The Beacon

COP16: Targeting Ocean Acidification

Oceana marine scientist Ellycia Harrould Kolieb is at the COP16 climate negotiations in Cancun.

On Tuesday I spoke at a side event on ocean acidification hosted by IUCN. The panel covered the science, research activities and policy developments surrounding ocean acidification.

On this panel, I spoke about the scientific issues that will need to be addressed in order to effectively incorporate acidification into the UNFCCC process. These are discussions that will need to be informed at the policy level by scientific evidence, and at this stage there is still more work needed to clarify some of these issues on the scientific front.

Since ocean acidification is caused by the absorption of carbon dioxide from the atmosphere, the UNFCCC is the most appropriate body to house discussions around preventing rising ocean acidity. However, there are differences between climate change and ocean acidification, and as a result the UNFCCC will need to address these differences to effectively incorporate ocean acidification into its policies and mechanisms.

Establishing an effective indicator for ocean acidification that can be put alongside temperature is going to be one of the first issues that will need to be looked at. Currently the UNFCCC uses temperature as a target (2oC or 1.5 oC) that should not be surpassed if we are hoping to avoid extreme effects from climate change. Temperature therefore also acts as an indicator of how severe climate change is, and allows us to judge the success of our mitigation strategies.

The problem is that since ocean acidification is not driven by rising temperatures (unlike climate change), temperature will not act as an effective indicator for ocean acidification. So a new indicator will need to be set alongside temperature that will tell us how ocean acidification is progressing and allow us to gauge whether or not we are effective in mitigating it.

Both pH (which measures the change in acidity of ocean waters) and carbonate saturation state (the measurement of whether calcium carbonate structures will begin to dissolve) have been suggested as possible indicators, however more discussions need to be had to clarify which will be most effective.

Targets, both the level and type, will also need to be discussed in relation to ocean acidification. Thresholds for ocean acidification will need to be established, as will a safe stabilization level for atmospheric carbon dioxide. Current scientific evidence suggests that a stabilization of 450 ppm will be very dangerous for the oceans and possibly catastrophic to some marine systems, such as coral reefs. 350 ppm appears to be a safe level, as there will be some changes felt, however this level will prevent the worst effects of ocean acidification.

The UNFCCC currently doesn’t distinguish between the different greenhouse gases that cause climate change; they are all weighted in comparison to carbon dioxide, and a reduction in one is not preferred over reductions in the others. This is good for climate change, but it does not guarantee that ocean acidification will be effectively dealt with, as only carbon dioxide drives the global changes in ocean acidity.

In order to mitigate ocean acidification, the UNFCCC will need to work out separate stabilization targets for carbon dioxide and the other greenhouse gases.

These are two of the most pressing issues that will need to be addressed in order to effectively incorporate ocean acidification into the UNFCCC. Action needs to be taken soon, as ocean acidification is progressing at a rapid rate and will likely have catastrophic impacts throughout the oceans as well as on the humans that depend on them.

In order to find out more about the scientific and policy issues surrounding the UNFCCC and ocean acidification, please see our newly released white paper.

To view the video of Ellycia speaking at the side event on Ocean Acidification, click here.

Join us by taking action to stop ocean acidification!


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