A Science News Aggregator That Covers Stories in the World Of Science And Technology.
Wednesday, December 9, 2009
Paper Battery Could Power Gadgets Of The Future
From the Daily Mail:
Ordinary paper could one day be used as ultra-lightweight, bendable batteries, according to scientists from Stanford University.
Simply coating a sheet of paper with ink made of silver and carbon nanomaterials makes an efficient storage device that is 10 times as powerful as lithium-ion batteries used to power laptops.
Read more ....
Mysterious Light Display Leaves Norwegians And Astronomers Puzzled
From Popular Science:
A Russian missile test or a meteor remain the top guesses for a strange spiraling light phenomenon.
A bizarre spiraling light show over Norway has raised speculations ranging from a Russian rocket test to an odd meteoric display. The Norwegian Meteorological Institute remains unsure of the phenomenon's origins, but astronomers have said that it does not appear connected to the Aurora Borealis, also known as the Northern Lights.
Read more ....
‘Testosterone’s Aggressive Impact Is A Myth. It Makes You Friendlier’
It is popularly known as the selfish hormone, which courses through male veins to promote egotistical and antisocial behaviour. Yet research has suggested that testosterone’s bad reputation is largely undeserved.
Far from always increasing aggression and greed, the male hormone can actually encourage decency and fair play, scientists have discovered.
The common belief that it makes people quarrelsome, however, can cause it to have that effect. When people think they have been given supplements of the hormone they tend to act more aggressively, even though it does nothing biological to promote such behaviour.
Read more ....
'Small Wind' Market To Double By 2013, Study Says
From Green Tech/CNET News:
Individuals and commercial businesses around the world are increasingly drawn to small wind turbines to supplement energy consumption, according to a report released Wednesday by Pike Research.
The niche industry of small wind turbines, which saw $165 million in revenue in 2008 and $203 million in 2009, will grow to $412 million by 2013, according to Pike's "Small Wind Power" report.
The Smoking Gun At Darwin Zero
From Watts Up With That?:
People keep saying “Yes, the Climategate scientists behaved badly. But that doesn’t mean the data is bad. That doesn’t mean the earth is not warming.”
Let me start with the second objection first. The earth has generally been warming since the Little Ice Age, around 1650. There is general agreement that the earth has warmed since then. See e.g. Akasofu . Climategate doesn’t affect that.
Read more ....
Life On Mars Theory Boosted By New Methane Study
From Science Daily:
Science Daily (Dec. 8, 2009) — Scientists have ruled out the possibility that methane is delivered to Mars by meteorites, raising fresh hopes that the gas might be generated by life on the red planet, in research published in Earth and Planetary Science Letters.
Read more ....
Colossal Flood Created The Mediterranean Sea
From Live Science:
The Mediterranean Sea as we know it today formed about 5.3 million years ago when Atlantic Ocean waters breached the strait of Gibraltar, sending a massive flood into the basin.
Geologists have long known that the Mediterranean became isolated from the world's oceans around 5.6 million years ago, evaporating almost completely in the hundreds of thousands of years that followed.
Read more ....
TV Chosen Over Longer Life: Poll
From The Montreal Gazette:
What would you refuse to give up even if it added five healthy years to your life? According to many Canadians, you can put television on that list — and don’t try to take away booze or red meat, either.
Some 55 per cent of the respondents to a poll for RBC Insurance said they would not give up indulgences such as watching television, red meat (45 per cent) and alcohol (34 per cent), even if it would add five healthy years to their lives.
Read more ....
Doctors Query Ability Of Tamiflu To Stop Severe Illness
Photograph: Leonhard Foeger/Reuters
From The Guardian:
Review published in British Medical Journal accuses flu drug manufacturer Roche of withholding evidence from trials.
Roche, the manufacturer of Tamiflu, has made it impossible for scientists to assess how well the anti-flu drug stockpiled around the globe works by withholding the evidence the company has gained from trials, doctors alleged today .
A major review of what data there is in the public domain has found no evidence Tamiflu can prevent healthy people with flu from suffering complications such as pneumonia.
Read more ....
A Hot Piece of Hardware: NASA’s New Orbiter Will Map the Entire Sky in Infrared
From Discover Magazine:
Stars and other astronomical phenomena radiate across the electromagnetic spectrum, on both sides of the puny band of visible light that the human eye can pick up. NASA’s newest toy, set for a Friday launch into space, will map the infrared portion of that radiation—and do it across the entire sky.
