July 02, 2008
Ocean Acidification: Photographs from Bob Halstead and a Note from Floor Anthoni
Hi Jennifer,
The shallows near Dobu Island off Papua and New Guinea have active underwater fumaroles pumping out virtually pure CO2. The sea grass is extraordinarily lush and healthy and there is very healthy coral reef a few metres away.
May 2008 in PNG at Dobu Island in the D'Entrecasteaux Group
May 2008 in PNG at Dobu Island in the D'Entrecasteaux Group
Both photos show bubbles of CO2 which continually flow. I collected samples of gas years ago for a vulcanologist and he reported back to me that it was "virtually pure CO2".
Unfortunately the water had poor visibility the day I shot the pictures, but it is often clear.
Bob Halstead
www.halsteaddiving.com
And also...
Dear Jennifer,
I have recently updated my article about ocean acidification by reviewing two recent studies.
http://www.seafriends.org.nz/issues/global/acid2.htm
I thought it may interest you.
Dr J Floor Anthoni
Director Seafriends Marine Conservation and Education Centre
http://www.seafriends.org.nz/
Posted by jennifer at 12:52 PM | Comments (69) | TrackBack
May 09, 2008
The Starck Truth about The Great Barrier Reef
Walter Starck has an excellent 4 page rebuttal of a greenhouse doom and gloom article by Charlie Vernon over at On Line Opinion. Vernon's article entitled, 'The plight of the Great Barrier Reef:' claims that by 2050 the Great Barrier Reef will be unrecognisable: "Bacterial slime, largely devoid of life, will be everywhere."
Dr J.E.N. (Charlie) Veron is Former Chief Scientist at the Australian Institute of Marine Science and an author based in Townsville Queensland.
Walter Starck's response is entitled, 'The Great Barrier Reef and the prophets of doom:' "Even the more extreme model projections only depict tropical oceanic warming still well within the limits that thriving reefs tolerate." Dr Walter Starck has a PhD in marine science including post graduate training and professional experience in fisheries biology. He is the editor and publisher of Golden Dolphin, a quarterly publication on CD focusing on diving, underwater photography and the ocean world.
Posted by Paul at 04:37 AM | Comments (16) | TrackBack
March 25, 2008
Coral Re-growth on the Great Barrier Reef: A Note from Bob Halstead
In July 2002 I was helping teach an underwater photography course for students at James Cook University. Day trips to the outer barrier were organised from Port Douglas. On the reef I mostly saw dead coral smothered with rafts of brown algae, and struggled to find any living invertebrates for the students to photograph. It was depressing.
However, in October 2007 I made a live-aboard cruise up the reef, and a day trip out of Cairns, which cheered me up enormously. All along the outer reef there were dramatic signs of coral regeneration. There were reefs covered with small plate corals of various species, and other corals, which looked, from my experience in Papua New Guinea, to be of the order of 1-3 years growth. Here are some of the photographs I took.
http://www.halsteaddiving.com/
http://www.halsteaddiving.com/
http://www.halsteaddiving.com/
http://www.halsteaddiving.com/
http://www.halsteaddiving.com/
http://www.halsteaddiving.com/
Bob Halstead
http://www.halsteaddiving.com/
Posted by jennifer at 08:17 PM | Comments (6) | TrackBack
March 22, 2008
Fish Key to Reef Survival
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.
The Great Barrier Reef is worth about six billion Australian dollars (US$5.5bn; £2.8bn) to the national economy, primarily through tourism and fishing.
BBC Website: 'Fish key to reef climate survival '
Posted by Paul at 12:57 AM | Comments (2) | TrackBack
February 11, 2008
'Ocean Thermostat' Could Protect Some Coral Reefs
A new study suggests that some coral reefs could be protected from bleaching by a natural 'ocean thermostat' that regulates sea surface temperatures in the western pacific warm pool.
