Monday, June 15, 2015
Coral not co-operating with Warmist theory
As the ocean absorbs atmospheric carbon dioxide (CO2) released by the burning of fossil fuels, its chemistry is changing. The CO2 reacts with water molecules, lowering the ocean's pH in a process known as ocean acidification. This process also removes carbonate ions, an essential ingredient needed by corals and other organisms to build their skeletons and shells.
Will some corals be able to adapt to these rapidly changing conditions? If so, what will these coral reefs look like as the oceans become more acidic?
In addition to laboratory experiments that simulate future ocean conditions, scientists are studying coral reefs in areas of the ocean where low pH is naturally occurring to try and answer important questions about ocean acidification, which threatens coral reef ecosystems worldwide.
One such place is Palau, an archipelago in the far western Pacific Ocean. The tropical, turquoise waters of the Palau Rock Islands are naturally more acidic due to a combination of biological activity and the long residence time of seawater within its maze of lagoons and inlets. Seawater pH within the Rock Island lagoons is as low now as the open ocean is projected to be as a result of ocean acidification near the end of this century.
A new study led by scientists at Woods Hole Oceanographic Institution (WHOI) found that the coral reefs there seem to be defying the odds, showing none of the predicted responses to low pH except for an increase in bioerosion -- the physical breakdown of coral skeletons by boring organisms such as mollusks and worms. The paper is to be published June 5 in the journal Science Advances.
'Based on lab experiments and studies of other naturally low pH reef systems, this is the opposite of what we expected,' says lead author Hannah Barkley, a graduate student in the WHOI-MIT joint program in oceanography.
Experiments measuring corals' responses to a variety of low pH conditions have shown a range of negative impacts, such as fewer varieties of corals, more algae growth, lower rates of calcium carbonate production (growth), and juvenile corals that have difficulty constructing skeletons.
'Surprisingly, in Palau where the pH is lowest, we see a coral community that hosts more species, and has greater coral cover than in the sites where pH is normal,' says Anne Cohen, a co-author on the study and Barkley's advisor at WHOI. 'That's not to say the coral community is thriving because of it, rather it is thriving despite the low pH, and we need to understand how.'
Friday, June 5, 2015
Coral growth and thriving shows no clear connection to temperature variations
The paper below is not easy for a non-specialist to follow but my heading above sums up its major finding. Global warming won't bother it, in other words
Regional coral responses to climate disturbances and warming is predicted by multivariate stress model and not temperature threshold metrics
Timothy R. McClanahan, Joseph Maina, Mebrahtu Ateweberhan
Oceanic environmental variables derived from satellites are increasingly being used to predict ecosystem states and climate impacts. Despite the concerted efforts to develop metrics and the urgency to inform policy, management plans, and actions, few metrics have been empirically tested with field data for testing their predictive ability, refinement, and eventual implementation as predictive tools. In this study, the abilities of three variations of a thermal threshold index and a multivariate stress model (MSM) were used to predict coral cover and community susceptibility to bleaching based on a compilation of field data from Indian Ocean reefs across the strong thermal anomaly of 1998. Field data included the relative abundance of coral taxa 10 years before the large-scale temperature anomaly, 2 years after (1999–2000), and during the post-bleaching recovery period (2001–2005) were tested against 1) a multivariate model based on 11 environmental variables used to predict stress or environmental exposure (MSM), 2) estimates of the time until the current mean maximum temperature becomes the mean summer condition (TtT), 3) the Cumulative Thermal Stress (CTS) for the full satellite record, and 4) the 1998 Annual Thermal Stress (1998 ATS). The MSM showed significant fit with the post-1998 cover and susceptibility of the coral community taxa (r2 = 0.50 and 0.31, respectively). Temperature threshold indices were highly variable and had relatively weak or no significant relationships with coral cover and susceptibility. The ecosystem response of coral reefs to climatic and other disturbances is more complex than predicted by models based largely on temperature anomalies and thresholds only. This implies heterogeneous environmental causes and responses to climate disturbances and warming and predictive models should consider a more comprehensive multiple parameter approach.
