
Australia’s Great Barrier Reef seems indestructible from afar: its 2,600-kilometer-long clusters of corals are even visible from outer space.
But on closer examination, the story loses some of its beauty. The reef -- along with the multi-billion dollar tourist industry it supports -- could be extinct by 2050.
That is what some scientists are warning will happen if nothing is done to halt the impact of human-induced climate change.
Rising levels of carbon dioxide in the atmosphere are causing oceans to warm, they argue, bleaching the reef’s corals to death.
“Most coral reefs have been seriously diminished already,” says Charlie Veron, former chief scientist of the Australian Institute of Marine Science and author of the three-volume, "Corals of the World".
“Today's children are almost certain to see the Great Barrier Reef trashed within their lifetime.”
Coral bleaching occurs when corals, stressed by warming water, expel the symbiotic algae, which provide necessary nutrients. As a result, they turn colorless and their calcium skeletons get exposed. Unless the water cools, death is not far behind.
Bleaching has been observed on the Great Barrier Reef since 1982, with severe “bleaching events” occurring during the El Niño of 1997-98 and later in 2002 and 2006. During the 2002 episode, it was reported that bleaching affected more than 50 percent of the reefs, with five percent permanently damaged.
“As time goes on and carbon dioxide increases, the likelihood of mass bleaching goes ever higher,” says Veron. “There is no rate as such, just an ever-increasing probability.”
more (with a fantastic photo gallery)