The paper was published in GRL on 9th February:
GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L03613, doi:10.1029/2007GL032257, 2008
Joan A. Kleypas, National Center for Atmospheric Research, Boulder, Colorado, USA
Gokhan Danabasoglu, National Center for Atmospheric Research, Boulder, Colorado, USA
Janice M. Lough, Australian Institute of Marine Science, Townsville, Queensland, Australia
Abstract:
Several negative feedback mechanisms have been proposed by others to explain the stability of maximum sea surface temperature (SST) in the western Pacific warm pool (WPWP). If these “ocean thermostat” mechanisms effectively suppress warming in the future, then coral reefs in this region should be less exposed to conditions that favor coral reef bleaching. In this study we look for regional differences in reef exposure and sensitivity to increasing SSTs by comparing reported coral reef bleaching events with observed and modeled SSTs of the last fifty years. Coral reefs within or near the WPWP have had fewer reported bleaching events relative to reefs in other regions. Analysis of SST data indicate that the warmest parts of the WPWP have warmed less than elsewhere in the tropical oceans, which supports the existence of thermostat mechanisms that act to depress warming beyond certain temperature thresholds.
The study is also reported on the BBC website: 'Ocean thermostat can save coral'
Jen reminded me about the OLO article by Peter Ridd: 'The Great Great Barrier Reef Swindle'
"The scientific evidence about the effect of rising water temperatures on corals is very encouraging. In the GBR, growth rates of corals have been shown to be increasing over the last 100 years, at a time when water temperatures have risen. This is not surprising as the highest growth rates for corals are found in warmer waters. Further, all the species of corals we have in the GBR are also found in the islands, such as PNG, to our north where the water temperatures are considerably hotter than in the GBR. Despite the bleaching events of 1998 and 2002, most of the corals of the GBR did not bleach and of those that did, most have fully recovered.
Of course, some corals on the Queensland coast are regularly stressed from heat, viz. the remarkable corals of Moreton Bay near Brisbane which are stressed by lack of heat in winter. A couple of degrees of global warming
would make them grow much better."
Posted by Paul at 05:57 PM | Comments (57) | TrackBack
October 05, 2007
More on Corals from This Week's Science Magazine
A World with Corals: What Will It Take?
...........The measures required to limit climate change can seem an eternity away to coastal communities left to deal with the consequences. Yet, since the 1997-98 mass bleaching--an unforgiving global event that destroyed 16% of the world's coral reefs--practitioners and scientists have worked to identify meaningful actions that can promote reef survival in the face of climate change.........
Although the current greenhouse trajectory is disastrous for coral reefs and the millions of people who depend on them for survival, we should not be lulled into accepting a world without corals. Only by imagining a world with corals will we build the resolve to solve the challenges ahead. We must avoid the "game over" syndrome and marshall the financial, political, and technical resources to stabilize the climate and implement effective reef management with unprecedented urgency.
Modern coral reefs are built primarily by scleractinian corals, which arose in the Triassic after the Permian extinction. Today, all of these corals form skeletons of aragonite, and this composition has been thought to be typical of fossil scleractinians as well. Stolarski et al. (p. 92) now have identified a Cretaceous scleractinian coral with a primary calcite skeleton. The fine preservation of internal structures and the Mg and Sr chemistry show that the calcite is primary, not diagenetic. This result tightens the evolutionary connection between these corals and rugose corals, which formed calcite skeletons but were eliminated in the Permian extinction. These results suggest that corals may be able to alter their biochemistry in response to changes in seawater chemistry.
A Cretaceous Scleractinian Coral with a Calcitic Skeleton
Jarosaw Stolarski,1* Anders Meibom,2 Radosaw Przenioso,3 Maciej Mazur4
It has been generally thought that scleractinian corals form purely aragonitic skeletons. We show that a well-preserved fossil coral, Coelosmilia sp. from the Upper Cretaceous (about 70 million years ago), has preserved skeletal structural features identical to those observed in present-day scleractinians. However, the skeleton of Coelosmilia sp. is entirely calcitic. Its fine-scale structure and chemistry indicate that the calcite is primary and did not form from the diagenetic alteration of aragonite. This result implies that corals, like other groups of marine, calcium carbonate–producing organisms, can form skeletons of different carbonate polymorphs.
