Coral reefs, as they existed half a century ago, will likely disappear from Earth even if climate change talks in December are "wildly successful", a distinguished professor and marine ecologist has warned.
The future of the planet’s coral reefs is looking bleaker than ever, Professor Peter F Sale, University of Windsor in Canada, said, as he presented his analysis at the largest annual geochemistry conference worldwide this week.
Prof Sale told the Goldschmidt 2015 conference in Prague that he predicted a post-apocalyptic future of “algal-dominated, rubble-strewn, slowly eroding limestone benches".
“We have lost 90 per cent of our commercial fish biomass since the 1940s … Either we agree limits, which means the end of the 'high seas', or we let large parts of the seas die.”
"This is now serious," he added. "I find it very unlikely that coral reefs as I knew them in the mid-1960s will still be found anywhere on this planet by midcentury."
Coral bleaching turns coral pale and white Photo: AP
An estimated 70 per cent of the world's reefs already threatened or destroyed, according to the US coral reef task force.
Prof Sale’s speech targets the insufficiency of the forthcoming Paris COP 21 – a climate change summit whose conservational bedrock is founded on a pledge to cap warming at 2C (35F).
According to Prof Sale, "even if Paris is wildly successful, and a treaty is struck, ocean warming and ocean acidification are going to continue beyond the end of this century".
The scientific community is year by year becoming more concerned about the viability of protecting these ecosystems – which support 33 per cent of marine fish species – in the face of threats brought about by global warming.
Marine scientists such as Prof Sale believe a more forceful and decisive response is needed to salvage the reefs. "We have got to lower our emissions of CO2 aggressively," the professor told the Telegraph.
The COP 21 target of reducing emissions to the extent that warming will total 2C (35F) since preindustrial times (the Copenhagen target) is too high a target to permit coral reefs to persist, he warned.
"I and a number of other ecologists argue for CO2 = 350 ppm in the atmosphere – that is where it was in 1980s, and that level will lead to a total of one degree of warming from per-industrial times."
However the problem is not limited to global warming; there are in fact several other “insults” that threaten the biodiversity of the oceans.
“Overfishing, pollution are the main ones … Overfishing is a problem worldwide and has numerous effects beyond simply lowering numbers of particular species of fish. Pollution comes in many forms, each with different effects – heavy metals, nutrients, plastics, etc”
According to Prof Sale the world's response should be twofold: firstly to implement “more aggressive emissions reduction” and secondly “to get serious about managing the other impacts on coral reefs”.
The latter needs to happen to create a buffer zone until the effects of reducing emissions can take effect. “If we stopped emitting CO2 entirely tomorrow, it would be the end of the century before the effects of CO2 on warming would cease growing,” he said.
"The sooner we get to managing reefs well, the better condition they will be in, and therefore better able to cope with the warming. We can act quickly on the local impacts to give them breathing space while we work hard at building global agreement and bring down CO2 emissions.”
“There is good evidence that the extent of coral cover on the Great Barrier Reef and also in the Caribbean is about 50 per cent less than it was in the early to mid 70s," he added.
Prof Sale is not alone in his fears. "The extreme gravity of the current predicament is now widely acknowledged by reef and climate scientists," Prof John Vernon, coral expert and former chief scientist of the Australian Institute of Marine Science, said.
"Only drastic action starting now will prevent wholesale destruction of reefs and other similarly affected ecosystems."