Climatic Change, April 2015
Friday, May 15, 2015
Is Australia's Great Barrier Reef 'In Danger'?
If I have the time I do sometimes read Australia's far-Left "New Matilda". I would like to start a blog that regularly demolished their articles -- perhaps to be called "Walzing New Matilda" -- but I have weightier matters to spend my time on. Anyway, the article below is up to its usual standard of presenting only half of the story. Balance is the Devil incarnate to Leftists.
Some scientists do say that the GBR has shrunk by 50% but the interesting question is why there has been any shrinkage at all. The Warmist below knows why, of course. It's because of global warming. Pesky that there has been no global warming for 18 years though. Can something that does not exist cause anything? They also seem to think that Richard Branson is a climate scientist. Enough said on that.
The key point, however, is that the reef does get heavily impacted by natural events such as the many cyclones that have hit North Queensland in recent years. Cyclones are very destructive of coral. HOWEVER, when we look at that storm destruction, we also find that corals grow back rapidly. While that happens, the GBR is in no "danger". Any changes are temporary. See here and here, for instance.
Warmists will say that the cyclones were caused by global warming but again I ask: Can something that does not exist cause anything?
Billionaire Richard Branson has urged the United Nations to list the World Heritage value of the Great Barrier Reef as ‘in danger’ after being approached by advocacy group 1Million Women.
While admitting the campaign may seem “counter intuitive”, Branson argues it is an effective way to “stop further irreversible damage” to the reef “and to protect it for generations to come”.
“Saying the Great Barrier Reef is ‘in danger’ could be just what it needs,” Branson wrote in a blog post yesterday.
The United Nations World Heritage Committee is set to make a decision on whether to change the listing of the reef at a meeting in Bonn, Germany, in June this year.
Like Branson, the UN has expressed concern that port developments and coal ships set to service Australia’s largest ever coal mine, which the federal government approved last year, will further damage the reef.
The Great Barrier Reef has already lost half of its coral cover in the last three decades, and it faces further threats from the Crown of Thorns Starfish and increased agriculture run-off.
In 2013, a federal government report noted that 24 out of 41 attributes which make up the ‘Outstanding Universal Value’ of the reef under the World Heritage Convention are deteriorating.
But the greatest threat to the reef, according to government scientists, is climate change. “The reef’s plight, like many others, is unbearably sad,” Branson said. “It is being totally overwhelmed by climate change impacts through a destructive combination of heat-driven coral bleaching, ocean acidification and tropical storms.”
Despite climate change being the greatest threat to the reef, a recent Australian Government plan designed to guide conservation efforts for the next 35 years and address UN concerns made next to no mention of the risk to the reef from rising emissions.
On Thursday, the United Nations warned that for the first time in millions of years the concentration of carbon dioxide in the earths atmosphere exceeded 400 parts per million.
The Greens environment spokesperson, Larissa Waters, said on Wednesday that she doesn’t “think the government has done enough policy-wise to avert the threat of a world heritage in danger listing for the Great Barrier Reef”.
“Which is an absolute tragedy,” she said, “because we’re talking about one of the seven wonders of the world.”
“The foremost World Heritage Committee has for the past four years now said to Australia ‘slow down, you’re on this path of industrialisation, we’re worried about the future of the reef, your own scientists are worried about the future of your reef, what are you going to do about it?”
“And the government has consistently thumbed its nose at the key recommendations, and it’s made some changes around the edges.”
Waters said she hopes the reef is not listed as ‘in danger’, despite the fact it is “in serious jeopardy”.
Yesterday, The World Wildlife Fund has released a ‘to do’ list, lobbying the government to do more than is proposed in its ‘Reef 2050’ plan.
At least one federal MP is likely to be unimpressed with these recent developments.