Posted by Paul at 05:38 PM | Comments (3) | TrackBack
October 02, 2007
A Note to Ian Mott on Global Warming And Coral Reefs
Dear Ian,
The Center for Biological Diversity contends that staghorn coral and elkhorn coral are "the first, and to date only, species listed under the Endangered Species Act due to threats from global warming." Kieran Suckling, the policy
director of the Center, "We think this victory on coral critical habitat actually moves the entire Endangered Species Act onto a firm legal foundation for challenging global-warming pollution."
The Center for Science & Public Policy has published a report taking a closer look at the scientific evidence, which reveals that the impact of global warming on the overall health of coral species is likely to be positive--towards increased species diversity and richness and habitat expansion--and there is evidence that these changes are already underway.
The hope that this endangered species designation will somehow become a tool for global warming legislation is grossly misplaced. Global warming will likely be a benefit to elkhorn and staghorn corals, especially along the
Florida coast where increasing ocean temperatures should encourage coral reef development further and further northward.
The report is available at http://ff.org/images/stories/sciencecenter/coral_reefs_and_global_warming.pdf
Paul Georgia, Ph.D.
Center for Science & Public Policy
Frontiers of Freedom
Posted by jennifer at 10:03 AM | Comments (2) | TrackBack
August 21, 2007
On the Decline of Coral Reef Ecosystems: A New Paper by Peter Ridd
The supposedly already-degraded state of coral reef ecosystems is sometimes claimed to be a reason why anthropogenic global warming will have a major impact on the reefs, i.e. they are already close to extinction and can easily be tipped over the edge.
A recent paper** by Peter Ridd challenges the methodology used to conclude that the outer and inner Great Barrier Reef (GBR) are already 28% and 36% respectively, down the path towards ecological extinction.
I've uploaded the full paper, with permission from the author, here: http://jennifermarohasy.com/data/Ridd_Energy%20n%20Environment.pdf
---------------------
** A CRITIQUE OF A METHOD TO DETERMINE LONG-TERM DECLINE OF CORAL REEF ECOSYSTEMS
by Peter V. Ridd. Reprinted from ENERGY & ENVIRONMENT, VOLUME 18 No. 6 2007
Posted by jennifer at 05:02 PM | Comments (3) | TrackBack
July 19, 2007
The Great Great Barrier Reef Swindle: A Note from Peter Ridd
Those of you who watched the ABC’s presentation of The Great Global Warming Swindle might not have been convinced by the arguments challenging the conventional wisdom that carbon dioxide is responsible for global warming. However, it should be apparent that scientists and politicians such as Al Gore, who have been telling us that the science is unquestionable on this issue, have been stretching the truth. It seems that there are some good reasons to believe that we may have been swindled.
Closer to home, there is a swindle by scientists, politicians and most green organisations regarding the health of the Great Barrier Reef (GBR). We are told that the reef is a third of the way to ecological extinction, is being smothered by sediments, is polluted by nutrients and pesticides, and is being cooked by global warming. Some scientists and organisations give the reef only a couple of decades before it is finished.
In the light of all this dismal news comes a new study by Scientists from the Australian Institute of Marine Science (AIMS) which indicates that the corals are more tolerant to rising waters temperatures than first thought by most people.
Under conditions of extremely high water temperature, corals expel the symbiotic algae called zooxanthelae that reside within the polyp making them appear bleached white. Some coral die from this bleaching and there have recently been some major mass bleaching events in the Great Barrier Reef and around the world, particularly in 1998 and 2002. The AIMS work shows that the corals can adapt to rising water temperatures by using strains of zooxanthelae that make them tolerant to higher temperatures.
In biological circles, it is common to compare coral reefs to canaries, i.e. beautiful and delicate organisms that are easily killed. The analogy is pushed further by claiming that, just as canaries were used to detect gas in coal mines, coral reefs are the canaries of the world and their death is a first indication of our apocalyptic greenhouse future. The bleaching events of 1998 and 2002 were our warning. Heed them now or retribution will be visited upon us.
