One fifth of the world's coral has died

Bloomberg: One-fifth of the world’s corals have died and many remaining reefs may be lost by 2050 as carbon dioxide from cars and pollution-spewing industries make ocean water warmer and more acidic, the Global Coral Reef Monitoring Network said.

While natural disasters such as the earthquake that set off the Indian Ocean tsunami in 2004 killed some reefs instantly by forcing them out of the water, seas made warmer by heat-trapping CO2 gas is the biggest threat to corals, said the report from the International Union for Conservation of Nature. The Gland, Switzerland-based group is one of eight that manages the network.

The study was released as delegates from about 190 nations are meeting in Poland to lay the groundwork for a new treaty to fight global warming that is due to be signed a year from now in Copenhagen. The report shows that to sustain corals, CO2 emissions as well as damage from human activities must be kept to a minimum, said Clive Wilkinson, coordinator of the monitoring network.

“If nothing is done to substantially cut emissions, we could effectively lose coral reefs as we know them, with major coral extinctions,” Wilkinson said in the report. The fate of corals is crucial to the livelihoods of millions of coastal dwellers around the world. Reefs are worth about $30 billion a year to the global economy through tourism, fisheries and coastal protection, according to the Millennium Ecosystem Assessment, a United Nations-supervised study….

Acropora coral garden with giant clam. Raging Horn, Osprey Reef, Coral Sea, shot by Richard Ling, Wikimedia Commons via Flickr, under Creative Commons Attribution ShareAlike 2.0 License