In early 2016, we heard that the reef had suffered the worst bleaching ever recorded. Surveys published in June that year estimated that 93% of coral on the vast northern section of the reef was bleached, and 22% had already been killed.
Coral reefs are complex ecosystems that are affected by many factors. Changes in sea surface temperatures, rainfall, cloudiness, agricultural runoff, or water quality can affect a reef’s health and resilience to stress.
Early analysis of the 2016 bleaching suggested that the Great Barrier Reef was suffering from thermal stress brought on by human-caused climate change.
Our study took a new and comprehensive approach to examine these multiple climatic and environmental influences.
We set out to answer the crucial question: could anything else have bleached the Great Barrier Reef, besides human-induced climate change?
The results were clear. Using a suite of climate models, we found that the significant warming of the Coral Sea region was likely caused by greenhouse gases from human activities. This warming was the primary cause of the extreme 2016 bleaching episode.
Our study showed that although the 2016 El Niño probably also contributed to the bleaching, this was a secondary contributor to the corals’ thermal stress. The major factor was the increase in temperatures because of climate change.
We next analysed other environmental data. Previous research has found that corals at sites with better water quality (that is, lower concentrations of pollution particles) are more resilient and less prone to bleaching.
Pollution data used in our study show that water quality in 2016 may have been better than in previous bleaching years. This means that the Great Barrier Reef should have been at lower risk of bleaching compared to long-term average conditions, all else being equal. Instead, record bleaching hit the reef as a result of the warming temperature trend.
The final part of our investigation involved comparing the conditions behind the record 2016 bleaching with those seen in previous mass bleaching episodes on the Great Barrier Reef, in 1997-98 and 2010-11.
When we analysed these previous events on the Reef, we found very different factors at play.
In 1997-98 the bleaching coincided with a very strong El Niño event. Although an El Niño event also occurred in 2016, the two were very different in terms of the distribution of unusually warm waters, particularly in the eastern equatorial Pacific. In 1997-98, the primary cause of the bleaching – which was less severe than in 2016 – was El Niño.
In 2010-11, the health of the Great Barrier Reef was impaired by runoff. That summer brought record high rainfall to eastern Australia, causing widespread flooding across Queensland. As a result of the discharge of freshwater onto the reef reducing the salinity, bleaching occurred.
There have been many reports in recent years warning of trouble for the Great Barrier Reef. Sadly, our study is yet another warning about the reef’s future – perhaps the most comprehensive warning yet. It tells us that the 2016 bleaching differed from previous mass bleaching events because it was driven primarily by human-induced climate warming.
This puts the Great Barrier Reef in grave danger of future bleaching from further greenhouse warming. The local environmental factors that have previously helped to protect our reefs, such as good water quality, will become less and less able to safeguard corals as the oceans warm.
Now we need to take immediate action to reduce greenhouse gas emissions and limit further warming. Without these steps, there is simply no future for our Great Barrier Reef.
Melting of Antarctica’s ice can trigger rapid warming on the other side of the planet, according to our new research which details how just such an abrupt climate event happened 30,000 years ago, in which the North Atlantic region warmed dramatically.
This idea of “tipping points” in Earth’s system has had something of a bad rap ever since the 2004 blockbuster The Day After Tomorrow purportedly showed how melting polar ice can trigger all manner of global changes.
But while the movie certainly exaggerated the speed and severity of abrupt climate change, we do know that many natural systems are vulnerable to being pushed into different modes of operation. The melting of Greenland’s ice sheet, the retreat of Arctic summer sea ice, and the collapse of the global ocean circulation are all examples of potential vulnerability in a future, warmer world.
Of course it is notoriously hard to predict when and where elements of Earth’s system will abruptly tip into a different state. A key limitation is that historical climate records are often too short to test the skill of our computer models used to predict future environmental change, hampering our ability to plan for potential abrupt changes.
One of the most important sources of information on past climate tipping points are the kilometre-long cores of ice drilled from the Greenland and Antarctic ice sheets, which preserve exquisitely detailed information stretching back up to 800,000 years.
The Greenland ice cores record massive, millennial-scale swings in temperature that have occurred across the North Atlantic region over the past 90,000 years. The scale of these swings is staggering: in some cases temperatures rose by 16℃ in just a few decades or even years.
Twenty-five of these major so-called Dansgaard–Oeschger (D-O) warming events have been identified. These abrupt swings in temperature happened too quickly to have been caused by Earth’s slowly changing orbit around the Sun. Fascinatingly, when ice cores from Antarctica are compared with those from Greenland, we see a “seesaw” relationship: when it warms in the north, the south cools, and vice versa.
Attempts to explain the cause of this bipolar seesaw have traditionally focused on the North Atlantic region, and include melting ice sheets, changes in ocean circulation or wind patterns.
But as our new research shows, these might not be the only cause of D-O events.
We know that there have been major collapses of the Antarctic ice sheet in the past, raising the possibility that these may have tipped one or more parts of the Earth system into a different state. To investigate this idea, we analysed an ancient New Zealand kauri tree that was extracted from a peat swamp near Dargaville, Northland, and which lived between 29,000 and 31,000 years ago.
