The bright light was spotted at abut 6:45 a.m. and was bright enough to be categorized as a fireball, he said.
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"Meteors are called fireballs when they are brighter than Venus," said Peterson.

Meteors are common over Colorado but this one was unusual because it was so bright it could be seen as the sky was getting light, Peterson said.

"This one may have been much brighter (than most), more like the brightness of the moon," he said. "Events like that happen every year or so."

Peterson, who operates a Web site on meteors, said he received several witness reports but did not see the meteor himself.

"It was still burning as passed out of view at the lower horizon," wrote one 7News viewer from Dillon. "Normally they come down and flame out long before they get to the horizon."

Peterson said any debris from the meteor would be hard to find.

"You'd just be looking at a handful of rocks," he said. "The rocks would have probably fallen somewhere where there's a lot of other rocks."

Peterson said if any part of the fireball did make it to the ground it might be in northwest Colorado, in the vicinity of Meeker.

Around 50 passengers were rescued when their boat capsized in stormy waters off Batangas province about 120 kilometers (75 miles) south of Manila. They piled onto the vessel despite the bad weather after being stranded on Mindoro Island for two days.

"We were irked at some of the foreigners. They tried to save their baggage first," one passenger, Sheryl Nartates, told a local radio station after three coast guard boats picked all the passengers up.

On the resort island of Boracay, the famous white sands were littered with debris after high winds tore up roofs and trees.

"Some people are crying because they are afraid and in shock," said Roselle Gallano, a waitress at a coffee shop close to the beach front. "Many houses were damaged, some have been tilted."

The governor of nearby Aklan province said one person had been killed on Boracay and at least four were still missing.

Authorities evacuated around 90,000 residents, most of them in Albay province, where more than 1,000 people are feared dead after Typhoon Durian wiped out villages in a torrent of landslides and flash flooding in late November.

Utor, the fifth typhoon to hit the Philippines since September, did not directly hit Albay but the bereaved remain stranded in schools and makeshift shelters and the province is still without power.

On Friday, the Philippines hastily postponed an annual summit of 16 Asian leaders until January, citing concerns the typhoon could wreak havoc at the venue on the central island of Cebu. Utor subsequently swept north of Cebu.

The NDCC said over 500 houses were destroyed and electricity was knocked out in wide areas in the Visayas region.

Storms regularly hit the Philippines. In one of the worst disasters in recent years, more than 5,000 people died on the central island of Leyte in 1991 in floods triggered by a typhoon.

Major General Robert Lee, the state's director of Civil Defense, says Hawaii is nowhere close to declaring an end to the disaster period.

Senator Daniel Inouye's office says the earthquake assistance money would have helped repair the Lower Hamakua Ditch, the Waimea Irrigation System and the Upper Hamakua Ditch on the Big Island.

Inouye blames majority Republicans for cutting the earthquake relief money after the White House issued a veto threat.

He says the matter will be addressed again next year when Democrats assume control of Congress.

This was the second major flare from the same group of sunspots. Another flare spewed out from the group on Tuesday. The fact that this region of the Sun spewed out two major flares just a day apart "implies that there must have been some kind of tremendous energy buildup", Balasubramaniam told New Scientist.

The buildup of energy is thought to be related to the twisting of the Sun's magnetic field. Such a large buildup and release of energy on the Sun is a rare occurrence, and especially unusual around solar minimum, when the Sun is normally at its quietest.
Low point

The Sun appears to be just past the lowest point in its cycle, Balasubramaniam says. The last maximum was in 2000, but the exact time between maximum and minimum varies from cycle to cycle.

The last time a similar blast wave was seen by the NSO telescope was in November 2003, though it might have missed others if they occurred when the Sun was not visible from the site, he says.

The expanding blast wave also caused two dark filaments to disappear as it passed by, one at upper left and the other at lower middle. The filaments are arches of relatively cool material clinging to magnetic field lines above the Sun.

The passage of the wave may temporarily disperse this material, Balasubramaniam says. See a video showing the brief disappearance of the filaments.

Exactly how the release of magnetic energy leads to solar outbursts is not known. Whether flares provide the trigger for the waves or the relationship is more complicated is also not clear. "If we see a lot more of these, it will tell us a lot more about why these things happen at certain times," he says.

The team survey the seabed for 1,500 square kilometres at the depth of 1,000 to 2,800 metres at the a continental rim about 3,00 kms away from Phuket.

He said the team detected four mud volcanoes in the area.

