Showing posts with label Environment. Show all posts
Showing posts with label Environment. Show all posts

Thursday, November 22, 2012

South Pacific Sandy Island 'proven not to exist'


South Pacific Sandy Island 'proven not to exist'

Sandy Island map Cartographers everywhere are now rushing to undiscover Sandy Island for ever

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A South Pacific island, shown on marine charts and world maps as well as on Google Earth and Google Maps, does not exist, Australian scientists say.
The supposedly sizeable strip of land, named Sandy Island on Google maps, was positioned midway between Australia and French-governed New Caledonia.
But when scientists from the University of Sydney went to the area, they found only the blue ocean of the Coral Sea.
The phantom island has featured in publications for at least a decade.
Scientist Maria Seton, who was on the ship, said that the team was expecting land, not 1,400m (4,620ft) of deep ocean.
"We wanted to check it out because the navigation charts on board the ship showed a water depth of 1,400m in that area - very deep," Dr Seton, from the University of Sydney, told the AFP news agency after the 25-day voyage.
"It's on Google Earth and other maps so we went to check and there was no island. We're really puzzled. It's quite bizarre.
"How did it find its way onto the maps? We just don't know, but we plan to follow up and find out."
Australian newspapers have reported that the invisible island would sit within French territorial waters if it existed - but does not feature on French government maps.
Australia's Hydrographic Service, which produces the country's nautical charts, says its appearance on some scientific maps and Google Earth could just be the result of human error, repeated down the years.
A spokesman from the service told Australian newspapers that while some map makers intentionally include phantom streets to prevent copyright infringements, that was was not usually the case with nautical charts because it would reduce confidence in them.
A spokesman for Google said they consult a variety of authoritative sources when making their maps.
"The world is a constantly changing place, the Google spokesman told AFP, "and keeping on top of these changes is a never-ending endeavour'.'
The BBC's Duncan Kennedy in Sydney says that while most explorers dream of discovering uncharted territory, the Australian team appears to have done the opposite - and cartographers everywhere are now rushing to undiscover Sandy Island for ever.

Source 

Thursday, March 8, 2012

Touch-and-go tablet and computer screens

Touch-and-go tablet and computer screens

(Copyright: Getty Images)

(Copyright: Getty Images)

The new iPad launched yesterday amid its usual fanfare. But could dwindling supplies of a crucial component make such events a thing of the past?

Another iPad launch, another event filled with intense anticipation and speculation. This time Apple’s CEO Tim Cook revealed that the latest iteration of iPad will feature a high-definition screen, and no doubt its competitors will rapidly follow suit.

But there is a problem looming on the horizon for fans of the latest tablet computers, not to mention smart phones and flatscreen TVs. Whether it is on the shiny new iPad, computer or phone, the chances are that you are reading this article through a screen laced with one of the rarest metals on Earth: indium. And analysts are warning that global supplies of indium could be exhausted as soon as 2017. So how will we live without the gadgets that we have come to depend on?

Such a prospect might not seem as alarming as running out of essential commodities, such as food or water. But over the past few decades digital displays have become so enmeshed in our lives that they are integral to our social interactions and livelihoods from rural East Africa to the offices of Wall Street. I have met Kenyan fisherwomen trading their wares via SMS to clients based hundreds of kilometres away – an opportunity that depends on indium just as much as my need to read these words I am typing on my computer monitor.

Wonder metal

Though it was discovered 150 years ago, indium’s remarkable qualities have been harnessed only recently to create wafer-thin electrodes. It is a very soft silvery metal that can be painted onto glass because unlike other soft metals, such as mercury, it wets the glass rather than forming beads. (Another curious property of indium is that when you bend a rod of the metal, it issues a high-pitched crackling sound, known as its “cry”.)

Indium is most useful, however, when it is manufactured into indium tin oxide, or ITO. The reason you cannot see it is because when indium reacts with oxygen, it becomes transparent. This, plus its tremendous ability to conduct electricity, allows our mobile phones to be smarter, our TV flatscreens to be larger and our tablet computers to be more sleek.

As a result, the price of indium has rocketed in recent years – it went from $60 per kilogramme in 2003 to $1,000 in just three years – giving rise to a whole new indium smuggling industry, primarily out of China. And there is no let up on our demand for hi-tech displays – there were more than 1.5 billion mobile phone handsets alone sold in 2011, one of which was to me.

But the supply of indium cannot meet our voracious demands. Indium is harvested as a byproduct of zinc mining because this so-called "hitchhiker" metal exists almost entirely in trace amounts inside deposits of other ores such as zinc and lead – sometimes as little as 1 part per million. And because indium is not mined in its own right, greater demand for it won't necessarily lead to more being mined, according to Robert Ayres, a physicist and economist at INSEAD business school in France. "Most of the indium is just single atoms stuck inside rock that can never be utilised," he says.

If the most gloomy predictions for indium are true, Ayres says the only solution is to increase recycling efforts. Because of its value, the indium recycling market is already bigger than primary production.

But a single monitor screen typically contains less than 0.5 g of ITO, so recovering such a tiny amount from electronic products is expensive and energy-intensive. "I call indium a “spice metal”, because it's sprinkled into products in a way that makes it almost impossible to recover," says Armin Reller, a materials physicist at the University of Augsburg in Germany.

So what other options do we have to indium? Finding a material that is transparent, light and conducts electricity as efficiently as ITO is a big challenge, but there are some candidates. So-called non-stochiometric tin oxides, which use the far more abundant aluminium, are one option that could be incorporated fairly easily into current manufacturing set-ups. The problem is that they do not perform as well as ITO and that tin is itself running out, with reserves estimated to last another 20-40 years.

Researchers in Germany and Japan are working on a flexible polymer-based material called PEDOT, which when doped with various chemicals becomes more transparent and a better conductor. Again, the polymer relies on non-renewable oil or coal supplies.

What’s desperately needed is a sustainable alternative, and the best solution could come in the shape of a remarkable material called graphene, the subject of a recent Nobel Prize. Like pencil-lead and diamonds, graphene is yet another form of carbon, one of the most abundant elements on Earth. Graphene's carbon atoms are arranged in a flat sheet of hexagons, like chicken wire, and this structure makes it the strongest known material and can conduct electricity as well as copper. And because graphene is just one atom thick, it is almost transparent.

Graphene may be one of the most versatile materials ever discovered – with an endless list of possibilities ranging from miniaturised computer chips to high-capacity batteries (and believe it or not for making extra-strong vodka). But one of its most-desired applications is to roll it up into carbon nanotubes and use it in touchscreens, as it offers several advantages over ITO. Graphene is more stable, so it will survive better in applications where the product will be subjected to constant physical force, such as regular finger-pounding. And graphene's superior flexibility means that it can be shaped in various configurations – you could create a spherical touchscreen, for example.