George Christensen MP, whose electorate of Dawson takes in part of the Great Barrier Reef, is standing by the government’s “exemplary document”.
The outspoken backbencher recently voiced his outrage at “eco-traitors” who are committing the “treason” of advocating for an ‘in danger’ listing.
“These extreme greens act like Wormtongue from The Lord of the Rings, flying overseas and whispering in the ears of the decision-makers and diplomats who have anything to do with UNESCO and the World Heritage Committee, poisoning their minds on the state of the reef,” Christensen said.
“They belong to groups such as Greenpeace, the Australian Marine Conservation Society, Friends of the Earth, Get Up, and the Environmental Defenders Office.”
Thursday, May 14, 2015
Parental environment mediates impacts of increased carbon dioxide on a coral reef fish
Fish adapt rapidly to climate change -- within one generation
Gabrielle M. Miller et al.
Carbon dioxide concentrations in the surface ocean are increasing owing to rising CO2 concentrations in the atmosphere1. Higher CO2 levels are predicted to affect essential physiological processes of many aquatic organisms2, 3, leading to widespread impacts on marine diversity and ecosystem function, especially when combined with the effects of global warming4, 5, 6. Yet the ability for marine species to adjust to increasing CO2 levels over many generations is an unresolved issue. Here we show that ocean conditions projected for the end of the century (approximately 1,000 μatm CO2 and a temperature rise of 1.5–3.0 °C) cause an increase in metabolic rate and decreases in length, weight, condition and survival of juvenile fish. However, these effects are absent or reversed when parents also experience high CO2 concentrations. Our results show that non-genetic parental effects can dramatically alter the response of marine organisms to increasing CO2 and demonstrate that some species have more capacity to acclimate to ocean acidification than previously thought.
Nature Climate Change 2, 858–861 (2012) doi:10.1038/nclimate1599
Tuesday, April 14, 2015
Heat Resistance in Reef-Building Corals
Discussing: Bay, R.A. and Palumbi, S.R. 2014. "Multi-locus adaptation associated with heat resistance in reef-building corals". Current Biology 24: 252-2956.
Introducing their informative study, Bay and Palumbi (2014) write that "physiology and gene expression patterns have shown that corals living in naturally high-temperature microclimates are more resistant to bleaching because of both acclimation and fixed effects, including adaptation," citing in this regard the slightly earlier work of Palumbi et al. (2014). And in further searching for potential genetic correlates of these fixed effects, they go on to describe how they "genotyped 15,399 single nucleotide polymorphisms (SNPs) in 23 individual table top corals, Acropora hyacinthus, within a natural temperature mosaic in backreef lagoons on Ofu Island, American Samoa."
This effort led to the two researchers identifying 114 highly divergent SNPs that appeared to be good candidates for environmental selection, as a result of multiple stringent outlier tests they conducted, as well as the corals' evident correlations with temperature. More specifically, they report that "corals from the warmest reef location had higher minor allele frequencies across these candidate SNPs, a pattern not seen for non-candidate loci." In addition, they discovered that "within backreef pools, colonies in the warmest microclimates had a higher number and frequency of alternative alleles at candidate loci."
In discussing the significance of their findings, Bay and Palumbi say they imply a "mild selection for alternate alleles at many loci in these corals during high heat episodes and possible maintenance of extensive polymorphism through multi-locus balancing selection in a heterogeneous environment," which leads them to their ultimate conclusion that a natural population of these corals "harbors a reservoir of alleles preadapted to high temperatures, suggesting potential for future evolutionary response to climate change."
Tuesday, March 24, 2015
Australia: Dredges will not damage reef
Greenie scaremongering has no scientific basis
The resources and ports sectors continue to defend their dredging practices as safe after the Queensland and federal governments unveiled a long-term Great Barrier Reef management plan.
The plan includes a ban on dumping dredge spoil anywhere in the world heritage area, a limit on port expansion to four sites and targets for reducing sediment, nutrient and pesticide contamination.