The first volcano is about 200 kms away from Phuket and its base is about 1-km long in diameter and is 100 metre high. It is located about 650 metres under the sea.

The second volcano is located 50 kms west of the first volcano and is about 1,000 metres under the sea. The third and fourth volcanoes are located about 60 kms northeast of the second volcano and are about 700 to 800 metres under the sea.

Managers apologised for any fears aroused by the mishap, which occurred after water was injected at high pressure into a five-km-deep (16,000-feet-deep) borehole, but said the experiment posed no danger, SDA reported.

The Basel public prosecutor launched an investigation into the government-subsidised project after the quake in the historic city, it said.

The 80-million-franc (US$66.95 million) experiment, known as "deep heat mining", is designed to extract enough super-heated water to drive a power plant providing electricity for 10,000 homes and heat for 2,700 others.

We forget now that the American environmental movement was born not in reaction to smog or to dirty water, but to dams. That John Muir, the great conservationist of the first half of the twentieth century, founded the Sierra Club to fight the dam at Yosemite's Hetch Hetchy, and that David Brower, Muir's successor, built the club into the prototype of modern activism in the struggles over dams at Dinosaur National Monument, Glen Canyon, and the Grand Canyon. We forget because our big-dam days are over -- almost everything that could be plugged with concrete long since has been. But the rest of the world is still deep in these fights. In fact, in many places they still define both environmentalism and development, as journalist Jacques Leslie's superb account, Deep Water: The Epic Struggle Over Dams, Displaced People, and the Environment (Farrar, Straus and Giroux, 2006), makes clear.

Leslie has written a volume that is heir, both in organization and in power, to Encounters With the Archdruid, John McPhee's classic profile of Brower and his fight against dam-nation, much of which was written from deep within the canyons of the Colorado. Leslie chronicles three people whose lives have been shaped by the fight over dams. One is a full-out opponent, one an ambivalent expert, and one a bureaucrat trying to deal with the legacy left to him by a century of dams.

The first -- and most beautifully wrought -- portrait is of Medha Patkar, an Indian woman who has been battling the Narmada Dam for decades. Narmada has become the prototype of the big third-world dam: expensive, environmentally ruinous, and essentially impossible to stop. Patkar and her activist group, Narmada Bachao Andolan, came incredibly close -- they forced the World Bank for the first time to back down from funding a dam.

But India was too committed to the plan to be deterred. By a 2-to-1 vote of the Indian supreme court the project went ahead in 2000, and as Leslie's account opens, Patkar has been reduced to trying to keep the dam from going higher. Her favorite tactic: to chain herself to a piece of ground and wait for the waters to rise, daring the authorities to let her drown. This approach (used in California, too, in the fight over the Stanislaus River a quarter of a century ago) draws its inspiration from Gandhi, but Leslie's brilliant and unsparing portrait makes it clear that Patkar is not the happy warrior that we remember the Mahatma to be. Leslie searches for the source of her incredible courage and commitment, talking to her family and the friends of her younger life, and traces much of her relentless drive to the unhappiness of her early marriage, where her obvious talents were suffocated. When she finally left, says one friend, "she was at her lowest level, very depressed.... She couldn't see what she could do."

For Leslie, that description clicked. "Medha's suffering preceded her [Narmada] career. She did not suffer because anti-dam activism required suffering. She suffered first, then found a meaningful expression for it in the valley. Suffering became her fuel and her power and her validation, the proof of her commitment to the cause and the source of her magnetism."

This is convincing, and it describes a fair number of talented activists I've known over the years. It's also the stuff of a great novel, especially as it is deftly interwoven with the suffering of the people whose lives are being wrecked by the rising waters. Its operatic quality sets a bar that the rest of the book never quite meets; Leslie's other characters are less troubled, less charismatic. They retire, they don't try to kill themselves.

Still, their stories are remarkable. Thayer Scudder, "the world's leading dam resettlement expert," has spent an entire career studying dam resettlement as an anthropologist and working as a consultant for international agencies like the World Bank to evaluate new projects -- always hoping for what Leslie calls "one good dam." His first project, as a young anthropologist in the 1950s, was the Kariba Dam on the Zambezi River along what is now the Zambia-Zimbabwe border. It was the first big dam the World Bank ever financed, and it turned into a horror story of everything that could possibly go wrong, especially the resettlement project that Scudder chronicled. At first the Tonga tribespeople refused to believe their villages would be inundated -- how could a wall on the river accomplish that? When they were finally forced away (only after many of their spear-clutching men were massacred by police) it was to barren, unfamiliar, and droughty land. Leslie visits there 45 years later and finds the villagers are still hoping that the dam will be taken down and that they can return to their homes, or at least that Scudder will come back and explain how it all happened. (He can't bear to, perhaps because of the many children in the community named for him or his wife, Molly.) One old man summed up the mood: "There is nothing to do," he said. "Just sit and wait. Maybe die."

