identified among its targets the need to “minimize the impact of climate change and ocean acidification on biodiversity…”. Then there was the “Ocean and Climate Change Dialogue”, which was coordinated by the UNFCCC last year, following the so-called “Blue COP” in 2019. This dialogue addressed many of the interlinking issues previously mentioned and aimed to influence upcoming climate conferences.

However, the world is still waiting for a truly Blue UNFCCC-COP. Much of the focus of COP27 was on “loss and damage”, which contributed to less attention being given to other issues, including oceans. Without diminishing the importance of “loss and damage”, it is tragic that the underlying problem – i.e. climate change – was de-prioritised. World leaders must allocate efforts to all vital topics.
The One Ocean Hub1 were vaguely hopeful when summing up COP27: “…the Sharm El-Sheikh Implementation Plan represents slow progress towards integrating the ocean into the UN climate system, and towards implementing ocean-based climate action at a national level. Nevertheless, the discussions on the sidelines of the COP demonstrated more joined-up thinking about the ocean, climate change, biodiversity and human rights…”.

Another important event, the UN Ocean Conference, was held in Lisbon six months earlier. Despite a majority of government representatives highlighting the link between oceans and climate change in their speeches. There was a lack of ambition in the final declaration, as it didn’t include any “…detailed calls about scaling up ocean action under the Paris Agreement and the Glasgow Climate Pact…”, as the One Ocean Hub pointed out
Taken together, there is a build-up of expectations towards an integrated view on oceans and climate that translates into action under relevant treaties. Next up is the UNFCCC COP28. Let it not be wasted. The “sidelines” of COP27 must become “mainlines”.

Marko Reinikainen

¹ An international programme of sustainable research, funded through the Global Challenges Research Fund