The Great Barrier Reef: a catastrophe laid bare

Australians are being wooed by politicians for an upcoming federal election, most of whom support policies that will guarantee the reef’s destruction.

This is the story of the impending death of the world’s largest living structure – whose hand it is dying by, who is staging a cover-up, and how it could be saved.

Murder on the reef

Let’s be completely clear. This is no natural death. And there’s no question about who is to blame.

Although bleaching has probably always happened in small patches here and there during unusually warm and calm weather, it used to be extremely rare. The first recorded bleaching was in 1911 on Bird Key Reef in the Florida Keys. It happened during a period of calm, hot weather.

Something similar was reported on the Great Barrier Reef in 1929.

Then there was not much to speak of for decades. There were a smattering of reports – maybe two or three over the next half century – until the year 1979.

That year, everything changed. A new phenomenon of “mass bleaching” was seen for the first time, where bleaching would smash large regions, rather than just isolated stretches of coral. In 1979 widespread bleaching was seen stretching throughout the Caribbean and the Florida Keys.

And from then there was no turning back. Every year since then, bleaching has been reported somewhere in the world, often on a regional scale. Something that had rarely been seen before was being seen literally every year.

Then it was time to go global. Coral reefs right around the world experienced bleaching during the first extreme El Niño recorded in 1982 and 1983.

El Niño is a splurge of warm water that spreads across the Pacific Ocean on irregular intervals, with an average frequency of once every five years. When it does that, it warms the world. An extreme El Niño wreaks havoc on weather patterns around the globe.

That splurge of warm water bleached coral on the Great Barrier Reef, through Indonesia, Japan and over to the Caribbean.

Then just five years later, during another El Niño, another bleaching event stretched its way around the globe.

By then, it was already clear what was causing all this. A paper in 1990 warned these events were being caused by climate change and bleaching “will probably continue and increase until coral-dominated reefs no longer exist”.

At that time the 1982 event was described as “the most widespread coral bleaching and mortality in recorded history” but today there is debate about whether it and the 1987 events’ severity was bad enough to count as a true “global bleaching event”.

That hardly matters now. In an age of climate change, records don’t last long.

In 1997-98, the world was hit by a second extreme El Niño – the strongest seen to date. Figures of how much coral died that year are hard to confirm but it is thought 16% of the world’s reefs were destroyed in a matter of months. About half of those might have been lost forever.

Mass bleachings – some global, some not – have continued ever since but until this year 1998 held on to the record for the worst yet. That was probably a result of an extended La Niña-like phase that suppressed temperatures until now. During that time, warm water was being buried in the Pacific Ocean, suppressing surface temperatures, and keeping bleachings in check.

The year 2016 looks set to blow 1998 out of the water. By some measures it’s the longest global bleaching event in history and, on the Great Barrier Reef, it’s definitely the worst.

The reef has been hit by at least three significant mass bleachings in recorded history. The first coincided with the global bleaching in 1998, then it got hit in 2002, and then again this year.

A Guardian analysis of the three events, based on data from aerial surveys, shows the increasing severity of each event, and how they smashed different parts of the reef.

The mechanism behind this incredible new trend is obvious and well understood. As Bloomberg Businessweek famously said on its cover after Hurricane Sandy, “It’s global warming, stupid.”

Since 1950 more than 90% of the excess heat our carbon emissions have trapped in the atmosphere has gone into the oceans. As a result their surface temperature has increased by 1C in just the past 35 years.

That puts the water much closer to the limit of what coral can bear. Then, when a surge of even warmer water comes through – often as a result of the irregular El Niño cycle – corals over large stretches get stressed, bleach and die.

So well understood is the mechanism that satellite data on water temperature is a good proxy for coral bleaching. Using that understanding, the US National Oceanographic and Atmospheric Administration looks at satellite data and produces “bleaching alerts” that represent a predicted stress response from coral.

In data produced exclusively for the Guardian by Mark Eakin, head of Coral Reef Watch at Noaa, we can now reveal exactly how stressful ocean temperatures have been increasing on the Great Barrier Reef over the 34 years that satellite data has been available.

Since 1982, just after mass bleachings were seen for the first time, the data shows that the average proportion of the Great Barrier Reef exposed to temperatures where bleaching or death is likely has increased from about 11% a year to about 27% a year.

Eakin says looking at that data revealed a clear trend that hadn’t been quantified before. “In seeing that what it immediately showed was that there was a real background pattern of increasing levels of thermal stress.