So why have we not already moved from ITO to carbon? Mark Hersam, a carbon nanotubes pioneer at Northwestern University in Illinois, believes we're waiting for an industry tipping point. "There's tremendous inertia in the electronics sector because the entire industry is modelled around ITO. Big companies like Apple are wedded to the ITO manufacturing processes and will need to invest substantially to start using carbon," he says. However, as the price of indium goes up and it becomes harder to get hold of, there is likely to be a switch."

With solar cells and electronics all competing for the same rare metal, industry is already under increasing pressure to start using a different material, whether that's another metal oxide or novel carbon chicken-wire. Looking through the breathless coverage of the iPad 3 launch on my phone, one thing is for sure: our unwavering enthusiasm for touchscreen/display-screen technologies means we desperately need to find alternatives soon.

Source

Thursday, February 23, 2012

Dolphins deserve same rights as humans, say scientists

Dolphins deserve same rights as humans, say scientists

Two dolphins at a zoo in Duisburg, Germany
Recognising the rights of dolphins would end whaling and their captivity

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Dolphins should be treated as non-human "persons", with their rights to life and liberty respected, scientists meeting in Canada have been told.

Experts in philosophy, conservation and animal behaviour want support for a Declaration of Rights for Cetaceans.

They believe dolphins and whales are sufficiently intelligent to justify the same ethical considerations as humans.

Recognising their rights would mean an end to whaling and their captivity, or their use in entertainment.

“Start Quote

Science has shown that individuality - consciousness, self-awareness - is no longer a unique human property. That poses all kinds of challenges.”

Ethics Professor Tom White Loyola Marymount University of Los Angeles

The move was made at the annual meeting of the American Association for the Advancement of Science (AAAS) in Vancouver, Canada, the world's biggest science conference.

It is based on years of research that has shown dolphins and whales have large, complex brains and a human-like level of self-awareness.

This has led the experts to conclude that although non-human, dolphins and whales are "people" in a philosophical sense, which has far-reaching implications.

'Self-aware'

Ethics expert Prof Tom White, from Loyola Marymount University, Los Angeles, author of In Defence of Dolphins: The New Moral Frontier, said dolphins were "non-human persons".

"A person needs to be an individual. If individuals count, then the deliberate killing of individuals of this sort is ethically the equivalent of deliberately killing a human being.

Intelligent cetacean behaviour

A baby bottle-nose dolphin with her mother, in a Tokyo aquarium
  • A member of a group of orcas, or killer whales, in Patagonia had a damaged jaw and could not feed. The elderly whale was fed and kept alive by its companions.
  • Dolphins taking part in an experiment had to press one of two levers to distinguish between sounds, some of which were very similar. By pressing a third lever, they were able to tell the researchers they wanted to "pass" on a particular test because it was too hard. "When you place dolphins in a situation like that they respond in exactly the same way humans do," said Dr Lori Marino. "They are accessing their own minds and thinking their own thoughts."
  • A number of captive dolphins were rewarded with fish in return for tidying up their tank. One of them ripped up a large paper bag, hid away the pieces, and presented them one at a time to get multiple rewards.
  • In Iceland, killer whales and fishermen have been known to work together. The whales show the fishermen where to lay their nets, and in return are allowed to feed on part of the catch. Then they lead the fleet to the next fishing ground.

"We're saying the science has shown that individuality - consciousness, self-awareness - is no longer a unique human property. That poses all kinds of challenges."

“Start Quote

They can look in a mirror and say, 'Hey, that's me'”

Dr Lori Marino Psychologist

The declaration, originally agreed in May 2010, contains the statements "every individual cetacean has the right to life", "no cetacean should be held in captivity or servitude, be subject to cruel treatment, or be removed from their natural environment", and "no cetacean is the property of any state, corporation, human group or individual".

It adds: "The rights, freedoms and norms set forth in this declaration should be protected under international and domestic law."

Psychologist Dr Lori Marino, from Emory University in Atlanta, told how scientific advances had changed the view of the cetacean brain.

She said: "We went from seeing the dolphin/whale brain as being a giant amorphous blob that doesn't carry a lot of intelligence and complexity to not only being an enormous brain but an enormous brain with an enormous amount of complexity, and a complexity that rivals our own."

Dolphins had a sense of self which could be tested by the way they recognise themselves in mirrors, she added.

"When you get up in the morning and look in the mirror and know that's you, you have a sense of 'you'," said Dr Marino.

"They have a similar sense. They can look in a mirror and say, 'Hey, that's me'."

Source

Monday, February 13, 2012

Masdar - the carbon neutral city

Masdar - the carbon neutral city

Powered by the sun, cooled by wind, the car-free environment of Masdar is working to become the world's first carbon neutral city in the United Arab Emirates.

Fiona Foster investigates whether the city is a model for the future or just a green mirage.

Get in touch with Fast Track via email or Facebook.

Watch Fast Track on the BBC World News channel on Saturdays at 04:30, 13:30 and 19:30 GMT or Sundays at 06:30 GMT.

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Monday, January 9, 2012

Leopard in deadly attack in Indian city of Guwahati

Leopard in deadly attack in Indian city of Guwahati

Wild leopard attacks man in Gauhati (07/01/12)
One of the victims, Kripesh Dey, was badly injured in the attack

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One person has been killed and several others injured in an attack by a leopard in the Indian state of Assam.

The man died after the leopard attacked several people in a densely populated area of the city of Guwahati.

The leopard strayed into the Shilpukhuri area of the city on Saturday and attacked residents, one of whom died the next day of his injuries.

The animal has now been released into the Manas Wildlife Sanctuary, forest officials said.

For the people of Guwahati, bomb blasts and other terror attacks were not uncommon till recently, because of repeated attacks by the secessionist United Liberation Front of Assam (Ulfa), but a leopard straying into a town is rare, particularly during the day.

Chased out

The leopard was first sighted on Saturday morning near a crematorium in the town.

As the funeral of a Congress Party leader's son was going on, the place was full of dignitaries, ministers and other VIPs.

Police sent them to a safer place and chased the leopard out, but it turned towards the Shilpukhuri residential area.

"First, it jumped across several multi-storey buildings, including a bank, then jumped on to the ground," said Manas Paran, photojournalist for the Sunday Indian magazine and an eyewitness.

Local people armed with sticks and iron rods tried to chase the leopard away. The enraged animal then started attacking locals, Mr Paran told BBC.

Mr Paran kept following the big cat at extremely close quarters to get good pictures for his magazine.

Deb Kumar Das, aged around 50, was one of the first people whom the leopard clawed at. He suffered severe wounds to the head, ear and neck.

He was treated in hospital but later returned home, where he was found dead on Sunday.

Several others suffered the ire of the big cat. One of them, Kripesh Dey, had part of his scalp removed in the attack.

Later, when the leopard entered a shop, locals locked it up. Forest officials and vets reached the scene after some time with tranquilisers and were able to capture it.

"After it was tranquilised and treated in Guwahati Zoo, we released it in the Manas Wildlife Sancturary today", said Utpal Borah, head of the zoo.

This incident has once again brought to fore the conflict between humans and animals in India.

Assam's forest officials say humans are encroaching onto leopard habitats. Residential areas built right in leopard habitats have become vulnerable to such attacks.

