Coral reefs 'will be gone by end of the century'

They will be the first entire ecosystem to be destroyed by human activity, says top UN scientist

A A A

Coral reefs are on course to become the first ecosystem that human activity will eliminate entirely from the Earth, a leading United Nations scientist claims. He says this event will occur before the end of the present century, which means that there are children already born who will live to see a world without coral.

Click HERE to upload graphic (192k jpg)

The claim is made in a book published tomorrow, which says coral reef ecosystems are very likely to disappear this century in what would be "a new first for mankind – the 'extinction' of an entire ecosystem". Its author, Professor Peter Sale, studied the Great Barrier Reef for 20 years at the University of Sydney. He currently leads a team at the United Nations University Institute for Water, Environment and Health.

The predicted decline is mainly down to climate change and ocean acidification, though local activities such as overfishing, pollution and coastal development have also harmed the reefs. The book, Our Dying Planet, published by University of California Press, contains further alarming predictions, such as the prospect that "we risk having no reefs that resemble those of today in as little as 30 or 40 more years".

"We're creating a situation where the organisms that make coral reefs are becoming so compromised by what we're doing that many of them are going to be extinct, and the others are going to be very, very rare," Professor Sale says. "Because of that, they aren't going to be able to do the construction which leads to the phenomenon we call a reef. We've wiped out a lot of species over the years. This will be the first time we've actually eliminated an entire ecosystem."

Coral reefs are important for the immense biodiversity of their ecosystems. They contain a quarter of all marine species, despite covering only 0.1 per cent of the world's oceans by area, and are more diverse even than the rainforests in terms of diversity per acre, or types of different phyla present.

Recent research into coral reefs' highly diverse and unique chemical composition has found many compounds useful to the medical industry, which could be lost if present trends persist. New means of tackling cancer developed from reef ecosystems have been announced in the past few months, including a radical new treatment for leukaemia derived from a reef-dwelling sponge. Another possible application of compounds found in coral as a powerful sunblock has also been mooted.

And coral reefs are of considerable economic value to humans, both as abundant fishing resources and – often more lucratively – as tourist destinations. About 850 million people live within 100km of a reef, of which some 275 million are likely to depend on the reef ecosystems for nutrition or livelihood. Fringing reefs can also help to protect low-lying islands and coastal regions from extreme weather, absorbing waves before they reach vulnerable populations.

Carbon emissions generated by human activity, especially our heavy use of fossils fuels, are the biggest cause of the anticipated rapid decline, impacting on coral reefs in two main ways. Climate change increases ocean surface temperatures, which have already risen by 0.67C in the past century. This puts corals under enormous stress and leads to coral bleaching, where the photosynthesising algae on which the reef-building creatures depend for energy disappear. Deprived of these for even a few weeks, the corals die.

On top of this comes ocean acidification. Roughly one-third of the extra carbon dioxide we put into the atmosphere is absorbed through the ocean surface, acidifying shallower waters. A more recently recognised problem in tropical reef systems, the imbalance created makes it harder for reef organisms to retrieve the minerals needed to build their carbonaceous skeletons. "If they can't build their skeletons – or they have to put a lot more energy into building them relative to all the other things they need to do, like reproduce – it has a detrimental effect on the coral reefs," says Paul Johnston of the University of Exeter, and founder of the UK's Greenpeace Research Laboratories.

An important caveat to the book's predictions is that the corals themselves – the tiny organisms largely responsible for creating reefs – may be lucky enough to survive the destruction, if past mass extinction episodes are anything to go by. "Although corals are ancient animals and have been around for hundreds of millions of years, there have been periods of reefs, and periods where there are no reefs," explains Mark Spalding, of the US-based environmental group Nature Conservancy, and the University of Cambridge. "When climatic conditions are right they build these fantastic structures, but when they're not they wait in the wings, in little refuges, as a rather obscure invertebrate."

The gaps between periods in which reefs are present have been long even in geological terms, described in the book as "multimillion-year pauses". And reef disappearance has tended to precede wider mass extinction events, offering an ominous "canary in the environmental coal mine" for the present day, according to the author. "People have been talking about current biodiversity loss as the Holocene mass extinction, meaning that the losses of species that are occurring now are in every way equivalent to the mass extinctions of the past," Professor Sale says. "I think there is every possibility that is what we are seeing."

About 20 per cent of global coral reefs have already been lost in the past few decades. Mass bleaching events leading to widespread coral death are a relatively recent phenomenon; though scientists have been studying coral reefs in earnest since the 1950s, mass bleaching was first observed only in 1983.

