Coral bleaching has changed the Great Barrier Reef eternally
That splurge of warm water bleached coral on the Great Barrier Reef, through Indonesia, Japan and over to the Caribbean.
Then just 5 years later, during another El Nio, another bleaching event stretched its route around the globe.
By then, it was already clear what was causing all this.
A paper in 1990 alerted 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 historybut today there is debate about whether it and the 1987 events severity was bad enough to counting as a true global bleaching event.
That barely matters now. In an age of climate change, records dont last long.
In 1997 -9 8, the world was well received by a second extreme El Nio the strongest assured to date. Figures of how much coral succumbed that year are hard to confirm but it is thought
16% of the worlds 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 Nia-like phase that inhibited 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 its the longest global bleaching event in history and, on the Great Barrier Reef, its definitely the worst.
The reef has been hit by at the 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 seriousnes of each event, and how they smashed various regions of the reef.
Comparison maps of three major bleaching events in 1998, 2002 and 2016
The mechanism behind this incredible new tendency is obvious and so clear. As
Bloomberg Businessweek famously said on its encompas after Hurricane Sandy, Its global warming, stupid.
Since 1950 more than 90% of the excess heat our carbon emissions have trapped in the ambiance has gone into the oceans. As a outcome their surface temperature has increased by 1C in simply the past 35 years.
That sets 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 Nio 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 understand, the US National Oceanographic and Atmospheric Administration looks at spacecraft data and produces bleaching alertings that represent a predicted stress replies from coral.
In data produced exclusively for the Guardian by Mark Eakin, head of Coral Reef Watch at Noaa, we can now expose exactly how stressful ocean temperatures have been increasing on the Great Barrier Reef over the 34 years that satellite data has been available.
Coral stress index calculated from ocean temperatures from 1982 to 2016
Since 1982, just after mass bleachings were ensure 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 exposed a clear tendency that hadnt been quantified before. In seeing that what it immediately showed was that there was a real background pattern of increasing high levels of thermal stress.
Combined with other stressors hitting the reef, this is having a devastating impact. Over that period, half the coral cover-up on the Great Barrier Reef has been lost and thats before the mass bleaching this year is taken into account.
That data has restrictions its not direct bleaching, but stress inferred from temperature readings. And it lumps extreme high levels of stress like what is being insured around Lizard Island now with anything that is expected to cause mortality.
Despite that, it exposes the way global warming is leading to more regular bleaching and mortality.
While there was a considerable amount of variability from El Nios and other things there was an obvious upward tendency in the data, Eakin says. So youre looking at the background warming, which is having a major consequence 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.
Chart of coral sea surface temperatures from the Bureau of Meteorology, showing a general increase over period
Adding to this correlational data, researchers have analyse 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 days, 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 present bleaching would have been virtually impossible. Today theyre still unusual, but have been made at least 175 times more likely as a result of our carbon emissions.
In a world without humans, its not quite impossible that youd get March sea surface temperatures as warm as this year, but its extremely unlikely, Andrew King, a lead writer of such studies 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 its unusual but not exceptional. By the mid 2030 s 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 its too late for the Great Barrier Reef. We may have already constructed its demise inevitable. But since theres still a chance its not too late, they all said it was imperative to keep fighting.
Yes, perhaps its too late, Marshall
told the Guardian. But he said that was no reason to not try to save it. Im not going to sit back and buy a Hummer and is letting 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 likely doomed, perhaps the stronger corals will be able to spread and take over. In some places, perhaps 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 dont know, Marshall says. These the situation is fantastically resilient and biologically programmed for survival.
But hope requires action. And there are some powerful forces who dont want to see light glisten on on this particular assassination.
And murder it is: weve known for decades that were to blame.
Its the great white lie, Col McKenzie, the chief executive of the Association of Marine Park Tourism Operators,
told a Queensland newspaper in April. Its not dead, white and succumbing. Its under stress but it will bounce back.
He tells the Guardian hes furious at the means and at the scientists who have been making a big deal out of the bleaching event: What Im assuring 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 thats bloody disgusting.
He represents an industry that, as he puts, is tied by the hip pocket to the health of the reef.
In 2011 -1 2 it was estimated tourism centred on the Great Barrier Reef made $5.7 bn for the economy and made 69,000 jobs.
McKenzie says the media coverage of the bleaching is a bigger danger to the industry than the bleaching itself. He says people are less likely visit the reef now that they think its in worse condition.
Jumping on this concern, the Australian government seems to be doing everything it can to downplay the bleaching. In May the Guardian disclosed 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 outcome, Australia was the only continent on countries around the world 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.
Coral bleaching: We need to tell the truth without frightening reef tourists away
The revelation came soon after Australias environment minister, Greg Hunt, told a Queensland newspaper after find a David Attenborough documentary about the Great Barrier Reef: The key point that I had from considering the first of the three parts is that clearly, the worlds Great Barrier Reef is still the worlds Great Barrier Reef.
