Reefs Could Perish by End of Century, Experts Warn
Date: 07-Jul-09
Country: UK
Author: Michael Kahn
Reefs Could Perish by End of Century, Experts Warn Photo: Ove Hoegh-Guldberg
Corals are seen at the Great Barrier Reef in this January
2002 handout photo.
Photo: Ove Hoegh-Guldberg
LONDON - Increasingly acidic oceans and warming water temperatures due to
carbon dioxide emissions could kill off the world's ocean reefs by the end
of this century, scientists warned on Monday.
The experts told a meeting in London the predicted pace of emissions means a
level of 450 parts per million of carbon dioxide (CO2) in the atmosphere
will be reached by 2050, putting corals on a path to extinction in the
following decades.
The two dozen coral reef specialists and climate change exerts represented
universities, government research offices and the Intergovernmental Panel on
Climate Change.
"The kitchen is on fire and it's spreading around the house," Alex Rogers of
the Zoological Society of London and the International Program on the State
of the Ocean, said in a statement.
"If we act quickly and decisively we may be able to put it out before the
damage becomes irreversible."
Oceans absorb large amounts of CO2 emitted by the burning of fossil fuels.
But scientists say the oceans are acidifying as they absorb more carbon,
disrupting the process of calcification used by sea creatures to build
shells as well as coral reefs.
Researchers around the world have been urging governments to take more
account of such threats to the oceans in a new U.N. treaty on fighting
global warming due to be agreed in Copenhagen in December.
Coral reefs -- delicate undersea structures resembling rocky gardens made by
tiny animals called coral polyps -- are important nurseries and shelters for
fish and other sea life.
They also protect coastlines, provide a critical source of food for millions
of people, attract tourists and are potential storehouse of medicines for
cancer and other diseases.
PATH TO MAJOR DEGRADATION
"If CO2 is allowed to reach 450 ppm, as is currently widely regarded as
being the most optimistic threshold target for world leaders to agree at
Copenhagen, we will have put the world's reefs on a path to major
degradation and ultimate extinction," John Veron, the former chief scientist
of the Australian Institute of Marine Science, told the meeting.
"Such a catastrophe poses a dire threat to the future wellbeing of all
humanity."
The scientists agreed that governments should strive for a level of 320
parts per million of carbon dioxide, saying 360 was a breaking point for
reefs to survive.
At the current level of 387 parts per million of carbon dioxide, reefs are
in serious decline, they said. This will have a future knock-effect that
threatens other marine and coastal ecosystems.
Coral covers about 400,000 square km of tropical ocean floor, but needs
sustained sunlight, warmer waters and high levels of carbonate to flourish.
The biggest is the Great Barrier Reef, a collection of 2,900 reefs along
2,100 km of Australia's north east coast in a marine park the size of
Germany.
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