Read more ....
Five Ways To Revolutionise Computer Memory
From New Scientist:
Once upon a time, not so long ago, the idea that you might store your entire music collection on a single hand-held device would have been greeted with disbelief. Ditto backing up all your essential computer files using a memory stick key ring, or storing thousands of high-resolution holiday snaps in one pocket-sized camera.
What a difference a decade makes. The impossible has become possible thanks to the lightning rise of a memory technology with the snazzy name of "flash".
Read more ....
Sobering News: Coffee Increases Drunkenness
Drinking coffee does not sober you up – and may actually further impair your judgement, new research suggests.
The combination of alcohol and caffeine produces a potentially lethal mix that just makes it harder to realise you are actually drunk in the first place.
And the study published in Behavioural Neuroscience suggests popular caffeinated energy drinks could also raise risks from intoxication rather than lessen them.
Read more ....
Google Launches Real-Time Search With Instant Twitter And Facebook Updates
From The Daily Mail:
Google has launched 'real-time' search to give users up-to-the-second information.
The search engine will update its information at the same rate as it receives it, which means postings on sites such as Twitter and Facebook will appear immediately at the bottom of the page.
The new data - from more than a billion pages on the web - will scroll past in real-time, without any need to refresh the page. Users can also stop the page from continually scrolling by clicking on the 'stop updating' phrase.
Read more ....
To Save Soldiers on The Battlefield, Darpa Invests In Suspended Animation
From Popular Science:
An active battlefield is a really inconvenient place to lose a lot of blood. But naturally that's exactly where soldiers sustain the bulk of their life-threatening injuries, so Darpa is committing $9.9 million to finding drugs that can extend the "golden hour" -- the one-hour window that medics generally have to bring a soldier back from severe blood loss -- by as much as six hours.
Read more ...
Hubble Sees Most Distant Galaxies
From BBC:
Nasa's Hubble Space Telescope (HST) has captured its deepest view of the Universe, producing images of galaxies that have never been seen before.
The pictures were acquired by the HST's new Wide Field Camera 3 (WFC3).
This highly sensitive camera can see starlight from far-off objects - light that has been "stretched" by the expanding Universe.
Read more ....
Tuesday, December 8, 2009
Untold Levels Of Oil Sands Pollution On Athabasca River Confirmed
ScienceDaily (Dec. 8, 2009) — After an exhaustive study of air and water pollution along the Athabasca River and its tributaries from Fort McMurray to Lake Athabasca, researchers say pollution levels have increased as a direct result of nearby oil sands operations.
University of Alberta biological sciences professor David Schindler was part of the team that conducted a long term air and water study and found high levels of Polycyclic Aromatic Compounds. PACs are a group of organic contaminants containing several known carcinogens, mutagens, and teratogens. The highest levels of PAC's were found within 50 kilometres of two major oil sands up graders.
Read more ....
Humans Have Hidden Sensory System
The human body may be equipped with a separate sensory system aside from the nerves that gives us the ability to touch and feel, according to a new study.
Most of us have millions of different types of nerve endings just beneath the skin that let us feel our surroundings. However, the once-hidden and recently discovered skin sense, found in two patients, is located throughout the blood vessels and sweat glands, and most of us don't even notice it's there.
Read more ....
Rutan And Branson Make A Giant Leap For Space Tourism
From L.A. Times:
The intergalactic entrepreneurs unveil the VSS Enterprise, the world's first commercial passenger spacecraft. Tests are expected to start early next year, and flights could begin in 2011.
On a wind-tossed desert night, the dream of space pioneers Richard Branson and Burt Rutan to bring space flight to everyone -- at least everyone who can afford it -- drew closer to reality when the pair unveiled the world's first commercial passenger spacecraft.
Read more ....
Using Rust To Capture CO2 From Coal Plants
From Technology Review:
Process could capture carbon more cheaply.
Researchers at Ohio State University are developing a novel process for generating electricity from coal that also promises to make capturing carbon-dioxide emissions cheaper. The work is being done with the help of a $5 million grant from the U.S. Department of Energy's new Advanced Research Projects Agency-Energy. The technology has been proven in laboratories; researchers will use the new funds to demonstrate it in a 250-kilowatt, pilot-scale power plant.
Read more ....