This is the second death from leopard attacks in five years.

Source

Monday, October 24, 2011

Grow your own meat

Grow your own meat

Professor Mark Post: "The basic problem with current meat production is that it's inefficient"

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Mark Post has been given €300,000 to make a hamburger, in one year. Easy money, you might think, but try doing that without using meat that has come from an animal.

Professor Post is one of the few people on the planet who can. As head of the department of vascular physiology at Maastricht University in the Netherlands, he is in the vanguard of a new wave of research to create a way of producing meat that cuts out the need for animal husbandry altogether.

Ideas that could change the world

Some ideas, some technologies may sound like science fiction, but they are fast becoming science fact. In our eight-part series we will be exploring ideas that are the future of technology.

Instead of getting meat from animals raised in pastures, he wants to grow steaks in lab conditions, directly from muscle stem cells. If successful, the technology will transform the way we produce food. "We want to turn meat production from a farming process to a factory process," he explained.

Prof Post is not the first to dream this dream. In the mid 20th Century, Dutchman Willem van Eelen - back then a budding medical student - dreamt of creating meat without killing animals, by using stem cells.

A stem cell is a special type of cell capable of replicating itself many many times and differentiating into specialised cell types, such as muscle cells.

Dr van Eelen pursued his dream for decades, but made little progress. Then in 1999 he was granted a patent on the idea and slowly the world started to take notice.

In 2002, NASA took a passing interest in the idea and funded Morris Benjaminson at Touro College, New York, to investigate making meat from muscle cells as a way to feed astronauts on deep space journeys.

Dr Benjaminson removed a sample of cells from the muscle of a goldfish and managed to grow it outside the fish's body. The fillet was marinated in garlic, lemon, pepper and olive oil and deep-fried. A panel of testers inspected the fillet and said it smelt and looked just like the real thing, but they weren't allowed to eat it because of US laws prohibiting consumption of experimental products.

Unfortunately, NASA decided there were easier and cheaper ways to feed astronauts, and stopped funding Dr Benjaminson.

In 2005 Dr van Eelen finally convinced the Dutch government to support research into test tube meat to the tune of €2 million.

A series of projects were set up. One explored how embryonic stem cells could be coaxed to become muscle cells, a second study investigated how muscle might be made to grow larger, and a third investigated what sort of growth medium would be optimal for creating steaks in the lab. That money recently ran out and the projects were scaled down.

Then, earlier this year, an anonymous philanthropist got in touch with Prof Post, who for a while worked with Dr van Eelen's colleagues, and offered to pay him to make a hamburger out of Petri-dish pork. "It is likely the most expensive hamburger that we will ever see on this planet," said Prof Post.

Cost of farming

Why go to all that trouble? Take a look at the carbon footprint of meat production, and the justification is clear: livestock farming accounts for around 18% of all man-made greenhouse gas emissions - greater than emissions due to transport.

Cattle Breeding animals for meat is considered inefficient and damaging to the environment

The UN forecasts that world demand for meat will double by 2050, making that problem much worse. On top of this, around 80 per cent of all farmland is devoted to meat production, and cattle consume around 10 per cent of the world's fresh water supplies. Farming for meat is a very costly process.

Then there is the animal welfare argument. Prof Post thinks that, deep down, most people feel the way we farm meat these days is less than satisfactory: "I think everybody knows subconsciously that the way we produce meat is not sustainable and isn't friendly to animals."

Echoing this sentiment, the animal rights organisation People for the Ethical Treatment of Animal (PETA) has announced a $1 million prize for the first company to bring synthetic meat to shops in at least six US states by 2016.

Harvest time

So how exactly is in vitro meat made? First stem cells have to be harvested from an animal. Researchers have suggested many different approaches, including enticing embryonic stem cells - the most versatile and potent of all stem cells, harvested from embryos - to differentiate into muscle cells.

“Start Quote

"I think everybody knows subconsciously that the way we produce meat is not sustainable and isn't friendly to animals”

Prof Mark Post Maastricht University

This approach has the greatest potential, because one embryonic stem cell, correctly controlled, could potentially produce many tonnes of meat.

But Prof Post believes that controlling the differentiation of embryonic stem cells is too tricky. While we have figured out how to guide embryonic stem cell development in human, rat, mouse and rhesus monkey cells, controlling the embryonic stem cells from cows and pigs has proved much more difficult. "For some reason, we can't do it and we don't know why," he said.

Instead, Prof Post is using cells called myosatellites - a form of muscle stem cell that is normally used by the body to repair damaged muscle.

Myosatellite cells can be extracted from a mature animal without killing it and have numerous advantages. Firstly, they are "one way" cells, in the sense that they can only become muscle cells.

Secondly, as the muscle cells proliferate they have an innate tendency to organise into muscle fibres. All that Prof Post has to do to form a strip of muscle is provide anchor points for the fibres to grow around, and the muscle forms by itself. "It's a bit like magic," he said.

Exercising meat

For muscle to develop properly, it has to be exercised regularly. This is why people who are bed-ridden for anything more than a few days start losing muscle bulk.

Lab created muscle tissue Meat stem cells replicate themselves and can even be made to exercise

Some researchers have experimented with giving the growing muscle tiny electric shocks to stimulate growth. Prof Post explained that this only improves growth by about 10%, and the energy needed would be too expensive to make meat produced in this way commercially viable.

Instead, he relies on the innate properties of muscle cells to exercise themselves. The anchor points - which in his current experiments are small pieces of Velcro stuck to the petri dish - provide tension in the muscle strip. Because muscle cells naturally try to contract, the anchor points provide resistance which in turn causes the muscle to put on bulk in an attempt to increase the force of contraction.

After a few weeks, the muscle cells grow into strips a couple of millimetres thick and 2-3 centimetres long. At present they cannot grow any thicker because there is no way to get oxygen and nutrients into the the cells in the centre of the strip.

If the strip was to get any thicker, those central cells would die out due to lack of oxygen and nutrients.

Long term, Prof Post plans to develop an intricate meshwork through which nutrients and oxygen can travel into the centre of the strip, allowing it to grow thicker, raising the possibility of producing a strip of muscle thick enough to be prepared like a steak. "In principle we could use any animal as a source for our meat. We could use pig meat, fish, chicken, game, any animal that has myosatellite cells in its muscles."

Now serving

For his first burger, Prof Post intends to harvest a number of these thin strips, mince them up with onion and spices, and then get a celebrity chef to cook up the hamburger. "It would be great if someone like Jamie Oliver agreed to cook it for us, and a famous actress ate it."

Jamie Oliver Prof Post hopes that celebrity chef Jamie Oliver will cook the first burger

Prof Post thinks a high profile publicity stunt is needed to change the image of in vitro meat. There's been a mixed reception to the idea so far. He wants to show the public that it is safe and fundamentally no different to eating meat from animals. "Some people think it's the same as genetically modified food, but it's not. We use exactly the same process that happens in nature."