Through accurate dating, we know that this tree lived through a short D-O event, during which (as explained above) temperatures in the Northern Hemisphere would have risen. Importantly, the unique pattern of atmospheric radioactive carbon (or carbon-14) found in the tree rings allowed us to identify similar changes preserved in climate records from ocean and ice cores (the latter using beryllium-10, an isotope formed by similar processes to carbon-14). This tree thus allows us to compare directly what the climate was doing during a D-O event beyond the polar regions, providing a global picture.
The extraordinary thing we discovered is that the warm D-O event coincided with a 400-year period of surface cooling in the south and a major retreat of Antarctic ice.
When we searched through other climate records for more information about what was happening at the time, we found no evidence of a change in ocean circulation. Instead we found a collapse in the rain-bearing Pacific trade winds over tropical northeast Australia that was coincident with the 400-year southern cooling.
To explore how melting Antarctic ice might cause such dramatic change in the global climate, we used a climate model to simulate the release of large volumes of freshwater into the Southern Ocean. The model simulations all showed the same response, in agreement with our climate reconstructions: regardless of the amount of freshwater released into the Southern Ocean, the surface waters of the tropical Pacific nevertheless warmed, causing changes to wind patterns that in turn triggered the North Atlantic to warm too.
Future work is now focusing on what caused the Antarctic ice sheets to retreat so dramatically. Regardless of how it happened, it looks like melting ice in the south can drive abrupt global change, something of which we should be aware in a future warmer world.
There was a brief period of consensus ushered in by John Howard’s belated realisation in 2006 that a price had to be put on carbon dioxide emissions. But by December 2009 the Nationals, and enough Liberals, had decided that this was a mistake, and have opposed explicit carbon pricing ever since.
But the Liberal Party’s tussles over climate and energy policy (as distinct from denying the science itself) go back even further – some 30 years.
Early days and ‘early’ action
It’s hard to believe it now, but the Liberal Party took a stronger emissions target than Labor to the 1990 Federal election. Yet green-minded voters were not persuaded, and Labor squeaked home with their support. After that episode the Liberals largely gave on courting green voters, and under new leader John Hewson the party tacked right. Ironically, considering Hewson’s climate advocacy today, back then his Fightback! policy was as silent on climate change as it was on the price of birthday cakes.
In his excellent 2007 book High and Dry, former Liberal speech writer Guy Pearse recounts how in the mid-1990s he contacted the Australian Conservation Foundation, offering to to canvass Coalition MPs to “find the most promising areas of common ground” on which to work when the party returned to government. The ACF was “enthusiastic, if a little bemused at the novelty of a Liberal wanting to work with them”. Most Liberal MPs – including future environment minister Robert Hill and future prime minister Tony Abbott – were “strongly supportive” of the idea. But others (Pearse names Eric Abetz and Peter McGauran) were “paranoid that some kind of trap was being laid”. Nothing came of it.
Elected in 1996, Howard continued the staunch hostility to the United Nations climate negotiations that his Labor predecessor Paul Keating had begun. Not all businessmen were happy. Leading up to the crucial Kyoto summit in 1997, the Sydney Morning Herald reported how a “delegation of scientists and financiers” led by Howard’s local party branch manager Robert Vincin and Liberal Party grandee Sir John Carrick lobbied the prime minister to take a more progressive approach. Howard did not bend.
Howard stayed unmoved until 2006 when, facing a perfect storm of rising public climate awareness and spiralling poll numbers, he finally relented. Earlier that year a group of businesses convened by the Australian Conservation Foundation produced a report titled The Early Case for Business Action. “Early” is debatable, given that climate change had already been a political issue since 1988, but more saliently the report tentatively suggested introducing a carbon price. And Howard finally relented.
The carbon wars
The ensuing ten years after Kevin Rudd’s defeat of Howard don’t need much recapping here (go here for all the details). But one interesting phenomenon that has emerged from the policy wreckage is the emergence of some very unusual coalitions to beg for certainty.
Then, after the seminal South Australia blackout last September, a surprisingly diverse group of industry and consumer bodies – the Australian Energy Council, Australian Industry Group, Business Council of Australia, Clean Energy Council, Energy Users Association, Energy Consumers Australia, Energy Networks Association and Energy Efficiency Council – called on federal and state energy ministers to “work together to craft a cooperative and strategic response to the transformation underway in Australia’s energy system”.
It’s in this light that the new Conservatives for Conservation lobbying effort should be seen. Its spearhead Kristina Photios surely knows she has no chance of converting the committed denialists, but she can chip away at the waverers currently giving them comfort and power.
Questions on notice
Of course, there are always cultural (or even psychological) issues, but you’d think that conservation would be a no-brainer for conservatives (the clue should be in the name).
There are a few questions, of course (with my answers in brackets).
Where were all the people who are now calling for policy certainty back in 2011 when Tony Abbott was declaring his oath to kill off the carbon tax? (They were AWOL.)
Will any business show any interest in building a new coal-fired power station? (No.)
Is renewable energy technology now advanced enough for them to make serious money? (We shall see.)