It will be a key factor in the UNESCO world heritage committee's decision on whether to list the reef as "in danger" in June this year.
The Greens on Monday urged the federal government to go further after the Australian Coral Reef Society released a report recommending against the expansion of the Abbot Point coal terminal in central Queensland.
Top coral reef scientists were presenting a choice between protecting the Great Barrier Reef and developing Queensland's Galilee Basin, Greens senator Larissa Waters said. "In an age of climate change, it's scientifically impossible to do both," she said.
"The Abbott and Palaszczuk government's Reef 2050 Plan for the World Heritage Committee completely ignores the impact of the Galilee Basin coal mines on the reef and other world heritage areas."
Ms Waters said increased shipping through the reef would lead to ocean acidification, more dangerous storms and coral bleaching.
But linking the basin's development to the reef's plight was "a new low point in a campaign of misinformation", GVK Hancock said.
Every reputable analyst agreed that global demand for coal would grow for many decades regardless of the basin's development, spokesman Josh Euler said. "If we as a nation don't develop the Galilee Basin then some other country will develop their equivalent resource," he said.
Mr Euler said this would allow competitors to gain significant financial and employment benefits. "The expansion of the existing Abbot Point Port will not impact the Great Barrier Reef."
The government's plan ignores a science-based approach to dredging, according to Ports Australia.
An unwarranted blanket ban on dredging was placing the long-term viability of the ports system at risk, according to chief executive David Anderson.
"The science has been discarded, and instead the policy has been dictated by an activist ideology, with the complicity of UNESCO, which has swayed these governments," he said.
Wednesday, February 18, 2015
The totally unscientific ocean acidification fraud lives on
CO2 dissolved in water produces carbonic acid and the Warmists ride that for all they're worth. But warming seas would OUTGAS CO2. That's what warm water does with dissolved CO2. Open a warm bottle of Coke and see it happening for yourself. And less CO2 means there is less carbonic acid, so if warming happens we will have LESS acidic oceans.
If acidity levels are in fact rising, that proves that there is NO warming going on and probably some cooling. And the ocean is quite alkaline so what warmists call acidification is in fact just a small reduction in alkalinity.
So it is no wonder that the prophesied damage to the shells of marine creatures just is not happening. Marine creatures can in fact benefit from the "acidification". See also here on the harmlessness of more acid seas. And another report on the benefit of such seas.
All the studies mentioned above were observations of events in nature, whereas the harm observed in the study below was NOT found in the natural world but only in a tank with artificially high levels of acidity
It's a great theory that more acid seas will harm marine life but it is also a sophomoric oversimplification that has no regard for the complexity of the natural world. Warmism could be summarized as "Lies, damn lies and no statistics"
Satellite images are being used to monitor how ocean acidification is changing the world's seas.
For the first time, scientists have been able to obtain a global picture of how rising carbon dioxide levels in the atmosphere are affecting the oceans.
Using thermal cameras and microwave sensors mounted on satellites orbiting 435 miles above Earth, the experts said it's possible to assess which areas of the ocean are most at risk of acidification.
As the acidity of seawater rises, it can change the chemistry of the oceans and is expected to have a profound affect on marine animals.
A recent study funded by the European Union found that ocean acidification is already having a profound impact on herring in the Baltic Sea. This heavily fished area has already seen pH values of 7.2 being recorded, so scientists wanted to see what impact it was having.
They hatched eggs taken from herring caught off the coast of Norway and reared them in outdoor tanks with different levels of aciditiy.
Those reared in tanks with pH values of 7.45 and 7.07 showed more signs of organ damage than those in low acidity water. They had more damage in the liver, kidneys and their fins were often abnormally shaped while they tended to develop more slowly.
After 39 days, the fish larvae in the medium acidity tank weighed 30 per cent less than those in normal waters while those in the high acidity tank weighted 40 per cent less.