The article run with the headline: Reports of reefs demise greatly exaggerated: Attenborough.
In fact, Attenborough said that the Great Barrier Reef is in tomb hazard. 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 divide in the national coral bleaching taskforce, which is now being set up to monitor the bleaching event. Its 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 research 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 segments of the Great Barrier Reef.
On Thursday of that week, Col McKenzie went on the two attacks, saying the findings are utter rubbish.
It seems that some marine scientists have decided to use the bleaching event to highlight their personal political belief and lobby for increased fund 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 another story, he said.
A day afterwards the rest of the findings are released by the government agencies. Attached to these was a long media release that aimed to dispel perceived exaggerations of the damage and highlighting corals ability to recover.
Russell Reichelt, the marine park authority chairman and chief executive,
told the Australian newspaper the agency had split from different groups release because it wasnt telling the whole story. He was quoted as went on to say that the maps exemplifying the coral mortality exaggerated the impact, and that the exaggeration suits the purpose of the people sending it out.
The story run on the front page of Australias only national newspaper declaring that activist scientists were distorting the data. Marine park head denies coral bleaching crisis, it screamed.
But the authoritys actual data, which exposed a striking
22% of coral on the Great Barrier Reef had been killed, was solely consistent with the above figures released earlier that week from the university partners something Reichelt subsequently recognise on social media.
Its clear that a cabal of climate change deniers, fretted 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 “hes taken” signs of corals adaptability to heart and is sure that the coral will adapt to higher temperatures under climate change. He guesses 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 build some fairly strong statements about the health of the reef and some somewhat outrageous ones at that. I dont think thats 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 operates deep in the tourism industry. So much so that tour operators have
reportedly been routinely rejecting 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 dont want people not to come to the reef, so theyve been reluctant to speak out, says John Rumney, who has run diving and angling tours on the Great Barrier Reef for the past four decades. They are fretted it will have a negative impact on the short-term cash flow.
Rumney says thats short-sighted since unless people speak up now there will be no reef in the future, and the industry wonts exist. He and other operators have violated away from the crowd and are speaking out.( McKenzie describes them as the fringe dwellers of the industry .)
the Guardian revealed that a group of more than 170 individuals and industries in the tourism industry had written an open letter, published in a north Queensland newspaper, exhorting 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 retrieve 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 doesnt appear these people are industry outsiders as McKenzie suggests.
Paul Crocombe is the manager of Adrenalin Dive, a business are stationed 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.
Hes am worried that the media reporting about the bleaching will impact tourist numbers but he acknowledges that its 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 its all dead. Of course thats not true.
In most of the places tourists run, merely about 5% of the coral is likely to die, entailing theyll hardly assure significant differences. 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 rainfall 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. Hes very aware that if the sort of bleaching that reached Lizard Island and other areas was ensure 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 its really important that people do understand that the reef is in danger and that if we dont do something then, yes, we are going to have a significant impact on the reef.
I think its really important that people do understand there are threats to the reef. Currently it is in reasonably good condition but I dont think it will take a lot to tip it over the edge.
So with more moderate tourism operators speaking out, efforts to hide the reefs impending death might be failing. As that happens, and the world tackles reality, can the reef be saved?
The last chance
You either do it properly or you give up on the reef, I think. Its that bad, says Jon Brodie from James Cook University. Since 1975 he has examined how to give coral reefs their best opportunity of surviving the various things hurled at them.
The solution to climate change itself is well-rehearsed. Its not a scientific or technological problem but a political one. And a global one. We need to transition away from fossil fuels. Thats a sentiment that chimes with
the Guardians Maintain it in the ground campaign.
Climate change is the greatest threat facing the Great Barrier Reef and other coral reef 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 1.5 C, we might save 10%. If we want to save 50% of whats around right now, we need to limit warming to simply 1.2 C and were already more than 80% of the way there.
The Australian government has committed to reductions in carbon emissions that arent even consistent with limiting warming to 2C. Worse still, the policies in place at the moment are widely acknowledged to be unable gratify 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 in accordance with the 1998 global bleaching event. The reef that recovered were those that were not being hit with pollution, werent 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.
A inundate plume from Maria creek, near Mission Beach, heading towards the Great Barrier Reef. Sediment, fertilisers and herbicides attack the reefs resilience. Photo: AFP/ Getty Images
It is being increasingly suffocated with suspended sediment that blocks illuminate; smeared with fertilisers that cause outbreaks of seaweed and coral-eating crown of thorns starfish; and poisoned with herbicides that kill the corals symbiotic algae.
Compared with what was happening before the 20 th 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 believed, he says. We used to think 2035 was soon enough to fix up water quality but weve had to revise that.
Now, he says, if its not under control by 2025, its game over for the reef.