In fact a more appropriate creature with which to compare corals would be cockroaches - at least for their ability to survive. If our future brings us total self-annihilation by nuclear war, pollution or global warming, my bet is that both cockroaches and corals will survive.
Their track-record is impressive. Corals have survived 300 million years of massively varying climate both much warmer and much cooler than today, far higher CO2 levels than we see today, and enormous sea level changes. Corals saw the dinosaurs come and go, and cruised through mass extinction events that left so many other organisms as no more than a part of the fossil record.
Corals are particularly well adapted to temperature changes and in general, the warmer the better. It seems odd that coral scientists are worrying about global warming because this is one group of organisms that like it hot. Corals are most abundant in the tropics and you certainly do not find fewer corals closer to the equator. Quite the opposite, the further you get away from the heat, the worse the corals. A cooling climate is a far greater threat.
The scientific evidence about the effect of rising water temperatures on corals is very encouraging. In the GBR, growth rates of corals have been shown to be increasing over the last 100 years, at a time when water temperatures have risen. This is not surprising as the highest growth rates for corals are found in warmer waters. Further, all the species of corals we have in the GBR are also found in the islands, such as PNG, to our north where the water temperatures are considerably hotter than in the GBR. Despite the bleaching events of 1998 and 2002, most of the corals of the GBR did not bleach and of those that did, most have fully recovered.
Of course, some corals on the Queensland coast are regularly stressed from heat, viz. the remarkable corals of Moreton Bay near Brisbane which are stressed by lack of heat in winter. A couple of degrees of global warming would make them grow much better.
Even the GBR has seen massive changes in its comparatively short life. Eighteen thousand years ago, the GBR did not exist as water levels were about 100m lower than today. At that time, the Australian coast was about 100km from its present position, and the small hills upon which the reefs were to form dotted a broad and flat coastal plain that would become the GBR lagoon. When the sea level started to rise at the end of the ice age, the coast eroded at a phenomenal rate. The Aboriginal people living on these coastal plains lost land at a rate of about 50m each year as they witnessed the birth of one of the natural wonders of the world.
The reef was born in conditions that most biologists would regard as horrific for corals and far worse than what most of the present GBR would see: rising temperatures, high water turbidity due to the erosion, high nutrient concentrations due to erosion and the closer proximity of river mouths, rising CO2 concentrations, and rapidly rising sea levels (10mm per year). These are all factors presently regarded as threats to the GBR.
A few millennia later, Aboriginal people were to witness the greatest loss of coral ever seen by humans in Australia, for about 5,000 years ago, whilet civilisations were being born around the world, the sea level of eastern Australia started to fall. The coral reefs that had grown rapidly upwards to the low tide level were now exposed to the air and sun during spring tides. They died and formed the extensive dead areas called reef flat that make up a large proportion of many reefs in the GBR. It is ironic that if we see a modest sea level rise of one metre due to global warming, these dead areas of reef will explode into life, potentially doubling the coral cover. Sea level rise will be bad for Bangladesh and Venice but it will be good for the GBR.
Other threats are also overstated. Studies have shown that the quantity of sediment in rivers’ plumes that wash out into the lagoons is much less than sediment that is resuspended from the seabed every time the south-easterly trade winds blow. Pollution due to nutrients is also probably restricted to a few reefs close to a couple of river mouths as the rest of the lagoon receives relatively small nutrient loads from rivers compared to other sources, and the water is rapidly flushed to the Coral Sea.
Fishing pressure is very limited. The coast adjacent to the GBR contains about half a million people compared with 50 million for the similarly sized Caribbean reefs. Most Queenslanders never visit the reef and do not use it as a significant food source unlike most other reefs around the world. The northern 1,000 kilometres of the reef has a population that can be counted in 100’s. It has been barely touched by mankind.
With the exception of Antarctica, I challenge anyone to name an ecosystem better preserved than the GBR. The sheer lack of people pressure on this huge system, and its distance from the coast has saved the GBR from the fate that has befallen the Caribbean and other areas. It did not suffer the equivalent of land clearing for agriculture, cities, dams and roads. It does not have problems with infestations of noxious weeds and feral animals such as cats and cane toads, or the mass species extinctions of the Australian land.