The researchers said that these smaller fish would be more at risk of being preyed upon and are less able to survive.
Shellfish will struggle to find enough of the minerals they use to make their shells while the fish that feed on them will also suffer.
It is estimated that around a quarter of the carbon dioxide emitted into the atmosphere is absorbed by the ocean.
Tuesday, January 27, 2015
Australian public broadcaster uses "Have you stopped beating your wife" question to imply that mining is allowed on the Barrier Reef
COMMUNICATIONS Minister Malcolm Turnbull says an ABC survey question about mining in waters near the Great Barrier Reef “does not appear to be accurate” but placed responsibility on the broadcaster’s board of directors.
The ABC was accused last week of “push polling” with a “mischievous” question in an online Queensland election survey, which asked voters how much mining activity they thought should be permitted in the waters around the reef.
The possible answers included “much more”, “somewhat more”, “about the same as now”, “somewhat less”, “much less” or “don’t know”.
The question was included in the broadcaster’s Vote Compass poll — an online venture with the University of Queensland and Canadian research firm Vox Pop Labs — which matches respondents’ policy leanings with the parties’ policies.
“The policy about mining on the Great Barrier Reef is quite clear and the way it was described or summarised in that question does not appear to be accurate to me,” Mr Turnbull said. “But the responsibility for ensuring the ABC news and information is accurate and impartial is up to the board of directors.”
The Whitlam government ruled the 344,400sq km Great Barrier Reef Marine Park off-limits to mining in 1975.
Mr Turnbull said he did not want to give a “running commentary” on the ABC but told The Australian: “Their act is very, very clear. “Under Section 8, the responsibility of ensuring that the ABC’s news and information is accurate and impartial lies with the board of directors.
“The ABC is a government broadcaster, it belongs to government, but we don’t control the editorial line.”
Last week, Liberal National Party senator Matt Canavan demanded the “mischievous” question be removed and accused the ABC of “push polling” by using the survey to influence votes. “That question-and-answer set indicates to any reasonable person that the Queensland government allows mining in the waters of the Great Barrier Reef,” he said. “It’s a bit like asking a question on public urination. Should you do it somewhat less, somewhat more, much less, much more? The question is absurd. “That behaviour is prohibited, the way mining in the GBR is prohibited.”
The ABC has declined to change the question, claiming “mining activity” includes more than actual mining.
Vox Pop Labs director Cliff van der Linden supported the ABC’s position, saying the LNP was sent the questions ahead of time to provide its answers and it was “implicit” the party could have challenged the wording of the questions.
In an opinion piece for the ABC’s The Drum, Mr van der Linden said the “fundamental shortcoming” with Senator Canavan’s argument was there was no acknowledgment of mining activity near the Great Barrier Reef that “extends well beyond drilling”.
“This includes but is not limited to shipping lanes through the reef for coal exports, demands by mines on the local water supply, and the recently scrapped proposal to dump dredge from coal port developments on the Great Barrier Reef,” he wrote.
“Asking Vote Compass users about how much mining activity should be permitted in the waters around the Great Barrier is thus a perfectly legitimate question.”
Tuesday, December 30, 2014
Greenie misconceptions about the Great Barrier Reef
VISITORS to north Queensland who come to see the reef and rainforest are often perplexed to gaze from their hotel balconies out on to a wind-ruffled, muddy grey to brown-coloured sea.
What happened to the sparkling blue waters, they ponder. Fuelled by dim memories of media misreports, they usually jump to the conclusion that human pollution must be the cause.
Those who live along the Queensland coast, as opposed to those who preach about it from the concrete and glass metropolitan jungle, know that muddy coastal water is an intrinsic part of the natural tropical system, generated by the resuspension of seabed mud by constantly blowing southeast trade winds.
Indeed, special types of coral reef — turbid-water reefs — have evolved to live happily in just these muddy near-shore waters. The Great Barrier Reef itself — growing luxuriantly in pellucid blue, oceanic waters far offshore — is recognised in textbooks as one part of a larger mixed carbonate-terrigenous complex of both muddy (inshore) and bluewater (offshore) reefs with a long, robust geological history.