Combined with other stressors hitting the reef, this is having a devastating impact. Over that period, half the coral cover on the Great Barrier Reef has been lost – and that’s before the mass bleaching this year is taken into account.

That data has limitations – it’s not direct bleaching, but stress inferred from temperature readings. And it lumps extreme levels of stress – like what is being seen around Lizard Island now – with anything that is expected to cause mortality.

Despite that, it reveals the way global warming is leading to more regular bleaching and mortality.

“While there was a considerable amount of variability – from El Niños and other things – there was an obvious upward trend in the data,” Eakin says. “So you’re looking at the background warming, which is having a major effect on the corals.”

And just looking at the surface temperature of water around the Great Barrier Reef over the past 100 years leaves little doubt about the role of climate change.

Adding to this correlational data, researchers have examined exactly how much more likely the warm conditions on the Great Barrier Reef were as a result of carbon emissions.

They ran climate models thousands of times, and simulated a world with human CO2 emissions and a world without them. They found that in a world without humans and their carbon emissions, the conditions on the Great Barrier Reef that caused the current bleaching would have been virtually impossible. Today they’re still unusual, but have been made at least 175 times more likely as a result of our carbon emissions.

“In a world without humans, it’s not quite impossible that you’d get March sea surface temperatures as warm as this year, but it’s extremely unlikely,” Andrew King, a lead author of the study from the University of Melbourne, told the Guardian in April.

But what was even more concerning was how quickly things are predicted to get worse. “In the current climate it’s unusual but not exceptional. By the mid 2030s it will be average. And beyond that it will be cooler than normal if it was as warm as this year.”

That means the Great Barrier Reef is likely to be hit with conditions like this, on average, every second year in fewer than 20 years.

Many reef biologists approached by the Guardian have said this could mean it’s too late for the Great Barrier Reef. We may have already made its death inevitable. But since there’s still a chance it’s not too late, they all said it was imperative to keep fighting.

“Yes, maybe it’s too late,” Marshall told the Guardian. But he said that was no reason to not try to save it. “I’m not going to sit back and buy a Hummer and just let it all slide.”

And there have been signs that coral is more resilient than biologists used to think – it might be able to adapt and evolve and, while the weaker corals are probably doomed, maybe the stronger corals will be able to spread and take over. In some places, maybe reefs will even migrate further from the equator.

These tiny signs of hope are all biologists and conservationists can cling to. “With biology there are always things around the corner that we don’t know,” Marshall says. “These things are fantastically resilient and biologically programmed for survival.”

But hope requires action. And there are some powerful forces who don’t want to see light shone on on this particular murder.

And murder it is: we’ve known for decades that we’re to blame.

Cover-up

“It’s the great white lie,” Col McKenzie, the chief executive of the Association of Marine Park Tourism Operators, told a Queensland newspaper in April. “It’s not dead, white and dying. It’s under stress but it will bounce back.”

He tells the Guardian he’s furious at the media and at the scientists who have been making a big deal out of the bleaching event: “What I’m seeing is that my industry is being held out for ransom and is the whipping boy for the Greenies who want to be anti-coalmining. And, frankly, I think that’s bloody disgusting.”

He represents an industry that, as he puts, is “tied by the hip pocket to the health of the reef”.

In 2011-12 it was estimated tourism centred on the Great Barrier Reef generated $5.7bn for the economy and created 69,000 jobs.

McKenzie says the media coverage of the bleaching is a bigger risk to the industry than the bleaching itself. He says people are less likely visit the reef now that they think it’s in worse condition.

Jumping on this concern, the Australian government looks to be doing everything it can to downplay the bleaching. In May the Guardian revealed the Australian department of environment had intervened to have every mention of the Great Barrier Reef – and indeed every mention of the country – scrubbed from the final version of a UN report on climate change and world heritage sites. As a result, Australia was the only continent on the planet not mentioned.

When confronted with the revelation, the government told the Guardian it did it because: “Recent experience in Australia had shown that negative commentary about the status of world heritage properties impacted on tourism.”

The revelation came shortly after Australia’s environment minister, Greg Hunt, told a Queensland newspaper after seeing a David Attenborough documentary about the Great Barrier Reef: “The key point that I had from seeing the first of the three parts is that clearly, the world’s Great Barrier Reef is still the world’s Great Barrier Reef.”

The article ran with the headline: “Reports of reef’s death greatly exaggerated: Attenborough.”

In fact, Attenborough said that “the Great Barrier Reef is in grave danger”. And later: “The twin perils brought by climate change – an increase in the temperature of the ocean and in its acidity – threaten its very existence.”

