The ocean absorbs around 30% of the annual emissions of anthropogenic CO2 to the atmosphere, helping to alleviate the impacts of climate change on the planet. The ecological costs to the ocean, however, are high, as the absorbed CO2 reacts with seawater and changes the acidity of the ocean, affecting life in the ocean as well as ocean services such as transport, fisheries and tourism. Observations from open ocean sources over the last 20 to 30 years have shown a clear trend of decreasing average pH, caused by increased concentrations of CO2 in seawater. In order to characterize the variability of ocean acidification, and to identify the drivers and impacts, a high temporal and spatial resolution of observations is crucial. The Sustainable Development Goal Target 14.3 specifically addresses ocean acidification and the associated Indicator calls for the measurement of marine acidity (pH).


Our work on Ocean Acidification

IOC is the custodian agency for the SDG Target 14.3 (ocean acidification) and its Indicator calling for "average marine acidity (pH) measured at agreed suite of representative sampling stations". As such, IOC is responsible for the development of the corresponding methodology, the collection of data towards the SDG Indicator from Member States and the submission of annual reports to the UN.

IOC is part the Global Ocean Acidification Observing Network (GOA-ON) whose goals include expanding ocean acidification observations, closing human and technology capacity gaps, connecting scientists regionally and globally, and informing about the impacts of ocean acidification.

IOC and the Scientific Committee on Oceanic Research (SCOR) sponsor the International Ocean Carbon Coordination Project (IOCCP), an ocean carbon monitoring and research programme.

IOC participates in the Ocean Acidification international Reference User Group (OA-iRUG) and is on the Advisory Board of the Ocean Acidification International Coordination Centre (OA-ICC) of the IAEA.

The IOC Sub-commission for the Western Pacific (WESTPAC) has organized training for scientists in the Western Pacific region so that experts and oceanographic institutions from the region and beyond can work together to improve monitoring of ocean acidification and to track changes in coral reef ecosystems. WESTPAC’s training efforts have focused on standardizing the approaches needed to monitor the ecological impacts of ocean acidification on coral reef ecosystems across all countries in the region


Useful links:

IOC Ocean Acidification Activities

Measure and Report Ocean Acidification - Sustainable Development Goal 14.3.1 Indicator Methodology (UN Oceans Conference Voluntary Commitment)

Global Ocean Acidification Observing Network (GOA-ON)