U.S. EPA Moves On Emissions As Congress Stalls
From Scientific American:
WASHINGTON (Reuters) - The U.S. Environmental Protection Agency formally declared that greenhouse gases endanger human health Monday, allowing President Barack Obama to show his commitment to act as a major climate change summit opened in Copenhagen.
The ruling by the EPA, widely expected after it issued a preliminary finding earlier this year, will allow the agency to regulate planet-warming gases even without legislation in the U.S. Congress.
Read more ....
The Secrets Of Tutankhamun's Decaying Tomb
From The Independent:
Scientists mount inquiry into how millions of visitors to Egyptian boy king's chamber are destroying the wonder they came to see, reports Guy Adams.
Given the peace and quiet Tutankhamun enjoyed for three millennia, it has been a rough 87 years for him since he was discovered by Howard Carter in 1922. He was immediately relieved of his treasures; his tomb became one of the world's best-known tourist attractions, and finally, in 2005, his mummified corpse was hoiked out of its final resting-place to be studied by scientists.
Read more ....
First Look at Virgin Galactic's SpaceShipTwo
From Discovery News:
After two years of construction, Virgin Galactic's SpaceShipTwo has been shown to the public for the first time. The first of a planned fleet of six SpaceShipTwo's has been named Virgin Space Ship (VSS) Enterprise.
Read more ....
MIT Plans To Rebuild Artificial Intelligence From The Ground Up
From Popular Science:
After 50 years and countless dead ends, incremental progress, and modest breakthroughs, artificial intelligence researchers are asking for a do-over. The $5 million Mind Machine Project (MMP), a patchwork team of two dozen academics, students and researchers, intends to go back to the discipline's beginnings, rebuilding the field from the ground up. With 20/20 hindsight, a few generations worth of experience, and better, faster technology, this time researchers in AI -- an ambiguous field to begin with -- plan to get things right.
Read more ....
Optimism As Artificial Intelligence Pioneers Reunite
From The New York Times:
STANFORD, Calif. — The personal computer and the technologies that led to the Internet were largely invented in the 1960s and ’70s at three computer research laboratories next to the Stanford University campus.
One laboratory, Douglas Engelbart’s Augmentation Research Center, became known for the mouse; a second, Xerox’s Palo Alto Research Center, developed the Alto, the first modern personal computer. But the third, the Stanford Artificial Intelligence Laboratory, or SAIL, run by the computer scientist John McCarthy, gained less recognition.
Read more ....
Draft Text Divides Climate Summit
Documents leaked at the UN climate summit reveal divisions between industrialised and developing countries over the shape of a possible new deal.
Campaigners say a draft text proposed by the Danish host government would disadvantage poorer nations.
It also sees everything coming under a single new deal, whereas an alternative text from developing countries wants an extension to the Kyoto Protocol.
Other blocs are expected to release their own texts in the next few days.
Read more ....
New Project In Scramble To Save Vanishing Internet Links
From Times Online:
The Internet Archive is fighting to preserve shortened web links created by free online services that may be running out of money.
What if, the next time you went on the internet, you clicked on a link and nothing happened?
What if billions of internet links all stopped working at once?
As 2010 approaches, this is exactly the problem that the internet is facing. So great is the concern that the Internet Archive in the United States has already begun what some people are calling one of the most important repair jobs in the web’s history.
Read more ....
Undocumented Volcano Contributed to Extremely Cold Decade From 1810-1819
From Science Daily:
Science Daily (Dec. 7, 2009) — South Dakota State University researchers and their colleagues elsewhere in America and in France have found compelling evidence of a previously undocumented large volcanic eruption that occurred exactly 200 years ago, in 1809. The discovery helps explain the record cold decade from 1810-1819.
Read more ....
Killer Petunias And Murderous Potatoes Revealed
From Live Science:
Petunias and potatoes may actually be carnivorous plants, scientists now suggest.
Indeed, carnivorous behavior may be far more widespread in plants than commonly thought — if we take a closer look, botanists said.
At least six different kinds of killer plants have been recognized since the time of Darwin, such as Venus flytraps, which snares insects between its jaw-like leaves, and pitcher plants, which capture victims in slippery pits. These plants apparently target animals to supplement their growth in harsh, nutrient-poor habitats.
Read more ....
"Very Likely" The Warmest Decade On Record
Watch CBS News Videos Online
From CBS:
At Copenhagen Climate Summit, U.N. Weather Agency also says 2009 Probably Warmest Year in Some Areas.