Though it's done the Tonga no good, their suffering, at least for a time, helped turn the tide of dam-building in Africa. Chastened by his experience, Scudder became more militant in demanding better resettlement plans before dams could be approved. In fact, he played a major role in blocking a dam slated for the Okavango Delta in Botswana, and he and Leslie revisit the scene of that semi-triumph. They also spend time in Lesotho, the mountainous country surrounded by South Africa, where at the end of his career Scudder is still trying to improve resettlement plans for people who will soon be displaced by a massive dam, even as the water rises. If Patkar is a picture of unflinching courage, Scudder is the emblem of good-hearted ambivalence. He believes, theoretically, in "development," even as he concedes that almost all the dams he's earned good money helping build are, in the end, disasters. "I haven't been associated with many success stories," he said, "and the few successes have been more about stopping something than creating something." That is a chastened epitaph.

The first two-thirds of Leslie's book are mostly about how dams affect the people around them. The third section, set on Australia's Murray River, is more ecological. It tells the tale of how a century's worth of dams have degraded this splendid land even as they helped enrich its people by allowing industrial farming in a dry country. Leslie follows a bureaucrat, Don Blackmore, as he attempts to restore a (quite possibly oxymoronic) "healthy, working river." In particular, Blackmore's task is to persuade the basin's many users to allow "environmental flows" down the main stream of the Murray -- that is, to surrender some of the water now used to irrigate crops so that the ever-saltier, ever-less-living river might have a fighting chance to make a comeback.

Though Blackmore has some success -- and his story in all its particulars will be familiar to those who have followed battles over California water rights in recent decades -- it's not at all clear that the fight began in time. Leslie writes stunning descriptions of vast tracts of dying trees, of dead lagoons where aboriginals lived for tens of thousands of years on the relative fat of the land.

In the end, this book implicitly asks a question that we've mostly ignored for the last hundred years: How hard can we make the planet work for us? A dam is a way to store up the power of the natural world -- to make it water our crops and power our lives at all times instead of periodically. But it comes at a much higher price than the dam pioneers would have guessed; not just the human cost of resettlement, but the ecological costs of stilling the earth's veins and arteries.

And now, though Leslie barely mentions it (one of the very few flaws in his account), we face yet another conundrum. Hydro power is in vogue again because it produces few greenhouse gases. This is not universally true -- build a shallow reservoir in a tropical climate and the rotting vegetation will give off vast quantities of methane, a gas 20 times better at trapping heat than CO2 -- but it is one more reason to dam, to overlook the enormous costs. In the end, there's never a way to get around the question of demand. It is possible -- it is likely -- that we are asking more of the world than the world can provide. In some places that is farce (Hoover Dam gave us Las Vegas) and in other places it is tragedy. How do you decide between the need of a Chinese peasant for electricity that doesn't come from coal, and the need of the Yangtze to flow to the sea?

In a bitter and incantatory epilogue, Leslie points out that the hulking dams of our lifetime won't last forever. Sediment is already piling up behind them, and some day either earthquake or neglect will rupture them, leaving just ruins behind. "They'll be relics of the twentieth century," he writes, "like Stalinism and gasoline-powered cars, symbols of the allure of technology and its transience, of the top-down, growth-at-all-costs era of development and international banks, of the delusion that humans are exempt from nature's dominion, of greed and indifference to suffering.... They'll be reminders of an ancient time when humans believed they could vanquish nature, and found themselves vanquished instead.Tra

In a final draft of its fourth assessment report, to be published in February, the panel reports that the level of carbon dioxide in the atmosphere has accelerated in the past five years. It also predicts that temperatures will rise by up to 4.5 C during the next 100 years, bringing more frequent heat waves and storms.

The panel, however, has lowered predictions of how much sea levels will rise in comparison with its last report in 2001.

Climate change sceptics are expected to seize on the revised figures as evidence that action to combat global warming is less urgent.

Scientists insist that the lower estimates for sea levels and the human impact on global warming are simply a refinement due to better data on how climate works rather than a reduction in the risk posed by global warming.

