Ozone hole over Antarctica expands to near-record levels, now four times size of Australia, ABC News The World Today , 3 Nov 15 By Lucy Carter The hole in the ozone layer over Antarctica has expanded to near-record levels this year, covering an area almost four times the size of Australia.
Scientists from the UN said the increase was due to colder-than-usual temperatures, rather than any extra damage being done to the Earth’s protective layer.
But that could still mean extra UV radiation and the risk of more people getting sunburnt in Australia’s southern states this summer.
The hole in the ozone layer above Antarctica has been carefully monitored for over 30 years.
According to atmospheric scientist Professor David Karoly from the University of Melbourne, its size fluctuates greatly when it emerges each spring. “Each springtime over the last now nearly 35 years, there’s been a depletion of stratospheric ozone over Antarctica primarily due to two really important factors,” he said.
“It’s the increase in ozone-depleting chemicals in the atmosphere and a very special cold conditions that occur in winter and spring over Antarctica which provide a special, if you like, catalytic ozone destruction vessel that allows the ozone to be rapidly deployed by the higher concentrations of chlorofluorocarbons — ozone-depleting chemicals that have occurred in the stratosphere due to human activity.”
The UN’s weather and climate agency said this year’s seasonal ozone hole peaked on October 2, covering an area over Antarctica of 28.2 million square kilometres — close to four times the size of Australia or the size of Russia and Canada combined…….
“We do know that the substances that cause the ozone hole, the chlorines and bromines up there are decreasing … have decreased by about 18 per cent since their peak in the late 1990s, early 2000s,” he said.
Since 1987, gases known to cause ozone depletion have been banned and last year the World Meteorological Organisation reported the first positive signs of “ozone recovery”.
Professor David Karoly from the University of Melbourne said this fluctuation in size was not a long-term concern.
“It makes it harder to then see the long-term improvement, the declining trend in the size of the ozone hole but that is still expected to continue,” he said.
“We expect in the southern hemisphere that the ozone hole will not completely recover for another 40 to 60 years, when it recovers back to pre-1980 levels when the ozone hole was first discovered.”
However, this year’s ozone hole size does have the potential to affect Australians.
“Once the ozone hole does start to break up, air that’s depleted in ozone may be transported over to the southern parts of Australia which can, of course, during those periods increase the amount of UV radiation which in the Earth’s surface,” Mr Krummel said.
“So there could be a tendency for a bit more sunburn. “I would say mostly the southern states is where it is likely to impact……..http://www.abc.net.au/news/2015-10-30/ozone-hole-over-antarctica-expands-to-near-record-levels/6898824
the results leave a narrow opening through which humanity can slip. If temperatures remain within 2C (3.6F), the collapse of the shelves will stabilise and the sheets will remain mostly intact. Sea-level rise from Antarctica would remain within 23cm (9 inches) by 2300.
To achieve this, the authors said the world will have to follow the Intergovernmental Panel on Climate Change’s (IPCC) lowest emissions scenario.This requires global emissions to peak around 2020 and decline to below zero by 2100.
The new study “ultimately confirm[s] the suspicions of earlier glaciologists that the fate of ice shelves largely determines whether Antarctica contributes less than 1 metre or up to 9 metres to long-term sea-level rise”
Antarctic ice sheets face catastrophic collapse without deep emissionscuts, http://www.theguardian.com/environment/2015/oct/14/antarctic-ice-sheets-face-catastrophic-collapse-without-deep-emissions-cuts Guardian, Karl Mathiesen, 15 Oct 15
Study finds that a global temperature increase of 3C would cause ice shelves to disappear, triggering sea-level rise that would continue for thousands of years. A team of researchers has found that steep cuts to emissions during the next decade are the only way to avoid a catastrophic collapse of Antarctic ice sheets and associated sea-level rise that will continue for thousands of years.
The study, published in the journal Nature on Wednesday, found that should the global temperature increase to around 3C (5.4F) above the pre-industrial era then the ice shelves that hold back the giant continental ice sheets would be lost over the next few centuries. Continue reading
New study projects that melting of Antarctic ice shelves will intensify http://www.eurekalert.org/pub_releases/2015-10/whoi-nsp100915.phpWOODS HOLE OCEANOGRAPHIC INSTITUTION New research published today projects a doubling of surface melting of Antarctic ice shelves by 2050 and that by 2100 melting may surpass intensities associated with ice shelf collapse, if greenhouse gas emissions from fossil fuel consumption continue at the present rate.
