CLIMATE CHANGE: Eye on the oceans

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Hundreds of millions depend on fishing for food and income Photo: Sudhanshu Goyal/Flickr

The tide seems to be finally turning for the oceans. After years of neglect, there is a growing focus on the health of the oceans, which helps sustain life on earth, particularly in light of the impact of rising levels of carbon dioxide (CO2) and higher temperatures.

Higher CO2 levels are causing the oceans to acidify at rates not seen in the last 20 million years, says Wendy Watson-Wright, assistant director-general and executive secretary of the Intergovernmental Oceanographic Commission of the UN Educational, Scientific and Cultural Organization (UNESCO-IOC).

Several UN agencies led by UNESCO-IOC have developed a Blueprint for Ocean and Coastal Sustainability, to highlight the role of oceans in sustaining life. They offer suggestions ahead of the UN Conference on Sustainable Development (UNCSD, or Rio+20).

The oceans not only supply the oxygen in every second breath we take, but also absorb at least 33 percent of the CO2 human beings produce. The oceans have already absorbed more than 80 percent of the heat added to the climate system over the past 200 years, says the International Programme on the State of the Ocean.

As CO2 dissolves in seawater, the pH (indicator for acidity and basicity of an aqueous solution) of the water decreases – a process known as “acidification” (a lower pH value indicates an increase in acidity).

This can reduce the availability of calcium for plankton and shelled species, threatening their survival. This in turn could affect the entire ecosystem, as much of the marine food chain depends on these organisms for food.

Acidification impact


Studies on ocean acidification’s potential impact on marine life and ecosytems have been presented regularly at side events during UN climate talks, but have never made it to the main negotiations, even though such talks frequently mention the impact of high CO2 on sea-level rise.

Mean ocean pH has decreased (which means the acidity in water has increased) by 30 percent since 1751 and if we continue to emit CO2 at the same rate, the pH could decrease by a further 150-200 percent by 2100, says a new book, Valuing the Ocean, by the Stockholm Environment Institute.

“This rate of change is around 10 times faster than that caused by any other event experienced by the ocean in the last 65 million years,” it says.

Yet only one percent of the oceans are protected, according to UNESCO-IOC.

Proposals

The Blueprint calls for the creation of a global “blue carbon market” similar to the proposal that led to Reducing Emissions from Deforestation and Degradation in Developing Countries (REDD), a mechanism within the UN Framework Convention on Climate Change (UNFCCC) to generate funds for the protection and conservation of forests.

In 2009, over 80 percent of the world’s fish catch was consumed by human beings, providing 4.2 billion people with more than 15 percent of their average per capita intake of animal protein, says the Blueprint. That year, fishing and aquaculture provided full or part time jobs for about 180 million people, supporting the livelihoods of over half a billion people.

The paper calls for the launch of a global inter-disciplinary programme on ocean acidification risk assessment. “The goal is to provide global, regional, and national forecasts and to identify `point of no return’ tipping points where acidification could lead to marine ecosystem collapse.”

It calls for support for small island states which are heavily dependent on the ocean – to help them use and manage marine resources sustainably.

The Blueprint also urges UNFCCC to include the impact of CO2 on the oceans in their deliberations; calls for stronger governance of the high seas; and the promotion of responsible fishing and waste disposal.

Pollution – especially that caused by fertilizer run-off, sewage and industrial waste – causes hypoxia, a reduction of the content of dissolved oxygen which makes life unsustainable in many parts of the ocean. There are now over 500 known hypoxic “dead zones” in the world’s oceans.

These problems were highlighted at UNCSD meetings in Rio (1992) and Johannesburg (2002). However, pledges to restore fish stocks to sustainable levels by 2015, and commitments to create networks of protected marine areas by 2012, have not got very far, say UN agencies.

Watson-Wright says she is hopeful, as the daft declaration released on 10 January by the UN, includes the proposals set out in the Blueprint.

UNESCO-IOC has also announced the launch of a Surface Ocean CO2 Atlas (SOCAT), which provides a 40-year record of CO2 accumulation in the surface ocean. The dataset was assembled by a team of over 100 scientists from around the world, coordinated by various universities and research centres.

Source: IRIN News - 5 April 2012


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