Along the Queensland coast, the shoreline is made up of sandy beaches and adjacent sandy-mud coastal lagoons and estuaries, punctuated by spaced rocky headlands. The nearby inner shelf seabed is almost flat and covered by a blanket of sandy mud and mud up to several metres thick that has accumulated during the past few thousand years.
This coastal-inner shelf system has been built, and is still nurtured, by sand and mud delivered to the coast from the Queensland hinterland at times of riverine flood — mostly after cyclones.
Dilute muddy water from even the greatest cyclonic floods only reaches from the coast to the offshore bluewater reefs about once every 10 years. It persists there just briefly before being dispersed by waves and currents, and in being dispersed introduces rare nutrients into a nutrient-starved locale.
The coastal wetlands are important ecosystems for mangrove growth and provide a nurturing environment for fish and invertebrate larvae. Also, shallow embayments with sandy low tide and subtidal beach flats provide the conditions for seagrass growth — an essential habitat for dugongs.
Prior to European settlement, this system existed in precarious but dynamic “balance”, with major cyclones causing immediate coastline erosion, followed months to years later by fairweather shoreline accretion and restoration, fed by sediment contributed by the same and earlier cyclones. It is possible that historical tree-clearing and grazing inland has increased the amount of sand and mud delivered to the coast in post-European time, with one computer model estimate of a two to four -fold increase.
If true, such sediment enhancement is no bad thing. First, the pre-European shoreline was, and remains, deficient of enough sediment to maintain its position without continuing sand nourishment, especially at locations away from river mouths. Second, more sediment nurtures not just the shoreline beaches but feeds nutrient into the ecologically vital coastal wetlands.
Ports and their access channels have been dredged along the Queensland coast since the late 19th century, and the spoil dumped at sea. Over a period of months to years, this spoil is redistributed across a wide area and merges insensibly into the sandy mud, inner shelf substrate.
The briefly enhanced turbidity caused by dredging and dumping activity represents but a small, localised disturbance within a dynamic oceanographic background that sees constantly varying rates of mud resuspension caused by wind, and by the regular interchange of shelf waters within a few days to weeks by tidal and other marine currents.
Not surprisingly, therefore, despite expensive nutrient and water quality analysis in the past 30 years, no measured evidence exists for changes in water quality on the near-shore GBR shelf in post-European time.
Furthermore, the historical dredging and spoil dumping on the shelf has had no other known significantly adverse effects either, especially not on the bluewater reefs in the distant offshore.
Spoil has sometimes been dumped at the shoreline to reclaim areas for port development — the Brisbane and Townsville ports are prime examples. Given the value of the land created, this is an entirely sensible procedure when undertaken (as it has been) as an environmentally efficacious and cost-effective commercial venture.
It is simply fallacious for conservationists to trumpet that the GBR is threatened by near-shore dredging, and it is risible and disgraceful that an international agency (UNESCO) is involved in unscientific grandstanding on the matter as well.
Caving in to activists, the federal government has rejected the two best environmental options for the spoil — either seabed dispersal or land reclamation. Instead, Environment Minister Greg Hunt has opted for the worst and possibly the most expensive environmental option — that spoil dredged from near Abbot Point will be dumped on land.
A more perfect combination of scientific ignorance and environmental stupidity would be hard to find.
Sunday, November 23, 2014
Good news: Leftist newspaper says the Australian government's climate change credentials have been battered
And see below that it includes some surprising claims, such as: "The size of the Reef has halved in the past 30 years". I have been following the barrier reef scares for around 60 years (long before global warming was invented) but that was a newie on me.
But I have traced the claim, and one amusing thing that we read there is: "The exhaustive AIMS investigation reveals coral loss is uneven along the 2300km-long reef, with the far north still relatively healthy." So the WARMEST parts of the reef are doing best! How pesky can you get?