Ice shelves are the floating extensions of the continent’s massive land-based ice sheets. While the melting or breakup of floating ice shelves does not directly raise sea level, ice shelves do have a “door stop” effect: They slow the flow of ice from glaciers and ice sheets into the ocean, where it melts and raises sea levels.
“Our results illustrate just how rapidly melting in Antarctica can intensify in a warming climate,” said Luke Trusel, lead author and postdoctoral scholar at Woods Hole Oceanographic Institution (WHOI). “This has already occurred in places like the Antarctic Peninsula where we’ve observed warming and abrupt ice shelf collapses in the last few decades. Our model projections show that similar levels of melt may occur across coastal Antarctica near the end of this century, raising concerns about future ice shelf stability.”
The study, published Oct. 12, 2015, in Nature Geoscience, was conducted by Trusel, Clark University Associate Professor of Geography Karen Frey, WHOI scientists Sarah Das and Kristopher Karnauskas, Peter Kuipers Munneke and Michiel R. van den Broeke of the Institute for Marine and Atmospheric Research Utrecht University, and Erik van Meijgaard of the Royal Netherlands Meteorological Institute.
To study how melting evolves over time and to predict future ice sheet melting along the entire Antarctic coastline, the scientists combined satellite observations of ice surface melting with climate model simulations under scenarios of intermediate and high levels of greenhouse gas emissions until the year 2100.
The results indicate a strong potential for the doubling of Antarctica-wide ice sheet surface melting by 2050, under either emissions scenario. However, between 2050 and 2100, the models reveal a significant divergence between the two scenarios. Under the high-emissions climate scenario, by 2100 ice sheet surface melting approaches or exceeds intensities associated with ice shelf collapse in the past. Under the reduced-emissions scenario, there is relatively little increase in ice sheet melting after the doubling in 2050.
“The data presented in this study clearly show that climate policy, and therefore the trajectory of greenhouse gas emissions over the coming century, have an enormous control over the future fate of surface melting of Antarctic ice shelves, which we must consider when assessing their long-term stability and potential indirect contributions to sea level rise,” said Frey.
Funding for the research was provided by NASA, the Doherty Postdoctoral Scholarship Program at WHOI, the Netherlands Earth System Science Centre, the Polar Program of the Netherlands Organization of Scientific Research, and the Dutch Ministry of Infrastructure and the Environment.
The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean’s role in the changing global environment. For more information, please visitwww.whoi.edu.
Why scientists are so worried about the ice shelves of Antarctica, WP, By Chelsea Harvey October 12 When it comes to climate change, Antarctica is one of the world’s major places of concern, mostly because of the sheer amount of ice it contains — enough to theoretically cause about 200 feet of sea-level rise if it were all to melt — not that anyone thinks that will happen anytime soon. Still, smaller parts could be destabilized, and understanding how the Antarctic ice sheet will react to future climate change is a big priority for scientists.
One important key to building this understanding is studying Antarctic ice shelves, which are large, floating platforms of ice — sometimes spanning hundreds or thousands of square miles — that form where where an ice sheet meets the ocean.
“They play an incredibly important role in constraining the flow of this land ice into the ocean,” says Luke Trusel, a postdoctoral scholar at the Woods Hole Oceanographic Institution, comparing ice shelves to the “cork in a champagne bottle.” If an ice shelf breaks off, it can unleash a flow of ice into the ocean from the ice sheet behind it, which can contribute to sea-level rise in a major way. Indeed, without ice shelves to provide buttressing, glaciers behind the ice shelves flow faster, pouring more and more ice into the ocean.
In order to get a better grip on how climate change could affect Antarctic ice shelves, Trusel and a group of other researchers conducted a study to see how rising air temperatures might affect surface melting in Antarctica. This is a process that can directly influence the destabilizing of ice shelves.
Past observations have shown that as ice melts on a shelf’s surface, the melted water starts to pool, or “pond,” and trickle down into imperfections in the ice, causing the cracks to deepen and widen — which can eventually cause ice shelves to collapse, unleashing the flow of land ice behind them.
“Increases in air temperature, and surface melt and ponding, has led to the abrupt and catastrophic collapse of a number of ice shelves,” says Trusel, lead author of the study, which was published Monday in Nature Geoscience. These collapses have mostly been observed on the Antarctic Peninsula, where the thinning and retreat of ice shelves has been particularly pronounced, thanks to higher-than-average warming in the area. The concern, though, is that more ice shelves that ring around Antarctica, including its colder regions, will start to give way as temperatures continue to rise and that other more inland parts of Antarctica will then follow suit.