He points out that until a couple of decades ago we bought cheese from farm houses, and yet today virtually all cheese is made in factories. "Why should meat be any different?"

Killing animals for meat may become a thing of the past, but producing meat in this way will still require some animals. "We will still have farms because we need small donor herds to provide stem cells. So there will be a low level of livestock breeding and keeping. But it will be a tiny fraction of what it is today."

Perhaps one of the trickiest hurdles that Prof Post and his colleagues are yet to overcome is the taste of in vitro meat. "We don't really know where the taste of meat comes from," he said. "We assume it comes from fat, but there may be other components, most of them are unknown so it's a bit of a mystery how the conditions we use during the culturing of the meat will affect the taste."

The only person known to have tasted in vitro meat was a Russian TV journalist who visited the lab last year. "He just grabbed it out of the dish and stuffed it into his mouth before I could say anything," said Post. The taste? "He said it was chewy and tasteless."

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Thursday, October 20, 2011

Global warming 'confirmed' by independent study

Global warming 'confirmed' by independent study

Weather station at airport
Weather stations are giving a true picture of global warming, the group found

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The Earth's surface really is getting warmer, a new analysis by a US scientific group set up in the wake of the "Climategate" affair has concluded.

The Berkeley Earth Project has used new methods and some new data, but finds the same warming trend seen by groups such as the UK Met Office and Nasa.

The project received funds from sources that back organisations lobbying against action on climate change.

"Climategate", in 2009, involved claims global warming had been exaggerated.

Emails of University of East Anglia (UEA) climate scientists were hacked, posted online and used by critics to allege manipulation of climate change data.

Fresh start

The Berkeley group says it has also found evidence that changing sea temperatures in the north Atlantic may be a major reason why the Earth's average temperature varies globally from year to year.

Saul Perlmutter
The group includes physicist Saul Perlmutter, a Nobel Prize winner this year

The project was established by University of California physics professor Richard Muller, who was concerned by claims that established teams of climate researchers had not been entirely open with their data.

He gathered a team of 10 scientists, mostly physicists, including such luminaries as Saul Perlmutter, winner of this year's Nobel Physics Prize for research showing the Universe's expansion is accelerating.

Funding came from a number of sources, including charitable foundations maintained by the Koch brothers, the billionaire US industrialists, who have also donated large sums to organisations lobbying against acceptance of man-made global warming.

“Start Quote

Our biggest surprise was that the new results agreed so closely with the warming values published previously”

Richard Muller Berkeley group founder

"We were concerned that the climate scientists were not putting all their data into the public domain, whether using Freedom of Information rules or anything else," he told BBC News.

"Science should be open, and data should be open, as a matter of principle."

The group's work also examined claims from "sceptical" bloggers that temperature data from weather stations did not show a true global warming trend.

The claim was that many stations have registered warming because they are located in or near cities, and those cities have been growing - the urban heat island effect.

The Berkeley group found about 40,000 weather stations around the world whose output has been recorded and stored in digital form.

It developed a new way of analysing the data to plot the global temperature trend over land since 1800.

What came out was a graph remarkably similar to those produced by the world's three most important and established groups, whose work had been decried as unreliable and shoddy in climate sceptic circles.

Graph
The Berkeley group's record of global land temperature mirrors existing ones closely

Two of those three records are maintained in the US, by the National Oceanic and Atmospheric Administration (Noaa) and National Aeronautics and Space Administration (Nasa).

The third is a collaboration between the UK Met Office and UEA's Climatic Research Unit (CRU), from which the e-mails that formed the basis of the "Climategate" furore were hacked two years ago.

"Our biggest surprise was that the new results agreed so closely with the warming values published previously by other teams in the US and the UK," said Professor Muller.

"This confirms that these studies were done carefully and that potential biases identified by climate change sceptics did not seriously affect their conclusions."

Since the 1950s, the average temperature over land has increased by 1C, the group found.

They also report that although the urban heat island effect is real - which is well-established - it is not behind the warming registered by the majority of weather stations around the world.

They also showed that in the US, weather stations rated as "high quality" by Noaa showed the same warming trend as those rated as "low quality".

'Time for apology'

Professor Phil Jones, the CRU scientist who came in for the most personal criticism during "Climategate", was cautious about interpreting the Berkeley results because they have not been published in a peer-reviewed journal.

"I look forward to reading the finalised paper once it has been reviewed and published," he said.

Professor Phil Jones The findings so far provide validation for Phil Jones, targeted during the "Climategate" affair

"These initial findings are very encouraging, and echo our own results and our conclusion that the impact of urban heat islands on the overall global temperature is minimal."

The Berkeley team has chosen to release the findings initially on its own website.

They are asking for comments and feedback before preparing the manuscripts for formal scientific publication.

In part, this counters the accusation made during "Climategate" that climate scientists formed a tight clique who peer-reviewed each others' papers and made sure their own global warming narrative was the only one making it into print.

But for Richard Muller, this free circulation also marks a return to how science should be done.

"That is the way I practised science for decades; it was the way everyone practised it until some magazines - particularly Science and Nature - forbade it," he said.

"That was not a good change, and still many fields such as string theory practice the traditional method wholeheartedly."

This open "wiki" method of review is regularly employed in physics, the home field for seven of the 10 Berkeley team.

Bob Ward, policy and communications director for the Grantham Institute for Climate Change and the Environment in London, said the warming of the Earth's surface was unequivocal.

"So-called 'sceptics' should now drop their thoroughly discredited claims that the increase in global average temperature could be attributed to the impact of growing cities," he said.

"More broadly, this study also proves once again how false it was for 'sceptics' to allege that the e-mails hacked from UEA proved that the CRU land temperature record had been doctored.

"It is now time for an apology from all those, including US presidential hopeful Rick Perry, who have made false claims that the evidence for global warming has been faked by climate scientists."

Ocean currents

The Berkeley group does depart from the "orthodox" picture of climate science in its depiction of short-term variability in the global temperature.

The El Nino Southern Oscillation (ENSO) is generally thought to be the main reason for inter-annual warming or cooling.

But by the Berkeley team's analysis, the global temperature correlates more closely with the state of the Atlantic Multidecadal Oscillation (AMO) index - a measure of sea surface temperature in the north Atlantic.

There are theories suggesting that the AMO index is in turn driven by fluctuations in the north Atlantic current commonly called the Gulf Stream.

The team suggests it is worth investigating whether the long-term AMO cycles, which are thought to last 65-70 years, may play a part in the temperature rise, fall and rise again seen during the 20th Century.

But they emphasise that anthropogenic global warming (AGW) driven by greenhouse gas emissions is very much in their picture.

"Had we found no global warming, then that would have ruled out AGW," said Professor Muller.

"Had we found half as much, it would have suggested that prior estimates [of AGW] were too large; if we had found more warming, it would have raised the question of whether prior estimates were too low.

"But we didn't; we found that the prior rise was confirmed. That means that we do not directly affect prior estimates."

The team next plans to look at ocean temperatures, in order to construct a truly global dataset.