Apart from a reduction in turtles and dugongs, it is doubtful that Captain Cook would notice any difference to the GBR if he sailed up this coast again. Pity we cannot say the same about the land that he visited. Whereas the coral reef that he struck near Cooktown is alive and healthy, the land around Botany Bay would be unrecognisable.
So why have we been swindled into believing this almost pristine system is just about to roll over and die when it shows so few signs of stress. There are many reasons and processes that have caused this and some of them are the same as why we should all be more than a little sceptical about the hypothesis that CO2 is causing global warming.
The first reason is that there is some very bad science around. Second, a mainly biological oriented scientific community seems to take little heed of the geological history of corals. Third, we have many organisations and scientists that rely for funding on there being a problem with the GBR. Most grant applications on the GBR will mention at some stage that a motivation for the work is the threat to which it is exposed. I confess that I do this in all my applications - it’s the way the game works.
Why does a scientist and environmentalist such as myself worry about a little exaggeration about the reef. Surely it’s better to be safe than sorry. To a certain extent it is, however, the scientist in me worries about the credibility of science and scientists. We cannot afford to cry wolf too often or our credibility will fall to that of used car salesmen and estate agents - if it is not there already. The environmentalist in me worries about the misdirection of scarce resources if we concentrate on “saving” a system such as the GBR. Better we concentrate on weeds and overpopulation and other genuine problems.
So I’m thinking of asking Martin Durkin to come over to Australia and do another show called The Great Great Barrier Reef Swindle. I’d have to make sure he got all his graphs right and did not talk to anybody who thought smoking didn’t cause cancer, but I reckon he could put a very compelling case that the GBR is in great shape and that there is little to fear, especially relative to other environmental issues, such as overpopulation and invasive species.
Peter Ridd is a Reader in Physics at James Cook University specialising in Marine Physics. He is also a scientific adviser to the Australian Environment Foundation.
This article was first published by On Line Opinion and is republished here with permission from the author.
Posted by jennifer at 10:03 AM | Comments (64) | TrackBack
April 08, 2007
Latest IPCC Climate Change Report
It was all over ABC news yesterday that Australia’s magnificent Great Barrier Reef is in "real danger of disappearing in 20 years"
The journalist, Elizabeth Jackson, was extrapolating from a new United Nation’s 23-page summary of a report on climate change.
This is the second summary report from the United Nation's this year with the first summary report released in Paris on the 2nd February (blog post and comment on first report here).
The new summary report doesn't say the reef will disappear at all, but it does paint a bleak picture. There only appears to be one reference to the Great Barrier Reef and the text reads:
"Significant loss of biodiversity is projected to occur by 2020 in some ecologically-rich sites including the Great Barrier Reef and Queensland Wet Tropics. Other sites at risk include Kakadu wetlands, south-west Australia, sub-Antarctic islands and the alpine areas of both countries."
There is also comment more generally about reefs including:
“Increases in sea surface temperature of about 1 to 3°C are projected to result in more frequent coral bleaching events and widespread mortality, unless there is thermal adaptation or acclimatisation by corals. [emphasis added]
“Mangroves and coral reefs are projected to be further degraded, with additional consequences for fisheries and tourism.
“For example, current stresses on some coral reefs include marine pollution and chemical runoff from agriculture as well as increases in water temperature and ocean acidification.
“As a consequence of intense tropical cyclone activity: damage to coral reefs.” [end of quotes]
I’m still not convinced destructive fishing practices and pollution aren’t a greater risk to the world’s reefs than climate change as detailed in my controversial opinion piece written for The Australian some months ago.
The new summary sets out all the key policy-relevant findings of the Fourth Assessment of Working Group II of the Intergovernmental Panel on Climate Change (IPCC).
The Assessment is of, “current scientific understanding of impacts of climate change on natural, managed and human systems, the capacity of these systems to adapt and their vulnerability. It builds upon past IPCC assessments and incorporates new knowledge gained since the Third Assessment”.