One leading UK climate scientist, who asked not to be named due to the sensitivity surrounding the report before it is published, said: "The bottom line is that the climate is still warming while our greenhouse gas emissions have accelerated, so we are storing up problems for ourselves in the future."

The IPCC report, seen by The Sunday Telegraph, has been handed to the Government for review before publication.

It warns that carbon dioxide emissions have risen during the past five years by three per cent, well above the 0.4 per cent a year average of the previous two decades. The authors also state that the climate is almost certain to warm by at least 1.5 C during the next 100 years.

Such a rise would be enough to take average summer temperatures in Britain to those seen during the 2003 heatwave, when August temperatures reached a record-breaking 38 C. Unseasonable warmth this year has left many Alpine resorts without snow by the time the ski season started.

Britain can expect more storms of similar ferocity to those that wreaked havoc across the country last week, even bringing a tornado to north-west London.

The IPCC has been forced to halve its predictions for sea-level rise by 2100, one of the key threats from climate change. It says improved data have reduced the upper estimate from 34 in to 17 in.

It also says that the overall human effect on global warming since the industrial revolution is less than had been thought, due to the unexpected levels of cooling caused by aerosol sprays, which reflect heat from the sun.

Large amounts of heat have been absorbed by the oceans, masking the warming effect.

Prof Rick Battarbee, the director of the Environmental Change Research Centre at University College London, warned these masking effects had helped to delay global warming but would lead to larger changes in the future.

He said: "The oceans have been acting like giant storage heaters by trapping heat and carbon dioxide. They might be bit of a time-bomb as they have been masking the real effects of the carbon dioxide we have been releasing into the atmosphere.

"People are very worried about what will happen in 2030 to 2050, as we think that at that point the oceans will no longer be able to absorb the carbon dioxide being emitted. It will be a tipping point and that is why it is now critical to act to counter any acceleration that will occur when this happens."

The report paints a bleak picture for future generations unless greenhouse gas emissions are reduced. It predicts that the climate will warm by 0.2 C a decade for the next two decades if emissions continue at current levels.

The report states that snow cover in mountainous regions will contract and permafrost in polar regions will decline.

However, Julian Morris, executive director of the International Policy Network, urged governments to be cautious. "There needs to be better data before billions of pounds are spent on policy measures that may have little impact," he said.

"Such a large body of water, dropping so fast," he said.

At 27,000 square miles, the size of Ireland, Victoria is the greatest of Africa's Great Lakes - the biggest freshwater body after Lake Superior. And it has dropped fast, at least six feet in the past three years, and by as much as a half-inch a day this year before November rains stabilized things.

The outflow through two hydroelectric dams at Jinja is part of the problem - a tiny part, says the Uganda government, or half the problem, say environmentalists. But much of what is happening to Victoria and other lakes across the heart of Africa is attributable to years of drought and rising temperatures, conditions that starve the lakes of inflowing water and evaporate more of the water they have.

An extreme example lies 1,500 miles northwest of here, deeper in the drought zone, where Lake Chad, once the world's sixth-largest, has shrunk to 2 percent of its 1960s size. And the African map abounds with other, less startling examples, from Lake Turkana in northern Kenya, getting half the inflow it once did, to the great Lake Tanganyika south of here, whose level dropped over five feet in five years.

"All these lakes are extremely sensitive to climate change," the U.N. Environment Program warned in a global water assessment two years ago.

Now, in a yet unpublished report obtained by The Associated Press, an international consulting firm advises the Ugandan government that supercomputer models of global-warming scenarios for Lake Victoria "raise alarming concerns" about its future and that of the Nile River, which begins its 4,100-mile northward journey here at Jinja.

The report, by U.S.-based Water Resources and Energy Management International, says rising temperatures may evaporate up to half the lake's normal inflow from rainfall and rivers, with "severe consequences for the lake and its ability to meet the region's water resources needs."

A further dramatic drop in Victoria's water levels might even turn off this spigot for the Nile, a lifeline for more than 100 million Egyptians, Sudanese and others.

"People talk about the snows of Kilimanjaro," said Aris P. Georgakakos, the study's chief author, speaking of that African mountain's melting glaciers. "We have something much bigger to worry about, and that's Lake Victoria."

Each troubled lake is a complex story.

Lake Chad's near-disappearance, for example, stems in part from overuse of its source waters for irrigation. Deforestation around Lake Victoria, shared by Uganda, Kenya and Tanzania, makes the area a less efficient rain "catchment" for the lake, and overfishing and pollution are damaging its $400-million-a-year fishing industry. Kenya's Rift Valley lakes, some just a few feet deep, have always fluctuated in size, even drying up with drought.