Source

Saturday, October 15, 2011

Trees 'boost African crop yields and food security'

Trees 'boost African crop yields and food security'

Tree and crop mixed planting (Image: World Agroforestry Centre)
The nitrogen-fixing roots of certain trees provide valuable nutrients to resource-poor arable land

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Planting trees that improve soil quality can help boost crop yields for African farmers, an assessment shows.

Fertiliser tree systems (FTS) also help boost food security and play a role in "climate proofing" the region's arable land, the paper adds.

Researchers from the World Agroforestry Centre say poor soil fertility is one of the main obstacles to improving food production in Africa.

The results appear in the International Journal of Agricultural Sustainability.

"In Africa, it is generally agreed that poor soil management - along with poor water management - is most greatly affecting yields," explained co-author Frank Place, head of the centre's Impact Assessment team.

He said that despite chemical fertilisers having been on the market for more than half a century, farmers appeared reluctant or unable to buy them.

"Therefore, there have been a lot of attempts to bring in other types of nutrients from other systems - such as livestock and plants" he told BBC News.

"We have been working quite a lot on what is broadly referred to as 'fertiliser tree systems'."

Although it has been known for centuries that certain plants, such as legumes, "fix" nitrogen in the soil and boost food crop yields, Dr Place said that the centre's researchers had been looking to develop a more active management approach such as FTS.

“Start Quote

In TFS across Africa as a whole, yields are doubling or more in two-thirds of cases”

Frank Place WAC

"Some farms, for example in Zambia, where the farms are larger, it is possible to rest arable land and allow it to lie fallow," he observed.

"But in place such as much of Malawi, where population densities are higher, they cannot afford to fallow their land; so we came up with alternative management systems where they could intercrop the trees with the (maize)."

While the technique is not new, Dr Place said that some of the nitrogen-fixing species used by farmers were probably not the most effective.

For example, farmers in East Africa had been using Cajanus cajan (also known as pigeon pea).

"A lot of the nitrogen was being stored in the trees' seeds; so there was an effort to use other trees that put a greater volume in the soil, such as Gliricidia sepium (one of its common name is mother of cocoa)," he said.

"A really nice thing about G. sepium is that we have been coppicing some of those trees for 20 years and they still continue to grow back vigorously."

What is 'nitrogen-fixing'?

Gliricidia sepium (Image: World Agroforestry Centre)
  • The atmosphere consists of about 80% nitrogen, but plants cannot use it in this form
  • Certain plants, such as legumes, have bacteria growing in their root hairs that convert it into a form that plants can use
  • This form of nitrogen is know as "green manure" and is a nutrient that helps plants, such as food crops, to grow

(Source: World Agroforestry Centre)

However, he acknowledged that there were a number of challenges that had to be addressed in order to maximise yields.

For example, some systems suggested planting rows of trees between rows of crops with mixed results.

"We realised that there were a few management problems with that sort of system - what tended to happen was that there was too much competition between the crops and the trees," Dr Place explained.

"We developed a new management system where the trees were cut very low to the ground at the time you are planting the crop so then there was no light competition.

"The trees go into a dormant state when you cut them like this, so the root system is not competing straight away for the nutrients, so the maize is free to become established.

"The trees only really start to come out out of the dormant phase when the maize is already tall."

Another challenge was to provide enough seeds in order to have mass-scale planting. He said that balancing the provision of high-quality seeds with large local engagement was another hurdle that had to be overcome.

But the rewards in improved yields were noticeable, he added.

"Some of the studies have shown that in TFS across Africa as a whole, yields are doubling or more in two-thirds of cases."

Where the systems were not delivering such good results, Dr Place said that scientists were looking to refine current practices and modify them to suit the local conditions.

'Climate proofing'

As well as helping to boost yields, the use of trees in agriculture has other benefits - such as helping to "climate proof" agriculture land.

One example, Dr Place said, was the use of Faidherbia albida (common names include winter thorn and apple-ring acacia) in West African arable landscapes.

"It has a deep penetrating tap root, and it can secure a good water supply even in dry years," he explained.

"Generally speaking, tree roots do go much deeper than crop roots, so it is recycling nutrients and water from deeper reaches.

"There are also studies showing that these roots act as conduits and bring up water to surface root systems (such as those belonging to crops)."

The editor-in-chief of the International Journal of Agricultural Sustainability, Professor Jules Pretty from Essex University in , said the study illustrated that there was a growing movement of agricultural innovations across Africa that were increasing yields and at the same time improving the environment.

"Trees and shrubs in agricultural systems seem to break some of the rules of agriculture - in this case, farmers are using shrubs to create a diverse rotation pattern rather than year-on-year maize," he told BBC News.

"The trees fix nitrogen and improve the soil; the leaves can be fed to livestock; the crops then benefit greatly in subsequent years."

Source

Sunday, October 9, 2011

New Zealand oil ship leak 'raises questions'

New Zealand oil ship leak 'raises questions'

Bruce Anderson, Maritime New Zealand: "It has the potential to be a significant environmental impact"

Related Stories

New Zealand's Prime Minister John Key says "serious questions" must be answered about why a container ship ran aground on a reef off one of the country's most spectacular coastlines.

Oil leaking from the Liberian-flagged Rena has created a 5km (3 mile) slick.

An all-out effort is under way to remove nearly 2,000 tonnes of oil from the vessel, which is stranded 12 nautical miles off the coast.

Heavy swells and gale-force winds are forecast for the area from Monday.

Officials says 20-30 tonnes of oil have already spilled into the Bay of Plenty, one of the country's top tourist destinations, since the MV Rena ran aground on Wednesday.

If the ship breaks up, it could release 1,700 tonnes of heavy fuel into an area that is home to whales, dolphins, seals, penguins and a variety of other birds.

'Working tirelessly'

John Key, who flew over the scene in a helicopter on Sunday, said two inquiries to determine why the ship had collided with the Astrolabe Reef were already under way.

"People know about the reef, and for it to plough into it for no particular reason - at night, in calm waters - tells you something terrible has gone wrong and we need to understand why," he told Radio New Zealand.

Map

Four naval vessels and two barges are in the area to try to contain the spill.

The barges have already begun scooping up the oil that has spilled into the sea, the BBC's Duncan Kennedy reports from Australia.

A third ship is alongside the MV Rena and attempts are under way to hook them up so the oil can be transferred off the stricken ship.

But the process of linking up the two ships is tricky in the calmest of conditions, and will be all but impossible in gale-force winds and heavy swells, our correspondent adds.

And, because one end of the ship is stuck on the reef while the other floats free, the oncoming storm brings another fear for rescue teams.

"Once you increase the swell, the upsurge, the lift on the aft end of the ship will increase, and the chances of her separating start to rise," explained Marine Risk Assessor John Riding.

“Start Quote

"From tip to toe, they are covered in black sticky gunk, matting up all their feathers right down to the skin”

Brett Gartrell Wildlife Health Centre

The MV Rena's owners, Greece-based Costamare Inc, said it was "working tirelessly" on the response.