Then in May and June, these concerns caused a split in the national coral bleaching taskforce, which was set up to monitor the bleaching event. It’s made up of 10 Australian institutions, some of them government agencies, and others university research centres and is led by Terry Hughes from James Cook University.

The group was about to release the results of its coral mortality surveys when two leading government agencies pulled out of the announcement.

Hughes and his university colleagues released the results anyway, on Monday 30 May, but with only part of the data. They announced that “35% of the corals are now dead or dying” in the “northern and central sections of the Great Barrier Reef”.

On Thursday of that week, Col McKenzie went on the attack, saying the results were “utter rubbish”.

“It seems that some marine scientists have decided to use the bleaching event to highlight their personal political beliefs and lobby for increased funding in an election year,” he said in a media release.

The results of surveys from the government agency the Great Barrier Reef Marine Park Authority told a different story, he said.

A day later the rest of the results were released by the government agencies. Attached to these was a long media release that aimed to dispel perceived exaggerations of the damage and highlight corals’ ability to recover.

Russell Reichelt, the marine park authority’s chairman and chief executive, told the Australian newspaper the agency had split from the group release because it wasn’t telling the whole story. He was quoted as saying that the maps illustrating the coral mortality exaggerated the impact, and that the exaggeration “suits the purpose” of the people sending it out.

The story ran on the front page of Australia’s only national newspaper declaring that “activist scientists” were distorting the data. “Marine park head denies coral bleaching crisis,” it screamed.

But the authority’s actual data, which revealed a striking 22% of coral on the Great Barrier Reef had been killed, was entirely consistent with the figures released earlier that week from the university partners – something Reichelt later acknowledged on social media.

It’s clear that a cabal of climate change deniers, worried tourism operators, and a conservative government have tried to whitewash the environmental disaster unfolding over the Great Barrier Reef.

McKenzie is no climate change denier and is quick to agree that climate change has caused the bleaching. But he has taken signs of coral’s adaptability to heart and is sure that the coral will adapt to higher temperatures under climate change. He thinks the reef will be fine.

He says the scientists who are making a lot of noise about the bleaching have overstepped a line. “The scientists decided to make some fairly strong statements about the health of the reef – and some fairly outrageous ones at that. I don’t think that’s what science is about. I believe scientists should be reporting the facts as they are, not sensationalising the issue.”

The fear that the media spotlight on the bleaching will stop people wanting to visit the reef runs deep in the tourism industry. So much so that tour operators have reportedly been routinely refusing to take conservationists, media and politicians to bleached parts of the reef.

But that alliance may be breaking down, with some tourism operators on the reef getting worried about its long-term health.

“Many tourism operators, they don’t want people not to come to the reef, so they’ve been reluctant to speak out,” says John Rumney, who has run diving and fishing tours on the Great Barrier Reef for the past four decades. “They are worried it will have a negative impact on the short-term cash flow.”

Rumney says that’s short-sighted since unless people speak up now there will be no reef in the future, and the industry won’t exist. He and other operators have broken away from the crowd and are speaking out. (McKenzie describes them as “the fringe dwellers of the industry”.)

In May the Guardian revealed that a group of more than 170 individuals and businesses in the tourism industry had written an open letter, published in a north Queensland newspaper, urging people to recognise the severity of the bleaching, and begging the government to take stronger action to save the reef.

“We are proud of our stewardship of this incredible resource,” they wrote. “We understand its value lies in looking after it. We hope the majority of the reef can recover but Australia must start doing everything it can to tackle the root cause of the coral bleaching, which is global warming.”

And, speaking to other tourism operators, it doesn’t appear these people are industry outsiders as McKenzie suggests.

Paul Crocombe is the manager of Adrenalin Dive, a business based in Townsville that takes tourists out to see the reef. He has been diving on the reef for more than 30 years and has been working in tourism for more than 20.

He’s concerned that the media reporting about the bleaching will impact tourist numbers but he acknowledges that it’s important to get the information out.

Crocombe says when tourists hear that 93% of the reef has been impacted by bleaching they expect to come and see that it’s all dead. Of course that’s not true.

In most of the places tourists go, only about 5% of the coral is likely to die, meaning they’ll hardly see any difference. In 2016 there is no reason for tourists to avoid most areas of the reef.

(Tourism operators were lucky – after Cyclone Winston devastated Fiji, it weakened and brought clouds and rain over the southern two-thirds of the reef, cooling the water there and protecting the majority of tourist destinations.)