But African leaders say things are different this time, because long-term climate change may eclipse other factors.

"These cycles, when they've happened, they haven't happened under the circumstances pertaining now - the global warming, overpopulation, degradation," said Maria Mutagamba, Uganda's water and environment minister.

African temperatures rose an average 1 degree Fahrenheit in the 20th century - matching the global average - and even more in the past few decades in such places as Lake Tanganyika, climatologists say. If greenhouse gases continue to build in the atmosphere, temperatures may be several degrees warmer by this century's end.

At Lake Victoria's receding shoreline, a place of scavenging storks, weedy expanses of water hyacinth, fishing boats derelict on dried lake bed, people see what's happening but don't understand why.

"In just a few years, the lake pulled back from there, maybe 60 meters (200 feet)," said fisherman Patrick Sewagude, 24, pointing to old high-water marks at Ssese Beach, near Kampala, Uganda's capital.

Someone had planted a few rows of corn on the exposed lake bed. Grass was taking over elsewhere. "It's tough. The fish have gone way out. You pull up stones in your nets," Sewagude said.

Back in Jinja, 40 miles east of Kampala, researchers at the Lake Victoria Fisheries Organization said falling water levels are the latest blow to the dying biology of Lake Victoria, where pollution has helped kill off scores of unique species of tropical fish in recent decades. Now tilapia, once a prime food fish, are declining because their inshore breeding grounds are vanishing.

"People for many years haven't seen such a sudden change in the lake level," said the fisheries office's Richard Ogutu-Ohwayo, a biologist on the lake for 35 years. "Right now it's very difficult to say what will happen. It's a grim scenario, of worldwide climate change."

Around the lake shore, everyone has his own theories.

"The water's too hot, and the fish are going deeper, beneath the nets," said Modi Kafeel Ahmed, a Jinja fish processor. But the lake has been overfished, too, he said. "If it goes like this another five years, the lake will be empty of fish."

For 30 million people living in its basin, Lake Victoria is a vital source - of livelihoods and food, of water, of transportation, of electric power.

Almost 200 miles across the lake from here, Tanzanian authorities have reduced water supplies to the city of Mwanza because an intake pipe was left high and dry. The same is happening in Uganda, where German engineer Erhard Schulte is pushing work crews to finish refitting Entebbe's city water plant, extending its intake pipe 1,000 feet farther out into the lake.

"The old Britisher who designed the original plant never expected the lake would drop this way," Schulte told a visitor.

Perhaps the worst impact is on power supplies. Tanzanian factories have shut down because the rivers powering hydroelectric dams, and replenishing Lake Victoria, are running dry. Kampala, a city of more than 1 million, has endured hours-long blackouts daily.

Uganda's two big hydro dams, side by side on the Victoria Nile, the lake's only outlet, are victims and - some say - prime suspects in the crisis.

In 2003, facing growing Ugandan demand for electricity, the Nalubaale and Kiira dams produced a peak 265 megawatts of power. In the process, their operators began overshooting long-standing formulas regulating flow of water out of the lake, an independent hydrologist later concluded.

That outside study, cited by environmentalists, contends 55 percent of the lake-level drop since 2003 is traceable to excessive outflow. But the dams' private operators and Ugandan officials strongly dispute that.

Paul Mubiru, Ugandan energy commissioner, says the dams have had a "negligible" impact on Lake Victoria, and points to Lake Tanganyika's similar fall in levels - with no dams involved.

Earlier this year, the operators announced they were reducing the dam outflows, "but our observations show that even with the reduced outflow, the water loss is still on the increase," Mutagamba, the water minister, told the AP.

Falling lake levels, meantime, mean lower "head" pressure at the dams. Their output has dropped to 120 megawatts, pushing Uganda deeper into economic crisis.

It is such unanticipated ripple effects - from abrupt environmental change - that underlie the warnings worldwide about global warming. Scientists find another unexpected example in Lake Tanganyika, where they say warmer surface waters may be depleting fish stocks.

Many African lakes go unvisited by scientists, but what is known is troubling enough, says veteran researcher Robert E. Hecky, of Canada's University of Waterloo. "It is some of the most imperative data we have, that global climate change can be affecting these African water bodies," he said.

A "very comprehensive, very realistic" study of Lake Victoria is needed, preferably conducted by U.N. specialists, said Frank Muramuzi, the head of Uganda's leading environmental organization.