The researchers used models to investigate the potential future impacts of two different climate scenarios: a “business-as-usual” trajectory, in which greenhouse gas emissions continue to rise throughout the century, and a more middle-of-the-road trajectory, in which emissions start declining before mid-century and there’s less associated global warming.
They found that under both scenarios, Antarctic-wide surface melt doubles by the year 2050, with the amount of meltwater produced coming close to 200 gigatons per year (a gigaton is a billion metric tons). This is a troubling finding, said Nerilie Abram, a researcher from the Centre of Excellence for Climate System Science at Australian National University who was not involved with the study, in an e-mail to The Post. But, she said, “I think that the more interesting result is to look at the huge divergence in predicted Antarctic ice melt during the second half of the century.”
After 2050, the projections for the two climate scenarios differ drastically. In the middle-of-the-road scenario, melt doesn’t increase much after mid-century. But in the business-as-usual scenario, melt continues to speed up, eventually hitting a rate of more than 600 gigatons per year by the end of the century.
“The most important results are … that we can see how quickly melting can evolve,” Trusel said. The results suggest that ice shelf surface melting increases exponentially with air temperature……….
One of the most important takeaways from the paper is “how important human action is on the climate of Antarctica,” Trusel added in a follow-up e-mail to The Post. Past observations show that humans have already altered the face of the continent, and the projections suggest that we have the power to continue doing so, he said.
“This shows that we do have a choice in how the Earth changes over the coming century,” said Abram, the researcher from Australian National University. “[We have] the option of a future where many of Antarctica’s ice shelves are still viable if we can curb emissions, compared to a future where many of Antarctica’s remaining ice shelves will probably have been lost if we continue our current emissions trajectory.” http://www.washingtonpost.com/news/energy-environment/wp/2015/10/12/why-scientists-are-worried-about-the-ice-shelves-of-antarctica/
This is quite an old article, but I find it remarkable because, for once, it mentions the enormous cost of security measures needed for small nuclear reactors in remote areas.
That is what is being proposed for Australia – by both the thorium enthusiasts, and the overseas companies desperate to keep the nuclear industry alive by selling small reactors to Australa (or, even more insidiously, by providing them to Australia “for free”, in exchange for South Australia importing radioactive trash, as outlined by nuclear proponent Oscar Archer )
the PM-2A’s purpose was to test whether reactors could be built in remote locations using prefabricated parts.
After the reactor was closed down, the US shipped 7700 cubic metres of radioactive contaminated rock and dirt to California, but passed through Dunedin, with a population of 124,000, the second largest city on New Zealand’s South Island, where it stayed for four days, raising local concerns, the New Zealand news site stuff.co.nz.
Russia has found that the logistics of even finding customers for its ANPP’s outweigh even the logistics of operating the plants. Russia has staked a financial bonanza on prospective orders for the plants, but there are, simply, no takers. And if there were, the logistics of securing such a plant against terrorists or accidents in remote areas would require at least the staff of a stationary plant.
Small-scale US nuclear reactor blamed for spiking cancer rates, casting pall over Russia’s FNPP fetish AMSTERDAM – A small nuclear power plant operated the United States at Antarctica’s McMurdo Sound has been implicated in dozens of cases of an unusual cancer in personnel who worked at or near the station between the years 1964 and 1973, US and New Zealand media have indicated. March 7, 2011 by Bellona Continue reading
Some Antarctic glaciers reached a tipping point in 2009 SARA PHILLIPS ABC Environmen t22 MAY 2015
Antarctic glaciers on the Bellinghausen Sea coast suddenly started melting in 2009.Credit: Alba Martin Espanol (Science)
Antarctic glaciers emptying into the Bellinghausen Sea all suddenly started melting around 2009. Scientists warn the sea level rise could be dramatic.
THE FIRST SIGNS Antarctic glaciers have reached some kind of melting ‘tipping point’ have been noticed by scientists from Europe.
The group of eight scientists, led by Dr Bert Wouters from the University of Bristol used sophisticated satellite measurements of the Antarctic glaciers that empty into the Bellinghausen Sea, on the Southern Antarctic Peninsula which reaches up almost to South America.
Glaciers are in effect, frozen rivers of snowpack, moving incrementally towards the ocean. These glaciers have existed in their current form for at least 5,000 years.