Can we make up for lost time in our emissions reductions? (No, and we have already ensured more climate misery than there would have been with genuinely early climate action.)
Will the Liberals further water down the Clean Energy Target proposal? (Probably.)
What will Tony Abbott say to UK climate sceptic think tank the Global Warming Policy Foundation when he gives a speech on October 6? (Who knows –
grab your popcorn!).
What will happen to the Liberals in the medium term? (Who knows, but Michelle Grattan of this parish has some intriguing ideas.)
Are there reasons to be cheerful? (Renewable energy journalist Ketan Joshi thinks so.)
Perhaps the last word on this issue should go to John Hewson, who noted last year:
The “right” love to speak of the debt and deficit problem as a form of “intergenerational theft”, yet they fail to see the climate challenge in the same terms, even though the consequences of failing to address it substantively, and as a matter of urgency, would dwarf that of the debt problem. The “right” is simply “wrong”. It’s political opportunism of the worst sort, and their children and grandchildren will pay the price.
I’ve wanted to be a scientist since I was five years old.
My idea of a scientist was someone in a lab, making hypotheses and testing theories. We often think of science only as a linear, objective process. This is also the way that science is presented in peer reviewed journal articles – a study begins with a research question or hypothesis, followed by methods, results and conclusions.
It turns out that my work now as a climate scientist doesn’t quite gel with the way we typically talk about science and how science works.
Climate change, and doing climate change research, has changed the way I see and do science. Here are five points that explain why.
Falsifiability is the idea that an assertion can be shown to be false by an experiment or an observation, and is critical to distinctions between “true science” and “pseudoscience”.
Climate models are important and complex tools for understanding the climate system. Are climate models falsifiable? Are they science? A test of falsifiability requires a model test or climate observation that shows global warming caused by increased human-produced greenhouse gases is untrue. It is difficult to propose a test of climate models in advance that is falsifiable.
This difficulty doesn’t mean that climate models or climate science are invalid or untrustworthy. Climate models are carefully developed and evaluated based on their ability to accurately reproduce observed climate trends and processes. This is why climatologists have confidence in them as scientific tools, not because of ideas around falsifiability.
2. There’s lots of ways to interpret data
Climate research is messy. I spent four years of my PhD reconstructing past changes in Australian and Indonesian rainfall over many thousands of years. Reconstructing the past is inherently problematic. It is riddled with uncertainty and subject to our individual interpretations.
During my PhD, I submitted a paper for publication detailing an interpretation of changes in Indonesian climates, derived from a stalagmite that formed deep in a cave.
My coauthors had disparate views about what, in particular, this stalagmite was telling us. Then, when my paper was returned from the process of peer review, seemingly in shreds, it turns out the two reviewers themselves had directly opposing views about the record.
What happens when everyone who looks at data has a different idea about what it means? (The published paper reflects a range of different viewpoints).
Another example of ambiguity emerged around the discussion of the hiatus in global warming. This was the temporary slowdown in the rate of global warming at the Earth’s surface occurring roughly over the 15 year period since 1997. Some sceptics were adamant that this was unequivocal proof that the world was not warming at all and that global warming was unfounded.
There was an avalanche of academic interest in the warming slowdown. It was attributed to a multitude of causes, including deep ocean processes, aerosols, measurement error and the end of ozone depletion.
Ambiguity and uncertainty are key parts of the natural world, and scientific exploration of it.
3. Sometimes the scientist matters as well as the results
I regularly present my scientific results at public lectures or community events. I used to show a photo depicting a Tasmanian family sheltering under a pier from a fire front. The sky is suffused with heat. In the ocean, a grandmother holds two children while their sister helps her brother cling to underside of the pier.
After a few talks, I had to remove the photo from my PowerPoint presentation because each time I turned around to discuss it, it would make me teary. I felt so strongly that the year we were living was a chilling taste of our world to come.
Just outside of Sydney, tinderbox conditions occurred in early spring of 2013, following a dry, warm winter. Bushfires raged far too early in the season. I was frightened of a world 1°C hotter than now (regardless of what the equilibrium climate sensitivity turns out to be).
At public lectures and community events, people want to know that I am frightened about bushfires. They want to know that I am concerned about the vulnerability of our elderly to increasing summer heat stress. People want to know that, among everything else, I remain optimistic about our collective resilience and desire to care for each other.
Communicating how we connect with scientific results is also important part of the role of climate scientists. That photo of the family who survived the Tasmanian bushfire is now back in my presentations.
4. Society matters too
In November 2009, computer servers at the University of East Anglia were illegally hacked and email correspondence was stolen.
A selection of these emails was published publicly, focusing on quotes that purported to reveal dishonest practices that promoted the myth of global warming. The “climategate” scientists were exhaustively cleared of wrongdoing.
On the surface, the climategate emails were an unpleasant but unremarkable event. But delving a little deeper, this can be seen as a significant turning point in society’s expectations of science.
While numerous fastidious reviews of the scientists cleared them of wrongdoing, the strong and ongoing public interest in this matter demonstrates that society wants to know how science works, and who “does” science.
