The acid truth about our oceans: experts urge action to limit ocean acidification

Ocean acidification can no longer remain on the periphery of the international debates on climate change and the environment and should be addressed by the UN Framework Convention on Climate Change and other global environmental conventions, urges IUCN and the International Ocean Acidification Reference User Group (RUG) at the climate change summit in Durban.

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In the run up to the United Nations Conference on Sustainable Development, which will take place in Rio de Janeiro in June next year (Rio+20), world experts from RUG call for decision makers to urgently address the critical issue of ocean acidification.

“The increasing amounts of carbon dioxide that we emit into the atmosphere every day are changing our oceans, steadily increasing their acidity, and dramatically affecting marine life,” says Professor Dan Laffoley Marine Vice Chair of IUCN’s World Commission on Protected Areas and Chair of RUG. “This may also have severe impacts on human life in the future. Only by reducing our CO2 emissions and enhancing the protection of oceans to strengthen their ability to recover, can we effectively address this issue. Policy makers in Durban, and in Rio in June next year, need to recognize this and take appropriate actions.”

Reducing greenhouse gas emissions into the atmosphere, particularly CO2, which is the main driver of climate change and the main cause of ocean acidification, is one of the goals of the UN Framework Convention on Climate Change. But the latest RUG publication calls for a broader strategy to reduce ocean acidification, alongside those tackling other threats to the marine environment such as overfishing and pollution.

According to the experts, although both climate change and ocean acidification are caused by excessive amounts of CO2 emissions, and so should be tackled together, not all approaches used to address the former will be effective in the fight against the latter.

"For example, ‘geoengineering' solutions, such as reflecting solar radiation, which are often suggested to deal with climate change, will not address the progressive acidification of the ocean," says Dr John Baxter of the Scottish Natural Heritage and Deputy Chair of the RUG. "Both climate change and acidification need to be taken into account when designing solutions to these challenges."

Each year, the ocean absorbs approximately 25% of all the CO2 we emit. Its acidity has increased by 30% since the beginning of the Industrial Revolution and acidification will continue at an unprecedented rate in the coming decades. This can have a negative impact on marine organisms, especially the 'calcifying’ ones such as shellfish, molluscs, coral reefs and various types of zooplankton and phytoplankton. Increasing ocean acidity requires them to use more energy to build their shells, which has potentially severe ecological consequences. If the current acidification rate continues, it could lead to extinctions of some species and impact others that feed on them.

“Through its ability to absorb large amounts of CO2, the ocean plays a crucial role in moderating the rate and severity of climate change”, says Dr Carol Turley from the Plymouth Marine Laboratory and the Knowledge Exchange Coordinator for the UK Ocean Acidification Research Programme, one of the partners of the Reference User Group. “But in many ways our ocean is also a victim of its own success, as this capacity jeopardizes its future health, its biodiversity and its ability to continue to provide us with food and sustainable economic development. Ocean acidification requires urgent and effective action now, before it’s too late. The obvious action is to reduce CO2 emissions to the atmosphere."

To view the publication click here.

For more information, or to set up interviews, please contact:
Ewa Magiera, IUCN Media Relations, m +41 79 856 76 26, e
Brian Thomson, IUCN Media Relations, m SA +27 (0)74 186 8665, m CH +41 (0)79 721 8326, e

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About the International Ocean Acidification Reference User Group (RUG)

The RUG was established in 2008 to support the work of the European Project on Ocean Acidification (EPOCA), and now supports complementary studies in Germany (BIOACID), the UK (the UK Ocean Acidification research programme, UKOA), the Mediterranean (Mediterranean Sea Acidification in a Changing Climate project and MRUG), with strong links in similar projects ? in the USA and the Australian ocean acidification RUG.

The International RUG draws together a wide range of end users to support the work of leading scientists on ocean acidification, to facilitate the rapid transfer of knowledge, and help the effective delivery of quality science.

Details of the four research programmes are given below:

European Union: In 2008 the European Commission funded the European Project on Ocean Acidification (EPOCA;, an initiative to investigate “Ocean acidification and its consequences” as a multinational effort that includes 32 laboratories located in ten European countries. This 4 year research project aims to monitor ocean acidification and its effects on marine organisms and ecosystems, to identify the risks of continued acidification, and to understand how these changes will affect the Earth system as a whole.

European Union: In 2011 the European Commission funded Mediterranean Sea Acidification in a Changing Climate (MedSeA; which assesses uncertainties, risks and thresholds to Mediterranean Sea acidification and warming at organism, ecosystem and economic scales and potential regional adaptation and mitigation strategies. MedSeA is funded for 3 years and involves 16 institutes from 10 countries mainly from the Mediterranean.

• Germany: The Biological Impacts of Ocean Acidification (BIOACID) programme involves 18 research institutes and is funded by the Federal Ministry of Education and Research (BMBF) for an initial 3-year period starting in September 2009. Its main focus is on the effects of ocean acidification on the marine biota at the sub-cellular to ecosystem level and their potential impacts on ecosystem services and biogeochemical feedbacks

• United Kingdom: Following an initial study (2004-2007): Implication for the Marine Environment of CO2 (IMCO2), a 5-year UK Ocean Acidification (UKOA) research programme ( is now underway involving over 120 researchers in 26 laboratories. UKOA is funded by the Natural Environment Research Council (NERC), the Department for Environment, Food and Rural Affairs (DEFRA) and the Department of Energy and Climate Change (DECC).


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