Tag Archives: Climate Change

The Starck truth? Starck naked is more like it…

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So it seems like Walther Starck (with his post graduate training and “professional experience in fisheries biology“) has come running to the rescue with a critique entitled “The Great Barrier Reef prophets of doom”, in response to a recent online piece by Charlie Veron (“The plight of the Great Barrier Reef”):

Although Charlie Veron is a highly respected coral taxonomist many of the statements he made regarding climate change are at best doubtful. Like most biologists he appears to have accepted the “consensus” view of catastrophic climate change without being aware of a vast body of peer reviewed non-biological research that casts doubt on or directly refutes all of the major climatic claims he asserts as unqualified facts.

Good to see Starck again criticising someone else on the lack of peer-reviewed research whilst failing to cite anything in response. Perhaps a reference or two from the peer reviewed scientific literature would help us evaluate the veracity of his claims.

Living, subfossil and fossil corals all indicate that bleaching associated with high temperatures is a common occurrence in reef corals. There is no evidence to indicate that either the frequency or severity of such events has increased.

Huh? Where are the papers to back up those rather sweeping statements?

The fact that Starck responds to Veron’s comment “(Corals)… once survived in a world where carbon dioxide from volcanoes and methane was much higher than anything predicted today. But that was 50 million years ago. The accumulation of carbon dioxide then took millions of years, not just a few decades.” by using the throw-away sentence “Many current reef coral genera survived this event” highlights his complete ignorance of the geological history of reefs. I’m fascinated by statements like these – corals have survived throughout geological history (over 500 million years) and have indeed gone through several extinction events. However, what interests me is that this fact is often used as support for coral longevity. Don’t worry about the loss of entire reef systems (as we are seeing world-wide) – Starck implies that as long as some species of coral within a genera survive, we can ignore the issue. Even though reefs as we know them today (and as Charlie points out) will be long gone – “survival” simply isn’t enough.

It seems like the same old story all over again. As a final point worthy of mention, Walther doesn’t seem to have a full grasp of the scientific literature:

Although there is credible evidence for past carbon dioxide levels greater than any increase we may experience before all fossil fuel is consumed there is no evidence to indicate that past such increases took place much slower than the present one or that slower or faster would make any real difference

Starck again confuses the rate of change with the limit of change. I would direct him to Table 1 in our recent Science article. Here we calculated the rate of change over the past 420,000 years and found that the rate of change over the past 136 years was up to 1000 fold higher any previous rate of change. Stands to reason given that it took 30,000 years for atmospheric carbon dioxide to change by 100 ppm in the past, and we have just changed the atmosphere by a similar amount in only 100 years!

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Coral reefs – a “Canary in a Coal Mine”

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http://blip.tv/play/AbXFHgA

“In this episode of MicrobeWorld Video marine scientists Ove Hoegh-Guldberg, Ph.D., chair of marine studies at the University of Queensland in Brisbane, Australia, and Kiho Kim, Ph.D., director of the environmental studies program at American University, explain the important relationship between microbes and corals, and how this delicate symbiosis that sustains life on and around reefs is facing numerous threats from human interactions to global climate change. In addition, Tundi Agardy, Ph.D., founder and executive director of Sound Seas, discusses the need for public policy and community-based conservation efforts that may help stave off the degradation of these vital ocean ecosystems.According to a 2004 report issued by the World Wildlife Fund, 24% of the world’s reefs are under imminent risk of collapse through human pressures; and a further 26% are under a longer term threat of collapse. If nothing is done to protect these resources, many scientists estimate that reefs around the West Indies in the Caribbean will be gone by 2020, while the Great Barrier Reef may only last for another three decades.”

“The holy crap factor” – a note from Caspar Henderson

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For a while I had a T-shirt from The Onion which read Holy Sh*t! Man Walks on F*cking Moon. It made a lot of us laugh (and it was almost certainly stolen by a man called Pete Lucas. Pete, if you’re out there, please tell me this isn’t so).

Related, but different, is what Mitchell Anderson, blogging a paper by Werner Kurz et al in Nature, calls the holy crap factor (Anderson is Canadian, hence the politeness).

Mistah Kurz, he bring bad news: in this case that warming in western Canada, likely to be anthropogenic, has unleashed a chain of events that will release close to one billion tonnes of carbon into the atmosphere by 2020. The ‘holy crap’ part is that this may be just one several unplanned accelerations of climate change by human agency.