There is a great desire for public connection with the processes of science and the outcomes of scientific pursuits. The public is not necessarily satisfied by scientists working in universities and publishing their finding in articles obscured by pay walls, which cannot be publicly accessed.
A greater transparency of science is required. This is already taking off, with scientists communicating broadly through social and mainstream media and publishing in open access journals.
Enlisting non-expert volunteers allows researchers to investigate otherwise very difficult problems, for example when the research would have been financially and logistically impossible without citizen participation.
The OzDocs project involved volunteers digitising early records of Australian weather from weather journals, government gazettes, newspapers and our earliest observatories. This project provided a better understanding of the climate history of southeastern Australia.
Personal computers also provide another great tool for citizen collaborators. In one ongoing project, climate scientists conduct experiments using publicly volunteered distributed computing. Participants agree to run experiments on their home or work computers and the results are fed back to the main server for analysis.
While we often think of scientists as trained experts working in labs and publishing in scholarly journals, the lines aren’t always so clear. Everyone has an opportunity to contribute to science.
My new book explores this space between the way science is discussed and the way it takes place.
This isn’t a criticism of science, which provides a useful way to explore and understand the natural world. It is a celebration of the richness, diversity and creativity of science that drives this exploration.
But that doesn’t mean the Reef is out of danger. Afforded World Heritage recognition in 1981, the Reef has been on the warning list for nearly three years. It’s not entirely evident why UNESCO decided not to list the Reef as “in danger” at this year’s meeting, given the many ongoing threats to its health.
However, the World Heritage Committee has made it clear they remain concerned about the future of this remarkable world heritage site.
The reef is still in deep trouble
UNESCO’s draft decision (the adopted version is not yet released) cites significant and ongoing threats to the Reef, and emphasises that much more work is needed to get the health of the Reef back on track. Australia must provide a progress report on the Reef in two years’ time – and they want to see our efforts to protect the reef accelerate.
About 40% of this vegetation clearing is in catchments that drain to the Great Barrier Reef. Land clearing contributes to gully and streambank erosion. This erosion means that soil (and whatever chemical residues are in it) washes into waterways and flows into reef lagoon, reducing water quality and affecting the health of corals and seagrass.
Landclearing also directly contributes to climate change, which is the single biggest threat to the Reef. The recent surge in land clearing in Queensland alone poses a threat to Australia’s ability to meet its 2030 emissions reduction target. Yet attempts by the Queensland Government to control excessive land clearing have failed – a concern highlighted by UNESCO in the draft decision.
A time for action, not celebration
The Reef remains on UNESCO’s watch list. Just last month the World Heritage Committee released a report concluding that progress towards achieving water quality targets had been slow, and that it does not expect the immediate water quality targets to be met.
The draft decision still expressed UNESCO’s “serious concern” and “strongly encouraged” Australia to “accelerate efforts to ensure meeting the intermediate and long-term targets of the plan, which are essential to the overall resilience of the property, in particular regarding water quality”.
This means reducing run-off of sediment, nutrients and pollutants from our towns and farmlands. Improving water quality can help recovery of corals, even if it doesn’t prevent mortality during extreme heatwaves.
The Great Barrier Reef is the most biodiverse of all the World Heritage sites, and of “enormous scientific and intrinsic importance” according to the United Nations. A recent report by Deloitte put its value at A$56bn. It contributes an estimated A$6.4bn annually to Australia’s economy and supports 64,000 jobs.
But the reef cannot exist in the long term without international efforts to curb global warming. To address climate change and reduce emissions, we need to act both nationally and globally. Local action on water quality (the focus of the Reef 2050 Plan) does not prevent bleaching, or “buy time” to delay action on emissions.
We need adequate funding for achieving the Reef 2050 Plan targets for improved water quality, and a plan to reach zero net carbon emissions. Without that action, an “in danger” listing seems inevitable in 2020. But regardless of lists and labels, the evidence is clear. The Great Barrier Reef is dying before our eyes. Unless we do more, and fast, we risk losing it forever.
Last week, Sydney radio announcer Alan Jones lambasted those concerned about climate change and what he called “renewable energy rubbish”.
Jones has been loose with the facts in the past, having been Factchecked in 2015 after confusing kilowatts with megawatts and quoting a cost for wind power he later confessed “where the 1502 [dollars per megawatt hour that he stated] comes from, I have absolutely no idea”.
Jones, who chaired the much hyped but poorly attended 2013 national rally against wind farms in June 2014 (see photo) told his listeners last week wind farms are “buggering up people’s health”.
Their report predictably savaged wind farms, while Labor Senator Anne Urquhart’s minority report was the only one I found to be evidence-based.
Jones then went on to interview Dr Mariana Alves-Periera, from the private Lusophona University in Portugal (world university ranking 1,805, and impact ranking 2,848) whom he described as a distinguished international figure.
She was “recognized internationally” and had published “over 50” scientific papers over 30 years, something of a modest output. Jones, who may or may not have read any of these publications, told listeners her findings were “indisputable”, there was “no opposing scientific evidence” and again in emphasis, “none of [her papers] have been disputed” to which Alves-Periera agreed instantly “no they haven’t”.