“We were really fortunate this time with the coral bleaching that the majority of the mortality is a long way north of here,” Crocombe says. He’s very aware that if the sort of bleaching that hit Lizard Island and other areas was seen near Townsville or Port Douglas, tourism would have had a major, long-term problem.

“With the reporting on the threats to the reef, it has, again, a double-edged sword. I think it’s really important that people do understand that the reef is in danger and that if we don’t do something then, yes, we are going to have a significant impact on the reef.

“I think it’s really important that people do understand there are threats to the reef. Currently it is in reasonably good condition but I don’t think it will take a lot to tip it over the edge.”

So with more moderate tourism operators speaking out, efforts to hide the reef’s impending death might be failing. As that happens, and the world confronts reality, can the reef be saved?

The last chance

“You either do it properly or you give up on the reef, I think. It’s that bad,” says Jon Brodie from James Cook University. Since 1975 he has studied how to give coral reefs their best chance of surviving the various things thrown at them.

The solution to climate change itself is well-rehearsed. It’s not a scientific or technological problem but a political one. And a global one. We need to transition away from fossil fuels. That’s a sentiment that chimes with the Guardian’s “Keep it in the ground” campaign.

Climate change is the greatest threat facing the Great Barrier Reef and other coral reefs around the world.

According to the UN report on climate change that Australia had itself deleted from, and a paper in Nature it cites, a 2C rise in global surface temperatures will result in the loss of more than 95% of coral around the world.

If the world limits warming to 1.5C, we might save 10%. If we want to save 50% of what’s around right now, we need to limit warming to just 1.2C – and we’re already more than 80% of the way there.

The Australian government has committed to reductions in carbon emissions that aren’t even consistent with limiting warming to 2C. Worse still, the policies in place at the moment are widely acknowledged to be unable meet even those targets.

But to give the Great Barrier Reef a fighting chance of survival in current or future temperatures, it needs to be protected from an array of other assaults it is being hit with. Scientists refer to this as building reef resilience.

Nick Graham from James Cook University showed last year that almost 60% of reefs in the Seychelles recovered after they lost 90% of their coral following the 1998 global bleaching event. The reefs that recovered were those that were not being hit with pollution, weren’t being overfished, and when the reef managed to maintain a complex structure.

When it comes to the Great Barrier Reef, the biggest threat to resilience is water pollution.

It is being increasingly smothered with suspended sediment that blocks light; smeared with fertilisers that cause outbreaks of seaweed and coral-eating crown of thorns starfish; and poisoned with herbicides that kill the coral’s symbiotic algae.

Compared with what was happening before the 20th century, today there is almost three times as much sediment, about twice as much fertiliser and 17,000 extra kilograms of herbicide washing over the reef each year.

Brodie says this needs to be fixed immediately. And the bleaching this year is proof of that. “Climate change is coming on much quicker and stronger than we thought,” he says. “We used to think 2035 was soon enough to fix up water quality but we’ve had to revise that.”

Now, he says, if it’s not under control by 2025, it’s game over for the reef.

With an election campaign under way in Australia, which will deliver a government for at least three years, many are saying that this election is the last chance to squeeze commitments from politicians that could deliver the resilience the reef needs to survive.

So far the current Coalition government of Liberals and Nationals has committed $210m to improve water quality on the reef, and a further $6m to control crown of thorns starfish, if they win the election.

The Labor opposition has promised slightly more, with $500m to improve water quality.

The Greens, who could hold the balance of power in the next parliament, have so far focused their attention on climate change policies, with a seven-point plan aimed at transitioning Australia away from fossil fuels.

According to the best science, none of this is enough.

Brodie has written hundreds of papers and technical reports on the issue, and in May published a paper estimating what would be required to get the water to an adequate state by 2025. He said it would take $1bn a year between now and then.

As it stands, the major parties have committed to what amounts to tinkering around the edges, he says. A few hundred million here, a few million there.

“We know how to do it,” Brodie says. “In fact right now we’re spending a little bit of money doing some of it and we have made a little bit of progress with that little bit of money but we just need a lot more.”

He adds: “This is the last chance to do it, I think. If we don’t do it soon then we probably shouldn’t bother, really. It’s as bad as that now.”

Graphics by Nick Evershed and Ri Liu. Videos by Josh Wall. Opening footage courtesy of Exposure Labs, which is producing a feature film on the effects of climate change on oceans. Michael Slezak reported from Townsville, the Great Barrier Reef and Sydney