While much of the report is about what ‘could’ happen to the environment given global warming. It is interesting to note what is included in the section on current knowledge about observed impacts of climate change on the natural environment:
“With regard to changes in snow, ice and frozen ground (including permafrost), there is high confidence that natural systems are affected. Examples are:
• enlargement and increased numbers of glacial lakes;
• increasing ground instability in permafrost regions, and rock avalanches in mountain regions;
• changes in some Arctic and Antarctic ecosystems, including those in sea-ice biomes, and also
predators high in the food chain.
Based on growing evidence, there is high confidence that the following types of hydrological systems are being affected around the world:
• increased run-off and earlier spring peak discharge in many glacier- and snow-fed rivers;
• warming of lakes and rivers in many regions, with effects on thermal structure and water quality.
There is very high confidence, based on more evidence from a wider range of species, that recent warming is strongly affecting terrestrial biological systems, including such changes as:
• earlier timing of spring events, such as leaf-unfolding, bird migration and egg-laying;
• poleward and upward shifts in ranges in plant and animal species.
Based on satellite observations since the early 1980s, there is high confidence that there has been a trend in many regions towards earlier ‘greening’5 of vegetation in the spring linked to longer thermal growing seasons due to recent warming.
There is high confidence, based on substantial new evidence, that observed changes in marine and freshwater biological systems are associated with rising water temperatures, as well as related changes in ice cover, salinity, oxygen levels and circulation.
These include:
• shifts in ranges and changes in algal, plankton and fish abundance in high-latitude ocean;
• increases in algal and zooplankton abundance in high-latitude and high-altitude lakes;
• range changes and earlier migrations of fish in rivers.
The uptake of anthropogenic carbon since 1750 has led to the ocean becoming more acidic with an average decrease in pH of 0.1 units [IPCC Working Group I Fourth Assessment]. However, the effects of observed ocean acidification on the marine biosphere are as yet undocumented.” [end of quote]
There is no specific reference to coral reefs in the "observed impacts" section. The comment that there is no evidence of ocean acidification affecting the marine biosphere presumably includes no impact on coral reefs.
In summary the report, like most climate change reports from the United Nations, includes relatively unspectacular observed impacts, is big on all the bad things that could happen, and the Australian media blow this out of all proportion, this time including comment that the Great Barrier Reef could disappear in 20 years.
Posted by jennifer at 04:32 PM | Comments (52) | TrackBack
Pacific Island Rises Up Out of the Ocean
There has been widespread concern that rising sea levels from global warming will swamp Pacific Islands. (Remember the blog post by Ian Mott lambasting the ABC for confusing sinking islands with rising sealevels?)
Then along comes a seismic jolt unleashing a tsunami and, acording to ABC news, an entire island is lifted three metres out of the sea:
"In an instant, the grinding of the Earth's tectonic plates in the 8.0 magnitude earthquake on Monday forced the island of Ranongga up three metres.
Submerged reefs that once attracted scuba divers from around the globe lie exposed and dying after the quake raised the mountainous landmass, which is 32 kilometres long and eight kilometres wide."
Read the complete article here: http://www.abc.net.au/news/newsitems/200704/s1892185.htm
Posted by jennifer at 04:07 PM | Comments (8) | TrackBack
January 31, 2007
Coral Reefs May Benefit From Global Warming
ON Friday in Paris the UN's Intergovernmental Panel on Climate Change will launch a new report, Climate Change 2007: The Physical Science Basis, with an up-to-date assessment of likely temperature rises because of global warming. Three related reports will be released later in the year, including a report on the likely effects of the rise in temperature. The report on impacts is likely to include a chapter on Australia and a warning that corals on the Great Barrier Reef could die as a consequence of global warming.
The idea that the Great Barrier Reef may be destroyed by global warming is not new, but it is a myth. The expected rise in sea level associated with global warming may benefit coral reefs and the Great Barrier Reef is likely to extend its range further south. Global threats to the coral reefs of the world include damaging fish practices and pollution, and the UN should work harder to address these issues.