"Minimising any impact to New Zealand's coastline is the absolute priority," the firm said in a statement. "The current primary focus of the salvage operations is the safe transfer of the vessel's fuel oil from her tanks."

Our correspondent says that the next 48 hours will determine whether this incident can be contained or become a serious environmental disaster.

Exclusion zone

The department of conservation has established two wildlife rescue centres and dispatched teams to scour the beaches and islands of the Bay of Plenty looking for oil-covered animals and birds.

The maritime authorities has said a total of eight oiled birds, including little blue penguins, had been recovered and taken to a wildlife facility in Te Maunga.

"From tip to toe, they are covered in black sticky gunk, matting up all their feathers right down to the skin," said Brett Gartrell, of New Zealand's Wildlife Health Centre. "They have ingested it and started to get anaemic which is part of the toxic effect of the oil."

Officials say they are preparing for the possibility the slick will hit the coast, after dispersants sprayed from aircraft proved ineffective.

"It has the potential to be very, very serious indeed, simply because of the age of the ship, the damage she's sustained," Andrew Berry of Maritime New Zealand (MNZ) said.

MNZ has established a one-kilometre maritime exclusion zone around the ship and warned that the fuel oil is toxic.

The animal welfare group Forest and Bird said the timing of the accident, in the middle of the breeding season for birds, was "disastrous".

Source

Friday, October 7, 2011

Millions stroll in New York's 'park in the sky'

Millions stroll in New York's 'park in the sky'

Help

One of the runaway hits of this past summer in New York has not been on Broadway - instead it has been at a most unusual park which is attracting millions of visitors from all around the world.

The disused elevated railway track that runs through downtown Manhattan now offers commuters and tourists alike a peaceful escape from the chaos on the busy city streets below.

The inside story of New York City's so-called "park in the sky'' is about to be told in a book called High Line.

Michael Maher took a stroll through the park to find out more.

Source

Go to the source to watch the amazing video about "The High Line" :)

Monday, October 3, 2011

Vast shark sanctuary created in Pacific

Vast shark sanctuary created in Pacific


Environment correspondent, BBC News
"Sharks now banned" underwater photoshoot
The Marshall Islands initiative is the latest in a worldwide islands' movement to protect sharks

Related Stories

The Marshall Islands government has created the world's largest shark sanctuary, covering nearly two million sq km (750,000 sq miles) of ocean.

The Pacific republic will ban trade in shark products and commercial shark fishing throughout its waters.

Tourism, including diving, is a staple of the Marshall Islands archipelago, which is home to just 68,000 people.

Sharks and their near relatives such as rays are seriously threatened by issues such as habitat loss and fishing.

“Start Quote

The momentum for protecting these animals continues to spread across the globe”

Matt Rand Pew Environment Group

About a third of ocean-going sharks are on the internationally-recognised Red List of Threatened Species.

"In passing this [shark protection] bill, there is no greater statement we can make about the importance of sharks to our culture, environment and economy," said Senator Tony deBrum, who co-sponsored the bill through the Marshallese parliament.

"Ours may be a small island nation, but our waters are now the biggest place sharks are protected."

To put the sanctuary in context, it covers roughly the same area as Indonesia, Mexico or Saudi Arabia, and is about eight times bigger than the UK.

The move will extend the area of ocean in which sharks are protected from about 2.7 million sq km to 4.6 million sq km (1.0 to 1.8 million sq miles).

Global network

Under the bill, commercial shark fishing and any trade in shark products will be banned, and any of the fish accidentally caught must be released alive.


Whale shark
The sanctuary will swallow a huge chunk of the Pacific Ocean


Certain designs of fishing gear will be banned from Marshallese waters; and violators of all these measures face fines of up to £200,000.

The Marshallese government has worked on the plan with advisors from the Pew Environment Group, the US-based organisation that identified archipelago nations as providing big marine conservation "wins" because of the vast scale of their territorial waters.

"We salute the Republic of the Marshall Islands for enacting the strongest legislation to protect sharks that we have seen," said Matt Rand, Pew's director of global shark conservation.

"As leaders recognise the importance of healthy shark populations to our oceans, the momentum for protecting these animals continues to spread across the globe."

The Marshall Islands follows the lead taken by Palau two years ago, whose sanctuary was then the world's biggest. Other nations including the Bahamas have since followed suit.

Last week, a group of eight countries including Mexico, Honduras, the Maldives and Northern Mariana Islands signed a declaration announcing they would push for more shark protection across the world.

Because they grow and reproduce relatively slowly, sharks are especially vulnerable to factors such as accidental or targeted fishing.

Shark protection measures are also likely to help marine biodiversity overall, as they restrict the rights of fishing vessels and require greater scrutiny of landings.

However, with the Marshall Islands as with Palau and some other countries, there are questions over the capacity of authorities to monitor fully such huge expanses of ocean.

