great-barrier-reefHe is seen as one of Britain’s iconic figures: Sir David Attenborough has graced millions of television screens from many a different part of the world to inform viewers of the beauty and plight of the natural world.

Will anyone listen to his latest warning? His message is not new, we have heard it before, but it’s certainly more urgent than before. And he has been joined by other eminent scientists to warn of the dangers facing coral reefs.

We knew that coral reefs were in trouble, but not this much trouble. The world’s coral reefs are in danger of dying out in the next 20 years unless the world drastically cuts carbon emissions, a coalition of scientists led by Sir David has warned.

The scientists gathered at the Royal Society in London yesterday to call for tougher targets for the world to cut carbon emissions. Sir David, who co-chaired the meeting, said that the collapse of coral reefs meant the death of marine ecosystems.

“We must do all that is necessary to protect the key components of the life of our planet as the consequences of decisions made now will likely be forever as far as humanity is concerned,” he said.

About a third of CO2 emissions are absorbed by open water. As oceans absorb CO2, they become more acidic, making it impossible for coral reefs like the Great Barrier Reef in Australia to survive.  They also become prone to bleaching as the waters warm.

Sir David was joined by Alex Rogers, from the Zoological Society of London and scientific director of the International Programme on the State of the Oceans, who warned that reefs were safe at CO2 levels of 350 parts per million, whereas we are now at 387ppm today.

On current trends, we will reach 450 ppm in the next 20 years if the world continues to burn fossil fuels at the current rate. Once that figure is reached, the ocean will become too acidic for corals to survive.

“The kitchen is on fire and it’s spreading round the house”, says Alex Rogers. “If we act quickly and decisively we may be able to put it out before the damage becomes irreversible. Essentially coral reefs are on death row and Copenhagen is one of the last opportunities for a reprieve,” he said.

Charlie Veron, former chief scientist of the Australian Institute of Marine Science, is another scientist warning of the dangers of inaction. “There is no way out, no loopholes. The Great Barrier Reef will be over within 20 years or so.”

If this happens it would be the world’s first global ecosystem to collapse.

And its going to happen in your lifetime.