And what the research showed is NOT that the reef has shrunk by 50% but that the CORAL has shrunk by 50%. The reef is of course an ancient and relatively permanent structure of dead coral skeletons.
We also read: "Storm damage accounted for 48 per cent of the coral loss in the past 27 years, crown-of-thorns starfish were responsible for 42 per cent, and bleaching caused 10 per cent of the coral to die". No mention of global warming! Though no doubt they would claim that the storms were caused by global warming. Since severe weather events worldwide have been FEWER in recent years that however would be a rubbish claim, having no regard to the actual statistics.
Warmists have also been known to link starfish plagues with warming but again we read: "The study says the causes of the plagues were still not fully known".
And I won't mention that the period covered by the research was 27 years, not 30.
And I won't mention that the source paper for the research is no longer where it was. Has it been taken down due to inaccuracy?
I could go on but the lesson is clear: As soon as we get into the details of the research findings, the sweeping claims made of the research by Warmists are extensively falsified. So the appeals to authority below are junk. It is the facts that matter, not authorities, and the facts are very pesky indeed for Warmists.
My habit of going back to the detailed research findings behind Green/Left claims once again shows what crooks and crazies they are
Prime Minister Tony Abbott's apparent, if modest, conversion to the idea that climate change was an "important subject" following talks with French president Francois Hollande on Wednesday was greeted with no small measure of cynicism.
This was, after all, a politician who had built a political career on climate scepticism, with his famous remark in 2010 that it was "absolute crap" to assert the science was settled.
It took only two days, but the doubters can claim vindication after revelations that the government sent a briefing note to Barack Obama to dissuade him that the Great Barrier Reef was under threat by climate change.
In an interview with Fairfax Media's Latika Bourke in New York, Minister for Foreign Affairs Julie Bishop said the Reef was "not under threat from climate change because its biggest threat is the nutrient runoffs agricultural land, the second biggest threat is natural disasters, but this has been for 200 years".
This is disingenuous, and factually wrong.
To be sure, the government believes the world is warming, and that human factors play a part.
But when it comes to acknowledging the urgency of the problem, how climate change will impact on the world, and what must be done to avert a catastrophic four-degree rise in global temperature, the Abbott government offers obfuscation and excuses.
So it was with the response to Obama's speech in Brisbane last week, when the US leader called on Australia's youth to rise up and demand more action to combat climate change, remarking that "incredible natural glory of the Great Barrier Reef is threatened".
The US leader's speech might have been undiplomatic and rude to his hosts - but his analysis of the impact of climate change on the Reef was spot on.
Just ask the federal government agencies charged with monitoring and protecting the Reef.
The Great Barrier Reef Marine Park Authority said in its 2014: "Climate change remains the most serious threat to the Great Barrier Reef. It is already affecting the reef and is likely to have far-reaching consequences in the decades to come."
Averting further degradation of the Reef can "only be successful if climatic conditions are stabilised" reported the Australian Institute of Marine Science (AIMS), another government body.
The size of the Reef has halved in the past 30 years. Outbreaks of crown of thorn starfish which consume soft corals - along with cyclones - have contributed to about 90 per cent of that decline, says AIMS.
Coral bleaching is responsible for the remaining 10 per cent.
Coral bleaching is the direct result of rising sea temperatures caused by global warming. The acceleration of crown of thorn starfish infestations - which spawn in warmer months - is also driven, at least in part, by hotter weather.
And, warns the government's marine scientists, cyclone activity will only increase as the planet heats up.
Bishop's personal political stocks have soared in recent months due to some forceful international diplomacy on the MH17 disaster and the rise of the Islamic State terrorist group.
Her intervention on the Reef is unlikely to faze Obama, or harm relations. But some of the gloss has come of Bishop's credentials as a moderate alternative to Abbott.
And, the government's climate change credentials, once again, have been battered.