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Coral adaptation in the face of climate change – response by Hoegh-Guldberg et al

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We certainly hope that Baird and Maynard are right and that in the coming years corals will exhibit an adaptive capability that they have not yet exhibited in situ or in the laboratory. At this point, however, it appears unlikely.
As Baird and Maynard point out, the coral genera Acropora and Pocillopora have generation times that are short (several years) relative to the generation times of other corals. The majority of coral generation times, however, are still long (decades) relative to the accelerating pace of climate change, throwing doubt on the scope of most coral species for rapid adaptation (1).

Corals, like other organisms, can also modify the risk of coral bleaching over the short term through physiological acclimation (2). Acclimation, however, as with any phenotypic change, is limited. In the same vein, corals that form symbioses with more than one variety of dinoflagellate can shift their populations so that they are dominated by their more thermally tolerant dinoflagellate genotypes during thermal stress. Unfortunately, these short-lived changes have not yet resulted in the novel host-symbiont combinations that will be required for survival in the challenging temperatures and acidities of future oceans under rising atmospheric carbon dioxide.

It is important not to confuse genetic adaptation with the increased average thermal tolerance observed for some coral communities over the past 25 years, which has occurred largely because thermally sensitive species have died out, leaving robust species behind (3). Equally important is the lack of evidence that corals have the capacity to either acclimate or adapt to falling aragonite saturation states. It seems unlikely that genetic adaptation will solve the problems of global change facing corals. Indeed, paleontological evidence indicates that calcifying marine organisms including corals suffered a protracted period of absence after large and rapid changes in atmospheric carbon dioxide associated with the Permian-riassic extinction event (4, 5). It took millions of years for these organisms and ecosystems to recover.

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Coral adaptation in the face of climate change – Baird & Maynard

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cover.gifIn their Review, “Coral reefs under rapid climate change and ocean acidification” (14 December 2007, p. 1737), O. Hoegh-Guldberg et al. present future reef scenarios that range from coral-dominated communities to rapidly eroding rubble banks. Notably, none of their scenarios considers the capacity for corals to adapt. The authors dismiss adaptation because “[r]eef-building corals have relatively long generation times and low genetic diversity, making for slow rates of adaptation [relative to rates of change].” We think the possibility of adaptation deserves a second look.
Many features of coral life histories, such as extended life spans, delayed maturation, and colony fission, do result in long generation times (1) [some between 33 and 37 years (2)]. However, other corals, such as many species of Acropora and Pocillopora, mature early, grow rapidly, and suffer whole-colony mortality, as opposed to colony fission, after mechanical disturbances (3) and thermal stress (4). The life histories of these ecologically important and abundant species suggest an underappreciated capacity to adapt rapidly to changing environments.

Repeated bleaching episodes in the same coral assemblages and the increasing scale and frequency of coral bleaching have been cited as evidence that corals have exhausted their genetic capacity to adapt to rising sea surface temperatures (5). However, comparisons of the rates of mortality within populations among bleaching events are not available. Without these data, it is not possible to assess whether the adaptive response has been exhausted. Indeed, the effects of temperature and acidification on even the most basic vital rates in corals, such as growth, mortality, and fecundity, are largely unknown, as are the physiological trade-offs among these traits. Consequently, the sensitivity of population growth to climate-induced changes in vital rates remains almost completely unexplored [but see (6)]. In the absence of long-term demographic studies to detect temporal trends in life history traits, predicting rates of adaptation, and whether they will be exceeded by rates of environmental change, is pure speculation. Indeed, where such data are available for terrestrial organisms they demonstrate that contemporary evolution in response to climate change is possible (7).

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Australian attitudes towards climate change: putting words into action.

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The Climate Institute’s Climate of the Nation has released a report that shows that the attitudes of Australians has shifted from 5 years ago and that climate change is a primary concern. What is curious is that the Rudd government hasn’t convinced us that real and effective action will be possible..

"Australian attitudes towards climate change have crystallised into solid support for action, new research shows. But, equally, there is widespread scepticism about the ability of major political parties to deliver the necessary action. The Climate Institute’s Climate of the Nation report details the attitudes of Australians since the November federal election.

"In the aftermath of the world’s first climate change election, public concern and hunger for action remains high," the institute’s chief executive John Connor said.

"The majority of Australians (52 per cent) are unable to discern between the two major parties on climate change, meaning political brand ownership of climate leadership remains up for grabs." (Read more)

Meanwhile, federal environment minister Peter Garrett has decided against a national levy on plastic bags, despite Victoria introducing a levy, and South Australia banning plastic bags from 2009

"What we’ve decided today is that there will not be a national mandated charge on plastic bags in checkouts but we do want to see increased action to reduce plastic bag use in the community," Mr Garrett said.