Read the complete article here: http://www.theaustralian.news.com.au/story/0,20867,21144521-7583,00.html
Posted by jennifer at 08:33 AM | Comments (152) | TrackBack
June 11, 2006
Florida Corals Not At Risk of Global Warming: Gary Sharp
Dr Gary Sharp, Scientific Director of the Center for Climate/Ocean Resource Study in Monterey Bay, California, makes a few good points regarding global warming and coral bleaching with particular reference to the Florida Keys in a recent article published by Tech Central Station titled, 'Coral Bleaching: What (or Who) Dunnit?':
1. Cold winters, not global warming, wiped out large areas of cold-sensitive corals in the Florida Keys in the late 1970s and early 1980s.
2. Coral reefs currently exists along a 6-7 degree temperature gradient so all the corals aren't likely to die from a projected 2 degree celsius warming.
3. Sea surface temperatures are unlikely to increase by 2 degree celsius because the ocean responses to "excessive heating" through Deep Convection when the sea surface temperture exceeds about 27.5C.
Read the full article here:
http://www.tcsdaily.com/article.aspx?id=042606B .
Posted by jennifer at 12:21 PM | Comments (4) | TrackBack
April 12, 2006
Coral Bleaching & The Reef: Walter Starck
There is a widespread belief, cultivated at least in part by Prof Ove Hoegh-Guldberg that global warming has resulted in more coral bleaching.
Given the interest in the subject, I have copied the following comment from Dr Walter Starck, from yesterday's rather long and tedious thread:
"Bleaching events result from extended periods of calm weather during which mixing from wave action ceases and surface water becomes exceptionally warm. Such warming is especially marked in very shallow water such as on reef flats. At the same time the absence of waves also eliminates the wave driven currents that normally flush the reef top. Bleaching conditions require at least a week or more of calm weather to develop and this may happen every few years, only once in a century, or never, depending on geographic location. On the outer GBR it is uncommon due to ocean swell and currents even in calm weather. In the mid-shelf and inshore areas it is much more common due to the absence of swell and reduced currents.Characteristic bleaching scars and isotope temperature records from coral cores commonly show evidence of past bleaching events going back thousands of years. There is no evidence for a recent increase in frequency and/or severity of bleaching events and nothing to link extended periods of calm winds with global warming.
In past geologic periods when global climate was warmer than at present corals enjoyed greater latitudinal distribution. The most likely effect of a warming climate on reefs would seem to be an expansion of their geographic distribution and there is some evidence this is already happening. In Florida recent growth of coral has occurred farther north than it did a few decades ago and in the same areas sub-fossil corals indicate previous such advances in the recent geologic past.
Hoegh-Guldberg has found an attractive GW niche in the well established guild of GBR doomscryers. It has provided notoriety, acclaim and generous research support. Whether his prophesies will stand up to the reality test remains to be seen. Based on the track record of science based doomscrying his odds don't look too good. In fact sheep's entrails and tea leaves seem to produce better results, probably because they at least incorporate some element of intuitive judgment."
Last year Walter wrote a review titled 'Threats to the Great Barrier Reef', published by the IPA, it can be downloaded by clicking here.
This picture was taken at the Great Barrier Reef by Roger Steene:
Posted by jennifer at 01:25 PM | Comments (66) | TrackBack
April 11, 2006
Global Warming & The Reef: Andrew Bolt &
On 31st January there was a piece in The Age titled 'Scientists worried by reef bleaching' quoting Prof Ove Hoegh-Guldberg from the University of Queensland, with Don Henry from the Australian Conservation Foundation suggesting the problem of bleaching that Ove was so worried about, could be fixed if only the Australian government ratified the Kyoto Protocol.