Dr Spalding, who witnessed the catastrophic 1998 mass bleaching in the Indian Ocean first-hand, says: "It was a shocking wake-up call for the world of science, and a shocking wake-up for me to be actually there as we watched literally 80 to 90 per cent of all the corals die on the reefs of the Seychelles and other islands in a few weeks." That single event destroyed 16 per cent of the world's coral.

But according to the book's author: "The 1998 bleaching was spectacular because it was so extensive and so conspicuous. But there have been mass bleachings that have been global since then: 2005 was bad; 2010 was bad. The visual appearance is not nearly as severe as it was in 1998, simply because there is less coral around."

These dramatic episodes coincide with unusual weather patterns such as El Niño, but are increasing in severity and frequency due to climate change. As such, tackling global warming is the most urgent solution advocated by the book. "If we can keep CO2 concentrations below 450 parts per million we would be able to save something resembling coral reefs," Professor Sale says. "They wouldn't be the coral reefs of the 1950s or 1960s, but they would be recognisably coral reefs, and they would function as reefs." The current atmospheric carbon dioxide concentration is about 390 parts per million, but few experts believe it will remain below 500 for long.

There are signs that local conservation efforts can make a difference. Alex Rogers, professor of conservation biology at Oxford University, says: "We know for certain that corals subject to low levels of stress are much more able to recover. So if you take away pressures like overfishing of coral reefs and pollution, this has profound effects on recovery. But what we're really doing is buying time for many of these ecosystems. If climate change continues at its current rate, they will be done for eventually."

Though not all scientists agree with the precise timescales set out by the book, the crisis is clear. "When you're talking about the destruct-ion of an entire ecosystem within one human generation, there might be some small differences in the details – it is a dramatic image and a dramatic statement," Professor Rogers says. "But the overall message we agree with. People are not taking on board the sheer speed of the changes we're seeing."

'Our Dying Planet' (University of California Press) will be published in North America tomorrow

Arts & Entertainment
Shaun Evans as Endeavour interviews a prisoner as he tries to get to the bottom of a police cover up
tvReview: Second series comes to close with startling tale of police corruption and child abuse
Arts & Entertainment
A stranger calls: Martin Freeman in ‘Fargo’
Review: New 10-part series brims with characters and stories

Arts & Entertainment
Schwarzenegger winning Mr. Universe 1969
arts + entsCan you guess the celebrity from these British Pathe News clips?
Sport
Raheem Sterling and Luis Suarez celebrate during Liverpool's game with Norwich
football Another hurdle is out of the way for Brendan Rodgers' side
VIDEO
Have you tried new the Independent Digital Edition iPad app?
Arts & Entertainment
The star of the sitcom ‘Miranda’ is hugely popular with mainstream audiences
TVMiranda Hart lined up for ‘Generation Game’ revival
News
Portrait of Queen Elizabeth-II by David Bailey which has been released to mark her 88th birthday
peoplePortrait released to mark monarch's 88th birthday
Life & Style
The writer, Gerda Saunders, with her mother, who also suffered with dementia before her death
healthGerda Saunders on the most formidable effect of her dementia
Sport
Manchester United manager David Moyes looks on during his side's defeat to Everton
footballBaines and Mirallas score against United as Everton keep alive hopes of a top-four finish
Sport
Tour de France 2014Sir Rodney Walker on organising the UK stages of this year’s race
Arts & Entertainment
Jessica Brown Findlay as Mary Yellan in ‘Jamaica Inn’
TVJessica Brown Findlay on playing the spirited heroine of Jamaica Inn
News
YouTube clocks up more than a billion users a month
mediaEuropean rival Dailymotion certainly thinks so
Arts & Entertainment
The original design with Charles' face clearly visible, which is on display around the capital
arts + ents The ad shows Prince Charles attired for his coronation in a crown and fur mantle with his mouth covered by a criss-cross of white duct tape
Arts & Entertainment
‘Self-Portrait Worshipping Christ’ (c943-57) by St Dunstan
books How British artists perfected the art of the self-portrait
Sport
Luis Suarez celebrates after scoring in Liverpool's 3-2 win over Norwich
Football Vine shows Suarez writhing in pain before launching counter attack
News
People White House officials refuse to make comment on 275,000 signatures that want Justin Bieber's US visa revoked
News
Sir Cliff Richard is to release his hundredth album at age 72
PEOPLE
Sport
Lukas Podolski celebrates one of his two goals in Arsenal's win over Hull
football
Arts & Entertainment
Quentin Tarantino, director
film
News
The speeding train nearly hit this US politican during a lecture on rail safety
news As the saying goes, you have to practice what you preach
Sport
Mercedes Formula One driver Lewis Hamilton of Britain (front) drives ahead of Red Bull Formula One driver Daniel Ricciardo of Australia during the Chinese F1 Grand Prix at the Shanghai International circuit
sport
Arts & Entertainment
Billie Jean King, who won the women’s Wimbledon title in 1967, when the first colour pictures were broadcast
tv
News
Snow has no plans to step back or reduce his workload
mediaIt's 25 years since Jon Snow first presented Channel 4 News, and his drive shows no sign of diminishing
Life & Style
food + drinkWhat’s not to like?
Have you tried new the Independent Digital Edition iPad app?
iJobs Job Widget
iJobs General