This is an interesting interpretation of the scientific reception that has greeted the work of the Lisbon group on the unrecognized diagnosis of “vibroacoustic disease” (or VAD), a term they have made their own.
I first encountered Alves-Periera when she spoke via videoconference to a NHMRC meeting on wind farms and health in 2011. She spoke to a powerpoint presentation which highlighted the case of a schoolboy who lived near wind turbines. Her claim was the boy’s problems at school were due to his exposure to the turbines, as were cases of “boxy foot” in several horses kept on the same property.
Intrigued by this n=1 case report, I set out with a colleague to explore the scientific reception that “vibroacoustic disease” had met. We published our findings in the Australian and New Zealand Journal of Public Health 2013.
We found only 35 research papers on VAD. None reported any association between VAD and wind turbines. Of the 35 papers, 34 had a first author from the Lusophona University-based research group. Remarkably, 74% of citations to these papers were self-citations by members of the group.
In other words, just shy of three quarters of all references to VAD were from the group who were promoting the “disease”. In science, median self-citation rates are around 7%. We found two unpublished case reports from the group presented at conferences which asserted that VAD was “irrefutably demonstrated” to be caused by wind turbines. We listed eight reasons why the scientific quality of these claims were abject.
In 2014 Alves-Periera and a colleague defended their work in a letter to the journal and I replied. They described themselves as the “lead researchers in vibroacoustic disease”. But as we had shown, they are almost the only researchers who were ever active on this topic, with self-citation rates seldom seen in research.
Other experts have taken a different view of the group’s work. One of the world’s leading acousticians Geoff Leventhall who also spoke at the NHMRC’s 2011 meeting, wrote in a 2009 submission to the Public Service Commission of Wisconsin about the Lisbon group’s VAD work.
The evidence which has been offered [by them] is so weak that a prudent researcher would not have made it public.
disease itself has not gained clinical recognition.
Leventhall concluded his review by saying:
One is left with a very uncomfortable feeling that the work of the VAD group, as related to the effects of low levels of infrasound and low frequency noise exposure, is on an extremely shaky basis and not yet ready for dissemination. The work has been severely criticised when it has been presented at conferences. It is not backed by peer reviewed publications and is available only as conference papers which have not been independently evaluated prior to presentation.
Jones told his listeners the reason wind turbines are not installed on Bondi Beach, down Sydney’s Macquarie Street or Melbourne’s Collins Street was because governments “know they are harmful to health”. His beguiling logic here might perhaps also be the same reason we don’t see these iconic locations given over to mining or daily rock concerts. Most people would understand there are other factors that explain the absence of both wind turbines, mines or daily rock concerts in such locations.
Jones has given air time to a Victorian woman who is a serial complainant about her local wind farm and who has written:
Around the Macarthur wind farm, residents suffer from infrasound emitted by the turbines, even when they’re not operating.
At a time when we are seeing unparalleled increases in renewable energy and reductions in fossil fuels all over the world, one wonders why this is still public discussion in Australia.
It may be startling to hear this in one concentrated burst, from a senator, last thing on a Tuesday afternoon, but if you’re familiar with the more conspiratorial corners of the internet this was all fairly pedestrian stuff.
What was more surprising, at least in passing, was Roberts comparing himself to Socrates:
Like Socrates, I love asking questions to get to the truth.
A Socratic questioner in the Senate! The gadfly of Athens, who cheerfully punctured the delusions of the comfortable and reduced them to frozen bewilderment with just a few cheerfully framed questions like some Attic Columbo, has apparently taken up residence in the red chamber. This should be a golden age for rational inquiry, right?
The choice of Socrates, like that of Galileo, is no accident. Both fit neatly into a heroic “one brave man against the Establishment” narrative of scientific progress that climate denialists like to identify with. Both eventually changed the trajectory of human knowledge. But along the way, both suffered persecution. Galileo was made to recant his “heretical” heliocentrism under threat of torture and spent his last years under house arrest. Socrates, charged with impiety and corrupting the youth and denounced in court by one Meletus, was put to death. Of course that’s not nearly as rough as the brutal suppression of Malcolm Roberts, who has been cruelly oppressed with a three year Senate seat and a guest slot on Q&A. But you get the idea.
Most importantly, both Socrates and Galileo function here as emblems of a kind of epistemic individualism. They’re ciphers for a view of knowledge generation as a contest between self-sufficient individual thinkers and a faceless, mediocre ‘they,’ instead of a collective and social process governed by internal disciplinary norms and standards.
Roberts doesn’t simply like asking questions – anyone can do that. No, he wants to be like Socrates: someone who refuses to accept the answers he’s given, and dismantles them with clinical, exhaustive precision. Malcolm Roberts wants to work it all out for himself, scientific community be damned. If Socrates could, why can’t he? Why can’t each of us?