The scientists found that the height of the glaciers had dropped — some by as much as four metres. By analysing years of data, they could rule out the snow becoming more compact or a reduction in snowfall as the cause. This left only one possibility: that the glaciers were sliding faster towards the sea.
“The most likely explanation is that the glaciers have accelerated because the temperature of the ocean water has increased in the area, which we know from measurements. These warm waters will melt the floating ice shelves and the glaciers where they enter the sea from below and cause them to lose more ice,” said Dr Wouters, Marie Curie Research Fellow at the University of Bristol.
As the sea ice holding back the glaciers melts away, the glaciers slide faster into the sea. Last week researchers warned that elsewhere in Antarctica, the Larsen C ice shelf could collapse this century and what remains of the Larsen B ice shelf would be all gone by 2020, the majority of it having collapsed in 2002.
A tipping point
Curiously, the glaciers studied were relatively stable until 2009. After then, Dr Wouters said the glaciers appeared to have reached a “tipping point” with the glaciers studied simultaneously starting to slip into the sea…….http://www.abc.net.au/environment/articles/2015/05/22/4239285.htm
‘Stable’ Antarctic ice sheet may have started collapsing, scientists say, Guardian, Karl Mathiesen, 22 May 15 Southern Antarctic Peninsula ice sheet losing ice 8,500 times the mass of the Great Pyramid of Giza every year, satellite data shows A vast slab of Antarctic ice that was previously stable may have started to collapse, according to new analysis of satellite data.
Research published in the journal Science on Thursday found the Southern Antarctic Peninsula (SAP) ice sheet is losing ice into the ocean at a rate of 56 gigatons each year – about 8,500 times the mass of the Great Pyramid of Giza. This adds around 0.16mm per year to the global sea level.
The sheet’s thickness has remained stable since satellite observations began in 1992. But Professor Jonathan Bamber of Bristol university, who co-authored the study, said that around 2009 it very suddenly began to thin by an average of 42cm each year. Some areas had fallen by up to 4m.
“It hasn’t been going up, it hasn’t been going down – until 2009. Then it just seemed to pass some kind of critical threshold and went over a cliff and it’s been losing mass at a pretty much constant, rather large, rate,” said Bamber……http://www.theguardian.com/environment/2015/may/21/stable-antarctic-ice-sheet-may-have-started-collapsing-scientists-say
Unsustainable: the ugly truth about Rio Tinto‘, also reveals that Rio Tinto’s sustainability reporting contrasts sharply with the company’s actual performance in all four categories. It shows how Rio Tinto’s reckless pursuit of profit at any cost has caused disputes with numerous unions as well as environmental, indigenous and community groups. Most of the disputes covered in the report are ongoing. Rio Tinto has continued to provoke disputes in the three months since the report was released:
- with South African regulators by illegally operating a coal mine for a decade;
- with injured Australian workers by systematically targeting them in a layoff;
- with leaders in Zimbabwe by reportedly reneging on a pledge to support community development programs;
- and with the people of Papua New Guinea by rejecting calls for an investigation into the company’s role in a bloody civil war.
Rio Tinto will go on provoking disputes and operating in an unsustainable manner unless it believes that doing so could threaten its license to operate. To reform Rio Tinto, first we must threaten its ‘license to operate’
Rio Tinto’s ‘Sustainable Mining’ Claims Exposed By Kemal Özkan http://www.globalresearch.ca/rio-tintos-sustainable-mining-claims-exposed/5394301 July 31, 2014 Global mining giant Rio Tinto markets itself as a ‘sustainable company’. But serious failures in its reporting, and its attempt to hold an Australian indigenous group to ransom, reveal a very different truth: the company is driven by a reckless pursuit of profit at any cost. Rio Tinto uses its sustainability reporting to bolster the argument that it is a responsible company and therefore entitled to a license to operate. Now, a global campaign is demanding that Rio Tinto live up to its sustainability claims.