(CBS/AP) This decade has very likely been the warmest in the historical record, and 2009 will probably end up as one of the warmest years, the U.N. weather agency announced Tuesday at the second day of the 192-nation climate conference in Copenhagen.
In some areas - parts of Africa, central Asia - this will probably be the warmest year, but overall 2009 "is likely to be about the fifth-warmest year on record," said Michel Jarraud, secretary-general of the World Meteorological Organization.
Read more ....
Google's Real-Time Search Ready To Challenge Bing
From PC World:
Google on Monday unveiled its real-time search capability, the latest salvo in its ongoing feature war with Bing. Microsoft's search engine already integrates real-time Twitter and Facebook results. Now, both search engines have released their initial real-time products, and there's a lot to like from the two major search brands. Let's take a look at how Bing's Twitter search matches up against Google's real-time search.
Read more ....
Breakthrough Flu Drug Might Already Exist
From Technology Review:
Fragments of known drugs could lead to a more robust antiviral for H1N1 and other flu variants.
The flu virus is a wily target, constantly mutating to avoid attack from the immune system and from antiviral drugs like Tamiflu. But in research presented Sunday at the annual meeting of the American Society for Cell Biology (ASCB) in San Diego, scientists announced a new method for fighting pandemic influenzas such as H1N1 (swine) and H5N1 (avian).
Read more ....
Dolphins, Sea Lions To Serve As Marine Guardians Of Naval Base
From Scientific American:
The newest batch of sentries at Naval Base Kitsap-Bangor will be paid in fish.
The newest batch of sentries at Naval Base Kitsap-Bangor will not have to wear uniforms. But they won't get to clock out for breaks -- and they will be paid in fish.
The base near Washington's Puget Sound is slated to receive up to 20 Navy-trained bottlenose dolphins and California sea lions to patrol the shoreline around the submarine base as part of a bolstered security initiative started after the Sept. 11, 2001, terrorist attacks.
Read more ....
3 Bets the DOE Is Placing On Science To Break The Climate Stalemate
From Wired Science:
The Advanced Research Projects Agency for energy put out its second call for new ideas, and this time, the agency has narrowed its focused to three research fields.
The new arm of the Department of Energy, which is dedicated to high-risk, high-reward innovations, is betting $100 million on batteries for cars, new materials for capturing carbon, and microorganisms that can convert sunlight and carbon dioxide directly into fuels.
Read more ....Volcanic Blast's Devastation Confirmed By Pollen
From Discovery News:
A massive volcanic explosion in Indonesia rocked the planet 73,000 years ago, cooling temperatures and devastating populations of our ancestors.
It takes a heck of a disaster to wipe the trees off of India. But 73,000 years ago, the titanic eruption of Toba in Indonesia did exactly that, according to a new study, brushing the region clean almost overnight as it kicked the planet into a cold snap that would persist for almost 2,000 years.
Read more ....
Google Chief: Only Miscreants Worry About Net Privacy
'If you don't want anyone to know, don't do it'.
If you're concerned about Google retaining your personal data, then you must be doing something you shouldn't be doing. At least that's the word from Google CEO Eric Schmidt.
"If you have something that you don't want anyone to know, maybe you shouldn't be doing it in the first place," Schmidt tells CNBC, sparking howls of incredulity from the likes of Gawker.Read more ....
Dueling E-Book Readers
Watch CBS News Videos Online
From CBS News:
Natali Del Conte Compares Five Top Offerings of This Holiday Season.
(CBS) One of this year's hot gift items is the e-book reader -- portable digital devices used to read books and magazines.
They started taking off in 2001, but were very basic. Today, they're sophisticated, interactive and can perform more functions than just holding text -- and they're experiencing explosive growth.
Read more ....
Monday, December 7, 2009
Single-Atom Transistor Discovered
From Science Daily:
Science Daily (Dec. 7, 2009) — Researchers from Helsinki University of Technology (Finland), University of New South Wales (Australia), and University of Melbourne (Australia) have succeeded in building a working transistor, whose active region composes only of a single phosphorus atom in silicon.
Read more ....
Scientists: Northern Forests Need Saving, Too
From Live Science:
When fire destroys forests, or when discarded wood products are burned at the dump, carbon dioxide (CO2) escapes into the air. Hence, in part, the uproar denouncing the slash-and-burn destruction of tropical jungles. But let’s not overlook another great woodland biome: the boreal forest.