But Socrates, living at the dawn of scholarly inquiry, had the luxury of being a polymath. “Philosopher” simply means “lover of wisdom,” and early philosophers were forced to be rather promiscuous with that love. Physicist, logician, meteorologist, astronomer, chemist, ethicist, political scientist, drama critic: the Greek philosopher was all of these and more by default. The intellectual division of labour had not yet taken place, because all fields of inquiry were in their infancy.
Fast forward two and a half thousand years and the situation is radically different. The sciences have long since specialised past the point where non-specialists can credibly critique scientific claims. There is now simply too much knowledge, at too great a pitch of complexity, for anyone to encompass and evaluate it all. The price we pay for our expanding depth of knowledge is that what we know is increasingly distrubuted between the increasingly specialised nodes of increasingly complex informational networks.
That fact, in turn, emphasises our mutual epistemic dependence. I rely daily on the expert competence and good will of thousands of people I never see and will never meet, from doctors to builders to engineers and lawyers – and climate scientists, who wrangle with the unimaginably complex fluid dynamics of our planet.
So what do you if you find yourself up against a network of specialist knowledge that disagrees with your core beliefs? Do you simply accept that you’re not in a position to assess their claims and rely, as we all must, on others? Do you, acknowledging your limitations, defer to the experts?
If you’re Socrates today, then yes, you probably do. The true genius of Socrates as Plato presents him that he understands his limitations better than anyone around him:
And is not this the most reprehensible form of ignorance, that of thinking one knows what one does not know? Perhaps, gentlemen, in this matter also I differ from other men in this way, and if I were to say that I am wiser in anything, it would be in this, that not knowing very much about the other world, I do not think I know. (Apology 29b)
But deferring to those who know better is not the sort of Socrates Malcolm Roberts wants to be. If you want to be a Roberts-style Socrates, instead of conceding your ignorance, you cling to some foundational bit of putative knowledge that allows you to dismiss anything else that’s said, like so:
It is basic. The sun warms the earth’s surface. The surface, by contact, warms the moving, circulating atmosphere. That means the atmosphere cools the surface. How then can the atmosphere warm it? It cannot. That is why their computer models are wrong.
This is a familiar move to anyone who’s ever watched a 9/11 truther at work. While “jet fuel can’t melt steel beams!” has become a punchline, in some ways it’s the perfect battle-cry for epistemic rebellion. It asserts that if you just cling to some basic fact or model, you can use it to reject more complicated scenarios or models that seem to contradict that fact.
That move levels the playing field and hands power back to the disputant. Your advanced study of engineering or climatology, be it ever so impressive, can’t override my high school physics or chemistry. My understanding of how physical reality works is simple, graspable, and therefore true; yours is complex, counterintuitive, esoteric, and thus utterly suspect. I’m Plato’s Socrates: earthy, self-sufficient and impervious to sophistry; you, by contrast, are Aristophanes’ Socrates, vain and unworldly, suspended in your balloon far above the healthy common sense of the demos, investing the clouds with your obsessions.
This leaves our would-be Socrates with the awkward fact that all those experts still disagree with him. How do you respond in the face of such disconfirmatory data? You could abandon your hypothesis, or you could deploy what Imre Lakatos called an ‘auxiliary hypothesis’ to defend it.
In Roberts’ case, as with many conspiracy theorists, this auxiliary hypothesis takes the form of a scattergun accusation. Climate science isn’t just mistaken, or even just inept, but “fraudulent.” Roberts is quite prepared to accuse thousands of people whose lives he knows nothing about of conscious and systemic corruption rather than admit he might be wrong.
From within Roberts’ rather Manichean worldview, that might seem to make a certain kind of sense: the forces of freedom are fighting an apocalyptic battle against the forces of repression. The enemy is positively evil, with its cooked climate data and insidious agendas and overtaxed bread. There is no need to spare the feelings of a foe so wicked. Those greedy bastards knew exactly what they were doing when they signed up for Socialist Climate Data Manipulation Studies in O-Week.
For anyone who claims to care about the quest for knowledge like Socrates did, the moral recklessness of such an accusation, from someone in such a position of power, should be cause for alarm. And when you’re trying to destroy the reputation of researchers because their message doesn’t suit your free-market pieties, you might just be more Meletus than Socrates.
Over three weeks, Australians have been taken on an incredible journey through the biology, beauty and wonder of the Great Barrier Reef, guided by Sir David Attenborough.
As individuals who have had the privilege of working on the Reef for much of our lives, the wonderful storytelling, exquisite photography and stunning production of the Great Barrier Reef with David Attenborough has been inspiring. It’s a great reminder of how lucky we are to have this wonder of nature right on our doorstep.
Particularly special has been the wonderful black-and-white footage of Sir David’s first visit to the Reef in 1957, a trip down memory lane. His attachment and fascination with the Reef are hard to dismiss.
However, as the curtain closes on this wonderful series, Sir David concludes that the Reef that he visited nearly 60 years ago is very different from today.
The Great Barrier Reef is in grave danger. The twin perils brought by climate change – an increase in the temperature of the ocean and in its acidity – threaten its very existence. – Sir David Attenborough
We should not be too surprised. Reef scientists have been warning about this for decades. In 1998, the warmest year on record at the time, the world lost around 16% of its coral reefs in the first global-scale mass coral bleaching event.