"We’ve identified the need for an urgent working group to be established between government and industry to look at making sure retailers are exploring all the options that they have in front of them to increase the use of the green recycle bags and to lessen the use of plastic bags."

South Australian Environment Minister Gail Gago said she was "deeply disappointed" there had not been national agreement to phase out plastic bags or introduce a charge, but her state would push ahead with a ban regardless.

"After six years of the council, we’re still unable to come to a nationally consistent approach," Ms Gago said. (Read more)

Who’s putting the “political” in climate science, now? – a note from Philip Machanick

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Below is a excellent response from a fellow blogger Philip Machanick over at Opinionations regarding the recent article in The Australian newspaper by Don Aitken (social scientist, retired Vice-Chancellor and President of University of Canberra, in addition to being one of Senator Inhofe’s “concerned scientists“) – why this recieved front page coverage in such a prominent newspaper is beyond me, and Philip does an great job of debunking the rhetoric:

“On 9 April, The Australian published an article titled “Good science isn’t about consensus” on its front page.The New York Times‘s masthead motto is “All the news that’s fit to print.” The Australian‘s might as well be “All the news that fits our prejudice.”

Don Aitkin is of course entitled to his opinion (though as the late Senator Moynihan reminded us, he is not entitled to his own facts). The paper could have run his piece as an op ed on the inner pages (though for what purpose, I don’t know). But by running it with the prominence they have, you have to wonder at their motivation. Don Aitkin is a political scientist, no doubt eminent in his field. But no one can pretend he is an authority on climate science. What’s more, his article contains nothing of any novelty. So what purpose can there be in not only publishing the article, but in giving it the prominence of a page 1 placement? All I can think of is that The Australian wishes to continue to stoke controversy — whether to generate circulation (which doesn’t work with me, I stopped buying the paper) or to pursue its own agenda on climate science.

However, since they have done this, and in addition, posted a lengthier paper (an address he gave to the Planning Institute of Australia), his views demand rebuttal. Here it is, based on the lengthier paper.

  • Arguing about “consensus” is silly. There was a consensus before Einstein’s time that Newton had the Laws of Physics stitched up. Einstein found a more general theory. “Consensus” in science is not a deep concept — just a way of expressing the fact that most scientists do not see the point in arguing over something that has been shown to be valid, and no one has successfully invalidated. There was a similar “consensus” about the link between tobacco and cancer, which the relevant industry attacked vigorously, using similar language to the anti-AGW movement. That consensus remains to be overturned, despite the fact that we still have a lot to learn about the mechanisms of cancer.
  • He claims that he is “presently agnostic about the central Anthropogenic Global Warming…proposition” but this is not borne out by his article, which dwells on arguments against AGW. To quote Monty Python, that’s not debate, it’s contradiction.
  • The “panicky media mood” he talks about is no reason to trash the science, rather to be skeptical about the quality of science journalism in popular media. There was a similarly panicky media mood about global cooling in the 1970s (he quotes Newsweek further on) but if you actually search the scientific literature, there was very little basis in science for this. I don’t think you will find a “panicky mood” if you read Science or Nature. A paper has been published showing that 7 papers in the 1970s predicted cooling, compared with 42 predicting warming. The cooling papers attracted only 12% of the citations counted. In other words, even in the 1970s, the evidence available at the time — Newsweek and other popular media notwithstanding — was that warming was more supportable than cooling.
  • Einstein and Feynman on refutation and uncertainty in science: the anti-AGW movement can be accused of a higher degree of certainty with considerably less evidence on their side. Read Bob Carter’s polemics. Is there a hint in any of his writing the he could be wrong? On the contrary, there is a bellicose certainty in his writing which I have not found in the scientific literature — which I find odd from a scientist of his experience (here’s a classic example).

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Coral reef fish act as “lawnmowers” in the fight against climate change

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BBC News, 20th March

A healthy fish population could be the key to ensuring coral reefs survive the impacts of climate change, pollution, overfishing and other threats. Australian scientists found that some fish act as “lawnmowers”, keeping coral free of kelp and unwanted algae. At a briefing to parliamentarians in Canberra, they said protected areas were rebuilding fish populations in some parts of the Great Barrier Reef.

Warming seas are likely to affect the reef severely within a few decades. Pollution is also a growing problem, particularly fertilisers that wash from agricultural land into water around the reef, stimulating the growth of plants that stifle the coral. The assembled experts told parliamentarians that fish able to graze on invading plants played a vital role in the health of reef ecosystems.
“The Great Barrier Reef is still a resilient system… and herbivorous fish play a critical role in that regenerative capacity, by keeping the dead coral space free of algae, so that new juvenile coral can re-establish themselves,” said Professor Terry Hughes from James Cook University in Townsville. His research group has conducted experiments which involved building cages to keep fish away from sections of reef. They found that three times as much new coral developed in areas where the fish were present as in the caged portions.