Geography Teacher

£130 - £140 per day: Randstad Education Ilford: Secondary Geography Teacher Lo...

Do you want to work in Education?

£55 - £70 per day: Randstad Education Cheshire: Are you a dynamic and energeti...

SEN Teaching Assistant

Negotiable: Randstad Education Group: SEN TAs, LSAs and Support Workers needed...

Private Client Senior Manager - Sheffield

£50000 - £60000 per annum: Pro-Recruitment Group: The Sheffield office of this...

Day In a Page

How I brokered a peace deal with Robert Mugabe: Roy Agyemang reveals the delicate diplomacy needed to get Zimbabwe’s President to sit down with the BBC

How I brokered a peace deal with Robert Mugabe

Roy Agyemang reveals the delicate diplomacy needed to get Zimbabwe’s President to sit down with the BBC
Video of British Muslims dancing to Pharrell Williams's hit Happy attacked as 'sinful'

British Muslims's Happy video attacked as 'sinful'

The four-minute clip by Honesty Policy has had more than 300,000 hits on YouTube
Church of England-raised Michael Williams describes the unexpected joys in learning about his family's Jewish faith

Michael Williams: Do as I do, not as I pray

Church of England-raised Williams describes the unexpected joys in learning about his family's Jewish faith
A History of the First World War in 100 moments: A visit to the Front Line by the Prime Minister's wife

A History of the First World War in 100 moments

A visit to the Front Line by the Prime Minister's wife
Comedian Jenny Collier: 'Sexism I experienced on stand-up circuit should be extinct'

Jenny Collier: 'Sexism on stand-up circuit should be extinct'

The comedian's appearance at a show on the eve of International Women's Day was cancelled because they had "too many women" on the bill
Cannes Film Festival: Ken Loach and Mike Leigh to fight it out for the Palme d'Or

Cannes Film Festival

Ken Loach and Mike Leigh to fight it out for the Palme d'Or
The concept album makes surprise top ten return with neolithic opus from Jethro Tull's Ian Anderson

The concept album makes surprise top ten return

Neolithic opus from Jethro Tull's Ian Anderson is unexpected success
Lichen is the surprise new ingredient on fine-dining menus, thanks to our love of Scandinavian and Indian cuisines

Lichen is surprise new ingredient on fine-dining menus

Emily Jupp discovers how it can give a unique, smoky flavour to our cooking
10 best baking books

10 best baking books

Planning a spot of baking this bank holiday weekend? From old favourites to new releases, here’s ten cookbooks for you
Jury still out on Manchester City boss Manuel Pellegrini

Jury still out on Pellegrini

Draw with Sunderland raises questions over Manchester City manager's ability to motivate and unify his players
Ben Stokes: 'Punching lockers isn't way forward'

Ben Stokes: 'Punching lockers isn't way forward'

The all-rounder has been hailed as future star after Ashes debut but incident in Caribbean added to doubts about discipline. Jon Culley meets a man looking to control his emotions
Mark Johnston: First £1 million jackpot spurs him on

Mark Johnston: First £1 million jackpot spurs him on

The most prize money ever at an All-Weather race day is up for grabs at Lingfield on Friday, and the record-breaking trainer tells Jon Freeman how times have changed
Ricky Gervais: 'People are waiting for me to fail. If you think it's awful, then just don't watch it'

Ricky Gervais: 'People are waiting for me to fail'

As the second series of his divisive sitcom 'Derek' hits screens, the comedian tells James Rampton why he'll never bow to the critics who habitually circle his work
Mad Men series 7, TV review: The suits are still sharp, but Don Draper has lost his edge

Mad Men returns for a final fling

The suits are still sharp, but Don Draper has lost his edge
Google finds a lift into space will never get off the ground as there is no material strong enough for a cable from Earth into orbit

Google finds a lift into space will never get off the ground

Technology giant’s scientists say there is no material strong enough for a cable from Earth into orbit