Before the current bleaching, the reef bleached severely in 1998 and 2002, with a substantial bleaching event in 2006 around the Keppel Islands. Outside these events, there has been moderate mass bleaching on the reef since the early 1980s (particularly 1983 and 1987), although never to the extent and intensity that we are witnessing today.
Rising sea temperatures
The current bleaching event has drawn widespread media coverage. One of the arguments we have seen raised is that coral bleaching is natural – and that the reef will bounce back as it always has, or even adapt to warming seas.
It is true that certain coral species, and even certain individual colonies within the same species, do perform better than others when stressed by warmer-than-normal sea temperatures. However, the extent of these differences is only 1-2℃. Given that even moderate climate change projections involve temperatures 2-3℃ higher than today, these differences offer little comfort for reefs like the Great Barrier Reef in a warmer world.
The observation that corals grow in warm areas of the globe is a demonstration that corals can and do adapt to local temperatures. However, the time frames involved are hundreds of years, not a single decade. Current rates of warming are much faster than anything for tens of millions of years, which makes the prospect of evolution keeping pace with a changing ocean even more improbable.
Mass bleaching is a new phenomenon that was first reported in the early 1980s. Before this, there are no reports of corals bleaching en masse across any coral reef or ocean region.
Experts are in agreement that mass coral bleaching and death on the Great Barrier Reef is driven by climate change resulting from human activities (mainly burning fossil fuels). This is the conclusion at the heart of the latest consensus of the United Nations scientific report.
Rising sea temperatures coupled with strong El Niños are unfortunately pushing corals to their thermal tolerance limits and beyond. It only takes a temperature increase of 1-2℃ to disrupt the special relationship between corals and tiny marine algae that live inside their tissue, resulting in bleached corals.
In fact, as CO₂ concentrations rise, sea temperatures will continue to climb – increasing the likelihood that mass coral bleaching events will become more frequent and more destructive. Recent research has shown that near-future increases in local temperature of as little as 0.5℃ may lead to significant degradation of the Great Barrier Reef.
Rising temperatures are not the only climate threat. Cyclones are predicted to become stronger (if less frequent) in a warmer world. Since 2005 there have been eight cyclones on the reef of category 3 or above – more than previous decades. We would argue this is evidence that these predictions are already coming true and form part of our current reality.
Heat stress is not just affecting corals on the Great Barrier Reef either. We are seeing reports of bleaching across all of Australia’s coral real estate (Coral Sea, Torres Strait, Kimberley, North West Shelf), the South Pacific and the central and western Indian Ocean.
It is likely only a matter of time before we start to see reports of bleaching from other coral reefs around the world. We are indeed dealing with changing times and a global issue.
It’s not too late to act
It’s not too late to act – but we will need very deep and significant action to occur within three to five years or face a collapse of ecosystems like the Great Barrier Reef.
However, it does require strong, immediate and decisive action from our political leaders.
In the lead-up to the federal election, we believe that four major steps are required by our leaders to ensure a future for the Reef:
Mitigate: we need to – as per the Paris Agreement – keep average global surface temperature increases to below 2.0°C, and hopefully 1.5°C in the long term. This means we must adopt a pathway that will bring our greenhouse gas emissions to zero over the next few decades. Our leaders must live up to the global agreement that they committed to in Paris at COP21.
Invest: we need to ultimately close our coal mines and stop searching for more fossil fuels. The experts tell us that we must leave 80% of known fossil fuels in the ground. Let’s invest in coral, renewables and the planet, and not in coal, emissions and ecosystem collapse.
Strengthen: we need an urgent and concerted effort to reduce other non-climate change threats to build the resilience of the reef so it can better withstand the impacts of climate change over the coming years.
Integrate: Australian and Queensland governments have begun a process to address declining reef health through the Reef 2050 Long-term Sustainability Plan. This plan has a strong focus on coastal water quality. The 2050 Reef Plan and its resourcing will need to consider climate change – especially given that it is likely to make achieving the objectives of the plan even more challenging and impossible (if no action). Otherwise we run the risk of ending up with a great plan for improving water quality by 2050 but no Great Barrier Reef.
We hope that Sir David Attenborough will help inspire Australians to demand action from their political leaders to ensure that this natural wonder of the world continues to inspire, employ, educate and generate income for generations to come.
It seems fitting to end with Sir David’s closing words with a call to our political leaders and fellow Australians:
Do we really care so little about the earth upon which we live that we don’t wish to protect one of its greatest wonders from the consequences of our behaviours?
After all, it is our Great Barrier Reef – let’s keep it great.
With extensive coral bleaching having been predicted as far back as October last year, Terry Hughes at the ARC Centre of Excellence for Coral Reef Studies convened the National Coral Bleaching Taskforce to document the bleaching, both from the air and at close quarters.
With our survey work still ongoing, a bleak picture is emerging: more than 1,000 km of the Great Barrier Reef shows signs of significant bleaching. In the worst-affected areas, in the GBR’s previously pristine far north, many corals are now expected to die.