Parrotfish in particular use their serrated jaws to scrape off incipient algae and plants. More recently, his team has also identified the rabbit fish – a brown, bland-looking species – as a potentially important harvester of seaweed. “So managing fisheries can help to maintain the reef’s resilience to future climate change,” he said. In recent years, Marine Protected Areas have been set up along the Great Barrier Reef in order to provide sanctuaries where fish and other marine creatures can grow and develop.

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Has the Great Barrier Reef got a future?

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Once I would have thought that a ridiculous question. Yet today, if we assemble all the best science we have, the answer can at best be “maybe”.

It may seem preposterous that the greatest coral reef in the world – the biggest structure made by life on Earth – could be seriously (I mean genuinely seriously) threatened by climate change. The question itself is probably already relegated in your mind to a ‘here-we-go-again’ catch-bag of greenie diatribe about the state of our planet. This view is understandable given that even a decade ago, there were many scientists who had not yet come to grips with the full implications of climate change.

Very likely you have a feeling that dire predictions about anything almost always turn out to be exaggerations. What you really think is: OK, where there’s smoke there’s fire, so there’s probably something in this to be worried about, somewhere. But, it won’t be as bad as those doom-sayers are predicting. When I started writing “A Reef in Time”, I knew that climate change was likely to have serious consequences for coral reefs, but even I was shocked to the core by what all the best science that existed was saying. In a long phase of personal anguish I turned to specialists in many different fields of science to find anything that might suggest a fault in my own conclusions. No luck. The bottom line remains: the GBR can indeed be utterly trashed in the lifetime of today’s children. That certainty is what motivates me to broadcast this message as clearly, as accurately and, yes, as loudly, as I can.

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“Corals kick out housemates that can’t stand the heat”

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New Scientist, 19th March 2008

When the going gets hot, corals can kick out heat-sensitive strains of symbiotic algae and take on a type that can withstand higher temperatures. This could mean certain reefs will be less susceptible to global warming than had been thought.

Like most other hard coral species, Acropora millepora, which is common in the Indo-Pacific region, relies primarily on microscopic algae for its nutrient supply. During sustained periods of high temperatures, heat stress causes the algae – which live within the coral – to pump out oxygen free radicals, which damage coral tissue. The coral is then forced to eject the algae – a phenomenon known as bleaching. It’s a lose-lose situation: the algae loses its home, and the coral its food supply. In some cases, it can lead to the coral starving to death.

Alison Jones of the Australian Institute of Marine Science, Townsville, and colleagues studied A. millepora living off Miall Island, part of the Keppel Island group in the southern inshore Great Barrier Reef, before and after a mass bleaching event in early 2006.

Heatwave effect

During this event, sea temperatures around Miall reef hit 30.2 °C for 30 days. This compares with an average for the season of 27.1 °C. Corals in this region start to show signs of heat stress when sea temperatures stay above 28.5 °C for more than 25 days, or above 29.5 deg C for longer than five days.

When the team sampled the coral colonies in 2003, they found that 93.5 % harboured mostly type C2 algae, which is relatively heat-sensitive. The remainder was formed of type D algae, which is heat-tolerant. After sweltering in the heat of 2006, 37 % of these colonies had died. By contrast, only 8 % of the colonies that had harboured mostly type D had died.

In follow-up work three months after the bleaching event, the team also found that nearly three-quarters of the colonies that had survived and that had originally harboured mostly C2 had switched to contain mostly type D – making them less susceptible to a bleaching event in future. These surviving colonies had initially had low background levels of D.

“This is great news,” says team member Ken Berkelmans. “It seems coral communities are probably far more adaptable to changing conditions than we’ve previously given them credit for.”

Short-lived adaptation

However, these findings so far relate to only one species in one location. And six months after the mass bleaching, the colonies did show some drift back towards C2, which allows them to grow faster than D.

Ove Hoegh-Guldberg, a leading coral biologist at the University of Queensland, Brisbane, says the findings are very interesting, in that they demonstrate a way in which corals can acclimatise to warmer temperatures – to an extent. However, he is cautious about what the results might mean in the long run, as type D provides the coral with only about an extra 1 to 1.5 °C of heat tolerance.

“After changing to D, corals don’t really have any other options – and the benefits of D will eventually be overwhelmed by climate warming,” he says.