Ocean acidification is poorly governed

By: Marko Reinikainen

Ocean acidification (OA) occurs as the result of increased atmospheric CO₂ which is taken up by the oceans.  About 30% of the CO₂ that has been emitted to the atmosphere because of human activity has ended up in waterbodies. Reactions between CO₂ and water eventually result in a higher concentration of hydrogen ions – i.e. lowered pH – in the oceans. Organisms in the oceans are adapted to the pH conditions that prevailed in the seas prior to this human-driven acidification process. Calcifying organisms in particular are sensitive to acidification, but the physiology of many other organisms can be affected as well, as can the complex ecological interactions between organisms. In a global setting, ongoing and projected effects of OA have been extensively described in several IPCC reports and their summaries for policy makers (e.g. IPCC, 20181, 20192).

It is obvious that OA “is a global problem with profoundly negative environmental, social and economic consequences”, as stated in a recent review by Galdies and co-authors3. This review specifically focuses on the governance framework relating to OA, particularly in Europe. At the global kevel, OA is included in the Sustainable Development Goals (SDGs) of the United Nations. It is specifically mentioned in Life below the Water SDG, and target 14.3 says to “reduce acidification”. In Europe, the European Environment Agency included OA in Europe’s “10 messages for 2010”.

But here comes the surprising part: Despite the inclusion of OA in such overarching policy documents, “EU-wide actions remain still incomprehensible and uncoordinated”, according to the review. Furthermore, and as evidenced by the review’s analysis covering 90 (!) legislative documents from 17 European countries, most countries make little reference to OA in their legislative framework. The most noteworthy exception is Norway, with its reportedly strong framework to combat OA. Some other countries, including Ireland, France, Spain and the UK, have some level of reference to OA, allowing them to address mitigation e.g. through sectoral policies and/or national strategies, yet with a lot of room for improvement.

Among the EU-level policy instruments that could be used as a framework for national policies to mitigate OA, the review pointed out that “…national policies rarely emphasised the overarching element of the Marine Strategy Framework Directive (MSFD)”. This is interesting, as the MSFD could guide EU member states to a more coordinated view on marine protection in general, and specifically also regarding OA, in order to reach Good Environmental Status (GES). It is noteworthy, however, that the MSFD does not include monitoring descriptors that concern OA specifically.

Climate change as a topic is included in EU-wide steering documents and there are hopes for significant upscaling of efforts to tackle climate change, for example through the European Green Deal and the European Climate Law proposed by the EU Commission. Similarly, although a lot needs to be done, some countries have national climate plans and other frameworks for climate policies. However, measures specifically designed to meet the challenge of OA are, as has been described, largely lacking.

This is not a trivial issue. Even if the abatement of climate change and the abatement of OA both require the mitigation of CO₂, the effects of temperature rise (and associated effects) and acidification are not the same. (Although they do occur concurrently and there can be interactions.) As stated in the review: “The problems associated with and the solutions needed to address OA are unique and cannot be bundled together with traditional climate change responses and measures”.

The review particularly mentions Marine Protected Areas (MPAs) as one of the tools that could be used and designed to tackle challenges associated with OA. MPAs that are properly assigned could help to ensure refugia, build ecosystem resilience, and promote the regeneration of threatened ecosystems.

On a positive note, the review highlights a number of pan-European research initiatives that have promoted the understanding of OA in European waters. These include, for instance, MEDSEA (for the Mediterranean Sea), VECTORS (with emphasis on biodiversity, fisheries, and aquaculture), MEESE (climate change effects in the Mediterranean Sea, the Atlantic Ocean, and the Baltic Sea). Additionally, the German project BIOACID focused especially on the biological effects of OA. Other projects, such as ATLANTOS have focused on ocean observations, as does COPERNICUS. To the list can also be added research infrastructures for experimental work, such as AQUACOSM and AQUACOSM-plus4, which provide facilities for large-scale experiments on a number of environmental topics, including OA.

The review concludes with a number of recommendations to policy makers regarding OA in European waters. These include continued OA-focused research and a European ocean resilience programme, transnational marine corridors, improved coordinated European-level governance and national reporting (with reference to GES and the MSFD) that takes into account OA, and awareness raising both among policy makers and the general public.

Marko Reinikainen

1. https://www.ipcc.ch/sr15/chapter/spm/

2. https://www.ipcc.ch/srocc/chapter/summary-for-policymakers/

3. Galdies, C. et al. 2020. European policies and legislation targeting ocean acidification in European waters – Current state. Marine Policy 118.

4. https://www.aquacosm.eu/

In this issue


The clock is ticking to achieve the 1.5°C goal of the Paris Agreement. To be clear right from the start: this goal deserves every effort that mankind can pull off. In the name of realism, this is the goal we must focus on now, given the current level of progress in reducing greenhouse gases. However, damage to marine ecosystems will not be avoided even if we reach this goal1. In fact, damage already occurs at current levels of warming, as evidenced by the bleaching of coral reefs2. This may be an inconvenient truth when our current goal is 1.5°C.

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