At the start of southern summer it was predicted that bleaching would be largely restricted to central and southern parts of the GBR. As it turns out, the first indications of a problem came from scientists working at Lizard Island, in the reef’s remote north. In January, Jodie Rummer of the ARC Centre of Excellence for Coral Reef Studies was studying fish near the island when she noticed that many of the hard corals, soft corals and even clams were starting to bleach.
Shortly thereafter, staff from the Great Barrier Reef Marine Park Authority, undertaking routine surveys in the northern GBR, reported that not only were many of the corals bleached on reefs near Cooktown, but some of the corals had already started dying.
The full extent and severity of the bleaching in the northern GBR became apparent when our colleague Terry Hughes led a team on a series of aerial surveys, similar to those carried out during the 1998 and 2002 GBR bleaching events.
It was expected that these surveys would show that bleaching was restricted to the reefs at and around Lizard Island. But detailed aerial assessments of bleaching severity at 500 reefs have instead shown that 95% of reefs stretching between Cairns and Papua New Guinea have experienced significant coral bleaching. Only four reefs showed no evidence of bleaching.
How do the surveys work?
During aerial surveys, each reef is given a score from 0, indicating no bleaching, to 4, indicating that more than 60% of the corals are bleached. Comparing the results of the latest aerial surveys to those from previous bleaching episodes, it is clear that this bleaching event is far worse.
In 1998 and 2002, fewer than 200 reefs were assigned to the highest bleaching categories (3 or 4), compared with 450 already this year. Moreover, aerial surveys are now continuing on reefs south of Cairns, where bleaching is also being reported.
Extensive aerial surveys are being complemented by in-water surveys by coral biologists. By getting in the water, scientists are better able to ascertain the severity of the bleaching, establish which types of corals have been worst affected, and make predictions about what proportion of the bleached corals are likely to die. The trade-off is that they cannot cover as many locations as an aerial survey.
In places where both aerial and in-water surveys have been conducted, the results match very closely. Near Port Douglas, for example, where aerial surveys revealed many reefs had a score of 4 (greater than 60% bleaching), divers have confirmed that at least 75% of the corals on the shallow reef top are bleached. Similarly, reefs in this region that scored only 2 or 3 from the air show corresponding levels of bleaching in in-water surveys.
The overall pattern
While bleaching surveys are ongoing, a distinct pattern is emerging, whereby the severity of bleaching declines from north to south. Virtually all of the reefs in the GBR’s remote far northern section have been hit very hard. Here, virtually all of the corals, including normally very robust types, are bleached.
Given the severity of the bleaching, we expect that many of the corals in this region will die. This is concerning, given that the GBR’s north was considered “most pristine” in the latest Great Barrier Reef Outlook Report.
Bleached coral near Port Douglas. Cassandra Thompson/ARC Centre of Excellence for Coral Reef Studies, Author provided
Between Cooktown and Cairns – an area of the reef that is particularly important for tourism – the bleaching is much more variable. There are certainly some reefs where up to 90% of the corals are bleached and death rates are expected to be very high. But the extent of bleaching at other nearby reefs is much more moderate, enabling tourists to visit reefs that are still in good condition.
Further south, the extent of bleaching is even more variable and generally less severe. Ironically, the weather disturbance that persisted from Tropical Cyclone Winston, which devastated Fiji in February, helped to cool surface waters over the central and southern GBR, reducing the heat stress suffered by these corals.
Work is continuing to establish the southernmost extent of significant bleaching, but it is clear that a very large stretch (more than 1,000 km) of the GBR has been affected.
While the full extent of the bleaching, as well as the social, ecological and economic impacts, are yet to become apparent, this is undoubtedly the worst known bleaching event on the GBR. The National Coral Bleaching Taskforce will continue to coordinate research throughout 2016 to get a more complete picture of the severity and consequences of this event. The Taskforce is also currently monitoring thermal conditions on Western Australian reefs, which are now at their most critical time for bleaching to occur.
Denialism should not be confused with modern scientific skepticism, which is the challenging of beliefs that are unscientific, irrational or based on insufficient evidence. Instead of denying facts, modern skeptics test claims by analysing whether they are supported by adequate empirical evidence. Denialism is the a priorirejection of ideas without objective consideration.
The philosophical skepticism of the Academic Skeptics and Pyrrhonists in Classical Greece (which was quite different to modern skepticism) consisted of doubting whether there can be any knowledge or facts at all, rather than denying particular facts.
Science denialism is the rejection of basic facts and concepts that are undisputed, well-supported parts of the scientific consensus on a subject, in favour of radical and controversial opinions of an unscientific nature. For example, the term climate change denialist is applied to people who argue against the scientific consensus that the global warming of planet Earth is a real and occurring event primarily caused by human activity.
The term evolution denialist or ‘creationist’ is applied to people who argue against the fact that life on Earth has evolved from earlier forms, instead of having been created by a supernatural being in its current form.
The motivations and causes of denialism include irrationality, religion and self-interest (political, economic or financial), beliefs in conspiracy theories or even defence mechanisms meant to protect the psyche of the denialist against mentally disturbing facts and ideas.