That’s the plea voiced in a recent opinion paper by Corey J.A. Bradshaw of the University of Adelaide in Australia and two colleagues. They point out that far northern forests represent a third of all remaining woodlands and 30 percent of all terrestrially stored carbon on Earth. Those vast coniferous tracts covering much of Alaska, Canada, Scandinavia, and Russia are still relatively unscathed, but they face increasing threats.
Read more ....
MIT Harnesses Online Crowds To Beat Darpa Balloon Challenge In Just 9 Hours
after the first balloons went up DARPA
From Popular Science:
The Pentagon's DARPA agency wanted to know how to filter trustworthy information from social networks; MIT had the answer.
Groups of friends and strangers spent more than a month preparing for perhaps the greatest social networking competition in history. All wanted to be the first to find 10 red weather balloons scattered across the continental U.S. on December 5, and claim a $40,000 prize from the Pentagon's DARPA agency.
Read more ....
My Comment: That was fast .... it also tells everyone that the power of social networks should not be ignored.
Personalised Vaccines Could Protect All Children
From New Scientist:
CHILDREN whose genetic make-up means they may not be protected by the standard form of a vaccine could in future be given a personalised shot. This is the prospect raised by the discovery of gene variants that seem to predict whether an individual will produce enough antibodies in response to a vaccine to protect them against disease.
Read more ....
Childhood Obesity Linked To Mutant Gene
From The Telegraph:
Childhood obesity could be caused by a genetic mutation, scientists at Cambridge University believe.
Findings show for the first time that the condition can be a genetic one, rather than the result of over feeding.
The study could have a major impact on the decision of social services to take obese children into care where they believe they are being abused.
Read more ....
Computer Pop-Ups Waste Time Even After They Have Disappeared
From The Daily Mail:
The annoyance of computer screen pop-ups lasts long after they have disappeared or been closed, research has found.
Although they might stay on the screen for just a few seconds, pop-ups make us lose more time trying to find our place and resume the task that was interrupted, a Cardiff University study concluded.
The research, led by Dr Helen Hodgetts and Professor Dylan Jones, examined the cost of on-screen interruptions in terms of the time taken to complete a simple seven-step computer task.
Read more ....
Ancient Site Reveals Signs Of Mass Cannibalism
From The BBC:
Archaeologists have found evidence of mass cannibalism at a 7,000-year-old human burial site in south-west Germany, the journal Antiquity reports.
The authors say their findings provide rare evidence of cannibalism in Europe's early Neolithic period.
Up to 500 human remains unearthed near the village of Herxheim may have been cannibalised.
The "intentionally mutilated" remains included children and even unborn babies, the researchers say.
The German site was first excavated in 1996 and then explored again between 2005 and 2008.
Read more ....
Should You Treat Your Children Like Dogs?
From The Guardian:
Can dog-whisperering techniques used to control canines also work with children?
On parenting blogs, websites and Twitter, the guilty admissions are all the same: the training techniques of Cesar Millan, AKA "The Dog Whisperer", work on kids too. Millan has published four books; his show runs on a perpetual reel on the National Geographic channel. "As I watched him work with an extremely aggressive pit bull," admits a woman called TheMentorMom on Minti.com, "I saw that some of his techniques and philosophies applied to teaching children."
Read more ....
Google Launches Real-Time Search
Search-engine giant Google Inc. on Monday disclosed partnerships with social Web-sites Facebook and MySpace, and unveiled new technology that enables it to incorporate most-current updates by users of those social networks into its results.
Google said its real-time search technology will feature a scrolling list of near-instantaneous updates from a wide range of other sources, including micro-blogging service Twitter, news sites and documents.
Read more ....
Mammoth Extinction Altered Ecosystem
From Cosmos:
SYDNEY: The extinction of mammoths in North America at the end of the last ice age was not caused by a change in the ecosystem: it's what triggered the changes, a new study suggests.
The study also elucidates a possible cause for the demise of mammoths and mastodons 15,000 years ago, and researchers say that the expanded incidence of fire in the landscape - suspected of being caused by human arrival - only appeared after the extinction.
Read more ....
Headed Toward Extinction: The Light Bulb
From CBS News:
I come not to praise the incandescent light bulb. I come to bury it.
