Fifth of corals dead: only emission cuts can save the rest, says the International Union for Conservation of Nature (IUCN). The world has lost 19% of its coral reefs, according to the 2008 global update of the world’s reef status.

The Global Reefs Status Report 2008, released by the Global Coral Reef Monitoring Network, shows that if current trends in carbon dioxide emissions continue, many of the remaining reefs may be lost within the next 20 to 40 years.

Climate change is considered to be the biggest threat to coral reefs at present. The main climate threats, such as increasing sea surface temperatures and seawater acidification, are being made worse by overfishing, pollution and invasive species.

“If nothing changes, we are looking at a doubling of atmospheric carbon dioxide in less than 50 years,” says Carl Gustaf Lundin, Head of the IUCN Global Marine Programme, one of the organizations behind the Global Coral Reef Monitoring Network. “As this carbon is absorbed, the oceans will become more acidic, which is seriously damaging a wide range of marine life from corals to plankton communities and from lobsters to seagrasses.”

At present, 45 % of the world’s reefs are healthy. A possible hopeful sign is the ability of some corals to recover after major bleaching events, caused by warming waters, and to adapt to climate change threats. However, the report shows that, globally, the downward trend of recent years has not been reversed. Major threats in the last four years, including the Indian Ocean tsunami, more instances of bleaching, coral diseases and human pressures, have slowed or reversed the recovery made by some coral reefs since the 1998 mass bleaching.

“The report details the strong scientific consensus that climate change must be limited to the absolute minimum. If nothing is done to substantially cut emissions, we could effectively lose coral reefs as we know them, with major coral extinctions,” says Clive Wilkinson, Coordinator of the Global Coral Reef Monitoring Network.

Visit: http://www. iucn. org/

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