Source

~~~~~~~~~~~~

Commentary

For anyone unsure of the benefit of sharks and why we should protect them, I'll give small rundown as to why this sanctuary is beneficial.

Sharks limit other animals from eating away natural resources too quickly. The herbivores that sharks feed on eat the producers. The only protection producers have are the sharks that, as carnivores eating herbivores, keep the other animals in check and stop them from destroying the natural ecosystem, keeping the environment sustainable.

Think of a shark as a diet on a group of herbivores. That diet keeps the environment fit and healthy and sustains it, rather than allowing all the herbivores to destroy their environment and eat all the natural resources around them.

Sharks are very beneficial in this way and are crucial to the harmony of the ecosystems of our world. The majority of them also do not eat humans and are not aggressive towards humans.

Sunday, September 18, 2011

Siemens to quit nuclear industry

Siemens to quit nuclear industry

siemens building
Siemens will continue to work in the power industry but drop out of the nuclear sector

Related Stories

German industrial and engineering conglomerate Siemens is to withdraw entirely from the nuclear industry.

The move is a response to the Fukushima nuclear disaster in Japan in March, chief executive Peter Loescher said.

He told Spiegel magazine it was the firm's answer to "the clear positioning of German society and politics for a pullout from nuclear energy".

"The chapter for us is closed," he said, announcing that the firm will no longer build nuclear power stations.

A long-planned joint venture with Russian nuclear firm Rosatom will also be cancelled, although Mr Loescher said he would still seek to work with their partner "in other fields".

Siemens was responsible for building all 17 of Germany's existing nuclear power plants.

But more recently, the firm has limited itself to providing the non-nuclear parts of plants being built by other firms, including current projects in China and Finland.

The latest decision appears to imply a step back from building "conventional islands" - the non-nuclear plant in nuclear power stations - an area in which Siemens has remained active.

However, Mr Loescher also said Siemens would continue to make components, such as steam turbines, that are used in the conventional power industry, but can also be used in nuclear plants.

U-turn

He also gave his backing to the German government's planned switch to renewable energy sources, calling it a "project of the century" and claiming Berlin's target of reaching 35% renewable energy by 2020 was achievable.

The German chancellor, Angela Merkel, announced at the end of May that all of the country's 17 nuclear reactors would be shut down by 2022.

Before the Fukushima disaster, nuclear power accounted for 23% of electricity production in Germany.

The German government's decision marked a complete U-turn by the chancellor, who only in September 2010 had announced that the life of existing nuclear plants would be extended by an average of 12 years.

Siemen's move, announced on Sunday, is also a turnaround.

In 2009, the firm withdrew from an eight-year-old nuclear joint venture with French energy firm Areva, shortly before announcing its new deal with Rosatom.

"In view of global climate change and the increasing power demand worldwide, for us nuclear energy remains an essential part of a sustainable energy mix," Mr Loescher had said at the time.

Source

Tuesday, September 6, 2011

Probe pictures Moon landing sites

Probe pictures Moon landing sites

Apollo 17 landing site
Apollo 17: The wheels of the Lunar Roving Vehicle ("Moon buggy") left parallel lines in the "soil"

Related Stories

Remarkable new images of the Apollo landing sites on the Moon have been released by Nasa.

The pictures clearly show the hardware left on the lunar surface by American astronauts in the 1960s and 70s, including Apollo 17's "Moon buggy".

The images were acquired by the robotic Lunar Reconnaissance Orbiter (LRO), which has been circling Earth's satellite since 2009.

Such shots have been returned before, but these are the best yet.

LRO has recently lowered its orbit from 50km above the Moon's surface to just 25km.

This makes it easier to see equipment, such as the descent stages that put the astronauts on the surface. Some of the science experiments are visible, also - as are the trails of bootmarks left in the dirt as the crews positioned these science packages.

LRV Apollo 17 Harrison Schmitt sits in the LRV

The Apollo 17, 14 and 12 sites are the focus of the latest release.

They were viewed by the narrow-angle imaging system on LRO's Lunar Reconnaissance Orbiter Camera (LROC) instrument.

At the lower altitude, this instrument sees objects at a resolution of 25cm by 25cm per pixel.

In an extreme blow-up of the Apollo 17 Lunar Roving Vehicle (LRV), it is just possible to discern the condition in which the astronauts Eugene Cernan and Harrison Schmitt parked the buggy - with its wheels turned to the left.

LRO has been a highly productive mission. It has now returned several hundred thousands pictures of the lunar surface.

The probe was originally conceived as a robotic precursor to future manned missions. However, when Nasa might return to the lunar body with astronauts is not clear. Last year, US politicians cancelled the project, known as Constellation, that was intended to achieve this feat.

"We all like to obsess and look at the Apollo landing site images because it's fun," said Mark Robinson, the LROC principal investigator from Arizona State University, Tempe.

LRO artist's impression LRO was launched in 2009

"People actually used to be able to go to the Moon; people used to explore the Moon - and hopefully sometime in the future that will continue again. But LROC is looking at the whole Moon and we've taken about 1,500 of these high-resolution images distributed all around the Moon… and this is just a huge resource for anybody studying the Moon, doing science; and engineers planning to go back to the Moon in general and to specific sites."

Erosion processes on the Moon work much slower than on an active planet like Earth. Eventually, though, all traces of the Moon landings will be erased.

The lunar body is constantly bombarded by micrometeorites that will, in time, mix up the boottracks and break down the equipment. It has been estimated that rock at the surface erodes at a rate of about 1mm per million years.

"In human years, it may seem like forever, but in geologic terms probably there will be no traces of the Apollo exploration in let's say 10 to 100 million years," said Dr Robinson.

On Thursday, Nasa will launch its latest Moon mission - the Gravity Recovery and Interior Laboratory (Grail).

This is a pair of satellites that will survey the Moon's gravity in unprecedented detail. The data will reveal its internal structure, helping to explain how the lunar body formed and why its nearside now looks so different from its farside.

Source

Monday, September 5, 2011

Who, What, Why: How are hurricanes named?

Who, What, Why: How are hurricanes named?

Satellite image of Hurricane Katia
Katia, the second hurricane of the season, is gaining strength in the Atlantic

The US is still clearing up after Irene, while dealing with Lee and keeping an eye on the looming threat of Katia. So how are hurricanes and other tropical cyclones named?

Hurricane Katia has gathered strength in the Atlantic just as Tropical Storm Lee has soaked Mississippi and whipped up wildfires in Texas.

And before the end of the year, the US and the Caribbean could have Tammy, Vince and Whitney blowing through their midst.

Putting human names, rather than numbers or technical terms, to tropical cyclones is intended to avoid confusion and make them easier to remember when issuing warnings. But who comes up with them?

Contrary to rumour, it's nothing to do with the names of politicians or, even more outlandishly, the people who died in the Titanic.

The list of names for the Atlantic's tropical cyclones, which are upgraded to hurricanes if they reach 74mph (119km/h), was originated in 1953 by the National Hurricane Center in Miami.

But it is maintained and updated by the World Meteorological Organization, an agency of the United Nations based in Geneva.

It has five tropical cyclone regional bodies around the world, and the one that covers the US and Caribbean is called the RA IV Hurricane Committee. It has 26 members.

The Answer

  • The World Meteorological Organization has five regional committees that update the names
  • They reflect the sensibilities of the region
  • Notorious names are retired and replaced

The committee decides at an annual meeting, usually held in March or April, which storms from the previous year have been particularly devastating and therefore need to be "retired" and replaced.

This year it was farewell to Igor and Tomas, to be replaced by Ian and Tobias.

The list is alphabetical, so the first tropical cyclone of 2011 was called Arlene, the next Bret and so on.

Each year the names rotate to the next of six lists, and the first named storm of a season always begins with the letter "A".

The rotation policy means that the names of 2011 may be familiar to those who followed the weather closely in 2005. That year Katrina, which claimed nearly 2,000 lives in the US, was replaced by Katia, currently whipping up a storm a few hundred miles from Bermuda.

Koji Kuroiwa, chief of the tropical cyclones programme at the World Meteorological Organization, says the US military was the first to use people's names to denote storms, during World War II.

Recently retired

  • 1992: Andrew
  • 1999: Floyd
  • 2004: Ivan
  • 2005: Katrina
  • 2008: Gustav