Rio Tinto subsidiary, Energy Resources of Australia (ERA), has threatened the Mirarr people that if it is not allowed to expand its Ranger uranium mining operations underground, it may be unable to fully fund rehabilitation of the open pit mine. The Ranger mine is located in the traditional lands of the Mirarr, the world heritage-listed Kakadu national park in Australia’s Northern Territory. If ERA does not complete rehabilitation of the site, which suffered a radioactive spill last year, the water, air quality and soil in the area could be scarred with toxic radiation for generations. Continue reading
Federal hearings exploring radiation exposure among McMurdo Navy veterans get underway in Washington http://www.newsnet5.com/dpp/news/local_news/investigations/federal-hearings-exploring-radiation-exposure-among-mcmurdo-navy-veterans-get-underway-in-washington Prompted by exclusive 5 On Your Side investigation Ron Regan, newsnet5.com WASHINGTON – Federal hearings prompted by an exclusive 5 On Your Side investigation into radiation exposure among McMurdo Navy veterans are scheduled to begin Tuesday morning.
Our investigative series revealed how a nuclear reactor at McMurdo Naval base in Antarctica continued to leak radiation for years and a possible link to cancer.
Our report documented 432 malfunctions at the plant from 1964 through 1972 while thousands of Navy veterans were stationed there.
Complaints from veterans dying from cancer were ignored by the Veterans Administration until our report exposed the radiation leaking that Navy veterans said was kept secret for decades.
Veterans have hope the hearings will provide them with assistance in compensation for their medical bills.
On Tuesday, the Veterans Advisory Board on Dose Reconstruction will discuss its final report and finding regarding the leaking nuclear reactor and veterans cancer.
Critics on all sides as Australia leads way on Antarctic protection BY: MATTHEW DENHOLM, TASMANIA CORRESPONDENT The Australian October 18, 2012 AUSTRALIA and France have developed a plan to protect 1.9 million square kilometres of east Antarctica as new marine parks, although a report today will call for an even larger reserve.
The Australia-France proposal, backed by the EU, covers seven coastal zones in east Antarctica…. (subscribers only)
Bomb spike hints on climate change AUSTRALIAN ANTARCTIC DIVISION 29 Nov 11 The discovery, reported in Global Change Biology, comes after researchers from the University of Wollongong (UOW) and the Australian Nuclear Science and TechnologyOrganisation (ANSTO) found that the dramatic increase in atmospheric radiocarbon (14C), known as the ‘bomb spike’, was detectable in living moss shoots 50 years after nuclear testing, and could be used to track changes in moss growth rates……Bomb spike hints on climate change. AUSTRALIAN ANTARCTIC DIVISION, 29 NOVEMBER 2011 Chemical clues absorbed from the atmosphere by Antarctic mosses during nuclear tests in the 1950s and 60s, have provided scientists with evidence of significant climate change in East Antarctica.
‘Our results point to a profound influence of recent climate change on the Antarctic flora, with δ13C profiles indicating the observed effects of temperature and wind speed are most likely due to the impact of these climate variables on water availability,’ Professor Robinson says. http://www.sciencealert.com.au/news/20112811-22889.html
Other McMurdo veterans across the US have now been revealed to have cancer………The first thing the doctors asked me was, well, that’s the type of cancer you typically get from exposure from radiation,” Boyles said.
Health fears around polar nuke leak | Stuff.co.nz, by Michael Field, 7 Mar 11, A small nuclear power plant used at McMurdo Sound near New Zealand’s Antarctic Scott Base is being implicated by US media in unusual cancers in men who worked on it in the 1960s.It has also been revealed the PM-3A nuclear power plant – known at MacTown as “nukey poo” for the way it leaked – had 438 malfunctions in its life between 1964 and 1973. Continue reading
Mawson Station has two turbines that provide more than 70 percent of its power needs. It should be noted, as the NREL explained, that often the combination of these two technologies is important. “Like many places, generating large amounts of renewable power in Antarctica with a single technology is unlikely. Fortunately, polar winds blow during the winter months when the sun does not shine.”
Clean Energy A Big Deal In Antarctica | EarthTechling by Nino Marchetti, July 19th, 2010“……….There seems to actually be quite a bit of renewable energy usage going on in Antarctica, according to the NREL. Continue reading
Australian uranium dust found in Antarctic ice ABC News (Australian Broadcasting Corporation) 3 May, 2010, An ice core from the Antarctic bears traces of uranium that may have been carried by the wind from Australian mines in 1995, a glacier expert has told a Chilean newspaper.The minuscule amounts of the radioactive element “correspond to a year (1995) when Australia increased its uranium production,” Ricardo Jana, who participates in an international research effort in the frozen continent, told El Mercurio daily.He said scientists theorise the uranium particles were carried by the wind from Australia and deposited in the northern part of the Antarctic’s Detroit peninsula. Australian uranium dust found in Antarctic ice – ABC News (Australian Broadcasting Corporati
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