Organised by the Zoological Society and chaired by Sir David Attenborough, the meeting painted a sombre picture of what lies in store for corals around the globe – probable near-destruction by 2050, if current trends in the world’s carbon emissions continue.
Charlie Veron, formerly Chief Scientist of the Australian Institute of Marine Science, said: “There is no way out, no loopholes. The Great Barrier Reef will be over within 20 years or so.”
Attenborough commented: “Coral reef is the canary in the cage as far as the oceans of the world are concerned. They are the places where the damage is most easily and perhaps most quickly seen. They are a barometer of a malaise which is afflicting the ocean at large in which it is more difficult for us to see what is happening.”
Reflecting the special pleasures afforded to scuba divers who explore such areas, he added: “Anybody who has had the privilege of diving along a coral reef will have seen the natural world at its most glorious and its most diverse and most beautiful, and anybody who has done that would be appalled at the thought there was going to be damage, that the reefs should die and be covered with brown slime and turn to a gravel pit.”
Dr Alex Rogers, of the International Programme on the State of the Ocean, said: “Children born now could be the last generation to experience coral reefs as we know them.”
As a result of increasing carbon dioxide in the atmosphere, acidity levels in the sea rise, damaging coral. In addition, more heat is trapped within the atmosphere, with the knock-on effect of warmer seas and the “bleaching” of corals, which are highly sensitive to temperature change.
Carbon dioxide levels are thought to have changed from around 280 parts per million at the start of the industrial revolution to about 387ppm today. Under current international agreement, it has been proposed to limit levels to 450ppm – even though great damage has already been done at lower levels.
In a joint statement, scientists at the Royal Society meeting said: “Proposals to limit CO2 levels to 450ppm will not prevent the catastrophic loss of coral reefs from the combined effects of climate change and ocean acidification.
“To ensure long-term viability of coral reefs, atmospheric carbon dioxide level must be reduced significantly below 350ppm.” This, they added, could only be achieved by “the active removal of CO2 from the atmosphere”.