"They preferred to pick out names from girlfriends or wives or mothers. Most in those days were female names."

This principle was formally introduced in 1953, with men's names added in the 1970s.

Using personal names is intended to make it easier for people to understand forecasts and warnings, says Mr Kuroiwa, but the public sometimes likes to have its say.

"We have a lot of enquiries every year requesting, 'Please use my name or my wife's name or my daughter's name'.

“Start Quote

The key feature is that it's a name that people can remember and identify”

Julian Heming Met Office

"In the meantime, there's some negative comment, for example a woman named Irene who wasn't very happy."

In Victorian times, storms were named arbitrarily. An Atlantic storm that ripped off the mast of a boat named Antje in 1842 became known as Antje's hurricane.

Other hurricanes have been identified by their location, but their latitude and longitude was not easy to identify or communicate.

A 19th Century Australian forecaster, Clement Wragge, is reported to have amused himself by naming them after unpopular politicians. Hurricanes in the Caribbean region were once named after the saints' days on which they struck.

Nowadays, the names differ worldwide according to the region.

"They generally try to cover names which are in general usage, either in the US or the surrounding island nations in the Caribbean," says Julian Heming, tropical predictions scientist at the Met Office in the UK.

WHO, WHAT, WHY?

Question mark

A part of BBC News Magazine, Who, What, Why? aims to answer questions behind the headlines

"So they include names which have a Hispanic feel as well, like Jose. In the Atlantic and East Pacific they use real people's names but there are different conventions in other parts of the world."

In the western Pacific, where Typhoon Talas has killed scores of people this week, they use names of objects and descriptive adjectives, says Mr Heming. They include Son-Tinh, Faxai and Noru.

"The key feature is that it's a name that people can remember and identify. Previously that region had names that were very American/English and it was decided 10 years ago that they needed to be more appropriate to the region."

Five letters - Q, U, X, Y and Z - are not used in the Atlantic list due to a lack of names, so there are a maximum of 21 named storms in one year before the list is exhausted.

"If the remainder of the season is very active, it's not out of the question that we'll have to go through the same process as 2005," says Mr Heming, "and start using letters from the Greek alphabet."

Source

Friday, September 2, 2011

Space junk at tipping point, says report

Space junk at tipping point, says report

Artist's impression of debris in low Earth orbit, released by the European Space Agency (ESA)
Artist's impression from the European Space Agency of debris in low Earth orbit

Related Stories

Scientists in the US have warned Nasa that the amount of so-called space junk orbiting Earth is at tipping point.

A report by the National Research Council says the debris could cause fatal leaks in spaceships or destroy valuable satellites.

It calls for international regulations to limit the junk and more research into the possible use of launching large magnetic nets or giant umbrellas.

The debris includes clouds of minuscule fragments, old boosters and satellites.

Some computer models show the amount of orbital rubbish "has reached a tipping point, with enough currently in orbit to continually collide and create even more debris, raising the risk of spacecraft failures," the research council said in a statement on Thursday.

Situation 'critical'

Hopes of limiting the amount of space junk in orbit suffered two major setbacks in recent years.

In 2007, China conducted an anti-satellite weapon test which destroyed a decommissioned weather satellite, smashing the object into 150,000 pieces larger than 1cm.

The International Space Station The International Space Station sometimes has to dodge orbital debris

Two years later, two satellites - one defunct and one active - crashed in orbit, creating even more debris.

"Those two single events doubled the amount of fragments in Earth orbit and completely wiped out what we had done in the last 25 years," said Donald Kessler, who led the research.

There are 22,000 pieces of debris large enough to track from the ground, but smaller objects could still cause serious damage.

The International Space Station must occasionally dodge some of the junk, which flies around the Earth at speeds of up to 17,500 mph (28,164 km/h).

In June, some debris narrowly missed the space station, forcing its six crew to go to their escape capsules and prepare for an emergency evacuation back to Earth.

The situation is critical, said Mr Kessler, a retired Nasa scientist, because colliding debris creates even more of the junk.

"We've lost control of the environment," he said.

The report makes no recommendations about how to clean up the field of debris.

But it refers to an earlier study for the Pentagon's science think-tank, the Defence Advanced Research Projects Agency (Darpa).

The Darpa report, dubbed "Catcher's Mitt", suggested a range of technologies, including harpoons, nets and an umbrella-shaped device that would sweep up the debris.

The aim would be to push the debris further towards the earth where it would burn up, or into a higher but safer orbit.Link

Source

Saturday, August 27, 2011

Subterranean Amazon river 'is not a river'

Subterranean Amazon river 'is not a river'

Underground river
The underground flow is nothing like those sometimes found in caves

A subterranean river said to be flowing beneath the Amazon region of Brazil is not a river in the conventional sense, even if its existence is confirmed.

The "river" has been widely reported, after a study on it was presented to a Brazilian science meeting last week.

But the researchers involved told BBC News that water was moving through porous rock at speeds measured in cm, or inches, per year - not flowing.

Another Brazilian expert said the groundwater was known to be very salty.

Valiya Hamza and Elizabeth Tavares Pimentel, from the Brazilian National Observatory, deduced the existence of the "river" by using temperature data from boreholes across the Amazon region.

The holes were dug by the Brazilian oil company Petrobras in the search for new oil and gas fields, and Petrobras has since released its data to the scientific community.

Using mathematical models relating temperature differences to water movement, the scientists inferred that water must be moving downwards through the ground around the holes, and then flowing horizontally at a depth of several km.

“Start Quote

The word 'river' should be burned from the work - it's not a river whatsoever”

Jorge Figueiredo Petrobras geologist

They concluded that this movement had to be from West to East, mimicking the mighty Amazon itself.

A true underground river on this scale - 6,000km (4,000 miles) long - would be the longest of its kind in the world by far.

But Professor Hamza told BBC News that it was not a river in the conventional sense.

"We have used the term 'river' in a more generic sense than the popular notion," he said.

In the Amazon, he said, water was transported by three kinds of "river" - the Amazon itself, as water vapour in atmospheric circulation, and as moving groundwater.

"According to the lithologic sequences representative of Amazon [underground sedimentary] basins, the medium is permeable and the flow is through pores... we assume that the medium has enough permeability to allow for significant subsurface flows."

Glacial progress

The total calculated volume of the flow - about 4,000 cubic metres per second - is significant, although just a few percent of the amount of water transported by the Amazon proper.

Amazon mouth The underground flow could be confirmed with coastal measurements, scientists suggest

But the speed of movement is even slower than glaciers usually display, never mind rivers, not rivers.

And whether water really is transported right across the region in this way is disputed by Jorge Figueiredo, a geologist with Petrobras.

"First of all, the word 'river' should be burned from the work - it's not a river whatsoever," he told BBC News.

Water and other fluids could indeed flow through the porous sedimentary rock, he said, but would be unlikely to reach the Atlantic Ocean because the sedimentary basins containing the porous rock were separated by older rock deposits that would form an impermeable barrier.

"But the main problem is that at depths of 4,000m, there is no possibility that we have fresh water - we have direct data that this water is saline," said Dr Figueiredo.

"My colleagues and I think this work is very arguable - we have a high level of criticism."

End of the affair?

Press reports suggested Professor Hamza was optimistic about confirming his results over the next few years using more direct methods.

But, he said, this was not the case.

"It is well known that geothermal methods are better suited for determining flows with [such small] velocities," he said.

"At lower velocities, experimental techniques may pose considerable difficulties."

It may be possible to examine directly sediments transported into the Atlantic by the subterranean flow, he said, noting that a zone of relatively fresh water extends into the ocean near the mouth of the Amazon.

The research - Indications of an Underground "River" beneath the Amazon River: Inferences from Results of Geothermal Studies - was presented at the 12th International Congress of the Brazilian Geophysical Society in Rio de Janeiro, and has not been published in a peer-reviewed scientific journal.

The team has named the underground flow the "Hamza River".

Source