The familiar incandescent Edison bulb debuted 130 years ago, on December 31, 1879. And the next day, its death spiral will begin. Australia has imposed regulations that will phase the bulb out in 2010 and the European Union will follow in 2012.
The U.S. meanwhile, will get rid of them through new efficiency regulations in stages. 100-watt incandescents will vanish in 2012, followed by 75-watts a year later and 60-watts a year after that.
Read more ....
Superbright Supernova Is First Of Its Kind
From Science Daily:
Science Daily (Dec. 5, 2009) — An extraordinarily bright, extraordinarily long-lasting supernova named SN 2007bi, snagged in a search by a robotic telescope, turns out to be the first example of the kind of stars that first populated the Universe. The superbright supernova occurred in a nearby dwarf galaxy, a kind of galaxy that's common but has been little studied until now, and the unusual supernova could be the first of many such events soon to be discovered.
Read more ....
Skin Cream Secrets Revealed
Credit: dreamstime
From Live Science:
If asked to describe how skin cream feels, you might use words like "smooth," "thick," or "greasy."
But for Ohio State University mechanical engineering professor Bharat Bhushan, these words aren't good enough. Using a special instrument, he has gleaned new understanding of how these creams interact with skin on the nanoscale, bringing a more quantitative measure to the smooth sensation.
Read more ....
The Tech That Makes New Airplanes And Runways Safer
From Popular Mechanics:
In our Anatomy of a Plane Crash feature, PM investigates the causes behind Air France 447's disappearance. Here are some of the advances in technology for airports, cockpits and airframes—systems that work in tandem to make air flight safer.
Read more ....
In 2010, The Civilian Space Industry Finally Takes Off
From Popular Science:
Who needs the space shuttle? Take a tour inside the private space industry and its innovative, efficient plans to get astronauts into space when NASA retires its old ride.
For a traveler heading up the highway toward the Mojave Air and Space Port, in the desert 70 miles north of Los Angeles, the surroundings are ghostly. Silent 747s and DC-10 jumbo jets from defunct airlines, along with smaller 727s and DC-9s, some cut up or resting on pylons, are visible from miles away, looking frozen and forlorn. Parked along the road at the airport entrance is a 1962 Convair 990, which began its life as an American Airlines jet airliner. Now the wind whistles through its nacelles and birds nest in its wheel wells.
Read more ....
Large Moon Of Uranus May Explain Odd Tilt
From New Scientist:
Please try to resist the childish jokes, but the fact is that the odd tilt of Uranus may be the result of a particularly large moon.
Uranus spins on an axis almost parallel with the plane of the solar system, rather than perpendicular to it – though why it does this nobody knows. One theory is that the tilt is the result of a collision with an Earth-sized object, but this "hasn't succeeded in explaining much of anything", says Ignacio Mosqueira of the SETI Institute in Mountain View, California. Why, for example, are the orbits of Uranus's 27 known moons not also tilted?
Read more ....
Earth Much More Sensitive To Global Warming Than Thought
From The Telegraph:
The Earth may be 50 per cent more sensitive to the warming effect of carbon dioxide greenhouse gas than has previously been thought, scientists claim.
A new study suggests bigger cuts in carbon dioxide (CO2) emissions may be needed to prevent drastic long term climate change.
The evidence was obtained by scientists looking back three million years to the Pliocene epoch, when global temperatures were 5.4F (3C) to 9F (5C) higher than they are today.
They found that levels of CO2 in the atmosphere at the time should not have produced such a warm world.
Read more ....
Copenhagen Climate Change Summit To Produce As Much CO2 As An African Country
From The Daily Mail:
It is being hyped as the summit that will save the planet.
But according to critics, next week's climate change talks in Copenhagen are more likely to cost the earth.
Researchers have estimated that the bill for the 12-day jamboree will top £130million - and will generate as much greenhouse gas as an entire Africa country.
Read more ....
Copenhagen Summit Urged To Take Climate Change Action
Danish Prime Minister Lars Loekke Rasmussen has described the UN climate summit in Copenhagen as an "opportunity the world cannot afford to miss".
Opening the two-week conference in the Danish capital, he told delegates from 192 countries a "strong and ambitious climate change agreement" was needed.
About 100 leaders are to attend the meeting, which is intended to supplant the 1997 Kyoto Protocol.
The UN says an unprecedented number of countries have promised emissions cuts.
Read more ....