I received an email from a reader of this blog a couple of weeks ago pointing out that expert, and academic, Prof Ove Hoegh-Guldberg keeps changing his tune on global warming and its impact on the reef. He wrote:
"Within a little over a month, Ove Hoegh-Guldberg's estimates have dropped from 50-60 percent to 1 percent of the reef bleached. That is simply an amazing change over a short period of time, particularly when you consider the amount of time required to do field work, analyse data etc. In the later article, Ove appears to be discrediting the scientists who made the initial estimates, when of course they were his! I will be interested to see if Ove makes a statement also modiyfing his claims that the reef will be dead and barren within 30 to 50 years. My feeling is that the initial claims were simply scaremongering and the disappointing thing is his willingness to go public with such claims with only preliminary data rather than any real published material."
Herald Sun Columnist Andrew Bolt also noticed the inconsistencies in the advice from Ove:
"How many times must the experts be wrong about Barrier Reef devastation before we disbelieve their scares?HOW many times must the Great Barrier Reef "survive" before we figure it's not really dying?
Actually, the real question is a bit ruder.
As in: How many times can global-warming alarmists such as Prof Ove Hoegh-Guldberg be wrong about the reef's "devastation" before we learn to ignore their scares?
The trouble is our reef is so well-loved that green militants, desperate that we back their theory of man-made global warming, consider it the perfect hostage.
No month goes by without one screaming: "Freeze! Out of the car, or the reef gets it!"
And Hoegh-Guldberg, head of Queensland University's Centre for Marine Studies, has threatened us more often than most.
Just three months ago he was at it again, issuing a press release with a grim warning: High temperatures meant "between 30 and 40 per cent of coral on Queensland's Great Barrier Reef could die within a month".
Just four paragraphs on he upped the ante, warning that the warm seas "may result in greater damage" still -- to more than 60 per cent of the reef -- and we "have to rapidly reduce the rate of global warming by reducing carbon dioxide emissions."
You heard him, jerk. Get out of your car.
But as anyone who's seen the reef lately knows, it's still there and still beautiful.
Ask -- hey! -- Hoegh-Guldberg himself. He's just back from a trip out to the outer reef and reports that, um, the bleaching, er, has had, well, "quite a minimal impact", after all. In fact, just 1 per cent was affected.
And history tells us even that little bit will recover.
What history? The history of an earlier Hoegh-Guldberg scare.
In 1999, Hoegh-Guldberg was commissioned by Greenpeace -- warning -- to find out why bits of the reef had just turned white.
Global warming was to blame, he concluded, which pleased Greenpeace awfully.
More, it moaned, and the professor obliged: Warming seas meant "coral reefs could be eliminated from most areas of the world by 2100".
Click here to keep reading.
You don't need to be really clever to work out that global warming might not be so good for polar bears, but it is probably going to be OK for Nemo, as I've explained previously, click here.
But even the Australian Financial Review can't help but scaremonger. An article in the Review on Friday (BCA Warms to Climate Change Rethink, pg. 57) claimed a 1C temperature rise would result in 81 percent of the Great Barrier Reef bleaching. One degree was the extent of the temperature rise last year according to the Bureau of Meterology. The Review would have published the one degree temperature rise for last year, and is now publishing that a one degree rise will bleach most of the reef! How confused must editors and journalists be with all the global warming scaremongering?
Several commentators at this blog have been indignant about the letter from the 60 skeptics in which the scientists suggested there has been some exaggeration, and there could be more public consultation about climate change issues (see comments following the blog post here). They claim the letter ignores the science and seriousness of the issue and is just about playing politics. But these same commentators will ignore the more ridiculous claims from Ove and other 'believers' who spin stories that result in completely nonsense predictions.
On a brighter note, here is a little Nemo from The Great Barrier Reef:
Posted by jennifer at 12:19 PM | Comments (136) | TrackBack
April 09, 2006
A Green Turtle @ Saxon Reef @ The Great Barrier Reef
I went snorkling on Saturday off Cairns. It was a magnificent day. I saw lots of fish and coral. But the highlight was swimming with this green turtle at Saxon reef.
You can't properly see the turtle's head for its fin, but poking out from its mouth is a bit of seaweed which it had snatched from my fingers.
Posted by jennifer at 08:13 PM | Comments (2) | TrackBack