"Businesses are standing still, not working. Fishermen can't get enough fish. We do not have enough water supplies," Muramuzi said. "Rains alone won't bring back the lake levels, because there would still be climate change, a lot of heat, evaporation. It's reached a point where people don't know what to do."

"This might last me through to February if I use it wisely," Rodda says, gesturing to his meagre water resources. "Some of the other blokes haven't got any water at all and they've got to truck it in to keep their stock going.

"It's the worst I've seen it in 50 years. There's been pockets of drought around Australia for the last eight years or so but in the last 12 months it's intensified, even areas that are normally OK are having a dry time of it."

Rodda's farm is in Victoria state's Wimmera district, an area renowned for its rich soil that sits in the heart of south-eastern Australia's wheat belt.

But the prosperous rural lifestyle that brought his family here in the 1920s has been transformed into a grim struggle for survival as the worst drought in a century grips Australia.

A burly man, wearing a typical Australian farmer's outfit of flannelette shirt, jeans and elastic-sided boots, Rodda gives an exasperated sigh after climbing down into his empty dam.

"Look at it," he says, crushing a sod of earth to powder in his powerful hands. "Bone dry."

Around him on the dam floor are the remains of shellfish that once lived in the waters and the occasional sheep bone poking out from the cracked earth.

Some areas of Australia have been without significant rainfall for years and figures released last week showed the country's winter crop was down more than 60 percent on 2005.

Farm incomes have also plummetted 70 percent to their lowest levels in more than a decade and Treasurer Peter Costello has warned that Australia faces a rural depression if the situation does not improve.

Rodda has already written off this year's crop after his stunted wheat stalks, normally thigh high, managed only a few inches (centimetres) growth in the parched earth.

"It's not worth taking it to market," he said. "We'll use it as feed for the sheep so we can get some use out of it."

The drought has impacted on every aspect of life in rural Australia, with many small towns now facing a slow death as businesses close and young people move to the cities.

"There was a small motor workshop here that shut down last month," Rodda said. "When times are tough, people make do with what they've got and don't buy new equipment, so this fellow's business just wasn't viable any more."

Those who remain often suffer depression as the difficulties of drought are compounded by the isolation of Australia's vast distances. The mental health charity Beyond Blue has reported a steep rise in suicides among farmers.

Even country Australia's love of sport has been affected, with some local councils scrapping football tournaments because the drought meant players risked serious injury competing on rock-hard sports fields.

Rodda's farm hand, Gilbert Fryatt, sold his own property three years ago because of the drought and now makes his living hiring himself out as a handyman and sheep shearer.

"We weren't making any money and the kids weren't interested in taking over the farm, so me and the wife thought 'why are we going on with this?'," he said.

Asked if he misses working his own land, Fryatt gives a noncommittal shrug: "These things happen."

Fryatt said a major concern for the Wimmera's farmers was that if the drought continued, winds from Australia's desert interior would lift the region's topsoil into vast dust clouds and dump it offshore, permanently eroding the area's fertility.

Despite their hardships, both Rodda and Fryatt remain determined to stay positive in the face of drought.

"You get up in the morning and say 'well all right, we're not doing things that flash. It's not raining today but we can do some dry jobs'," he said, adding ruefully. "Jeez, we've been doing a lot of dry jobs."

He said when Lake Hindmarsh, the largest freshwater lake in Victoria, dried up, a group of farmers decided to make the best of the situation by driving out onto the lake bed and having a barbecue.

Fryatt said that generations of Australian farmers had endured the country's harsh climate and there was a belief that the latest crisis, while the most severe in living memory, would eventually end.

"There's always next year," he said. "We might be doing it tough now but it only takes a good bit of rain to turn it around."

The resulting greenhouse effect heated the earth as a whole by about 9 Fahrenheit (5 Celsius) in less than 10,000 years, geologic records show.

The increase in temperatures lasted about 170,000 years, altering the world rainfall patterns, making the oceans acidic, affecting plant and animal life and spawning the rise of our modern primate ancestors, according to the study by Mark Pagani, associate professor of geology and geophysics at Yale University.

"The PETM is a stunning example of carbon dioxide-induced global warming and stands in contrast to critics who argue that the Earth temperature is insensitive to increases in carbon dioxide," said Pagani.

"Not only did the Earth warm by at least 9 Fahrenheit (5 Celsius), but it did so during a time when Earth average temperature was already 9 Fahrenheit (5 Celsius) warmer than today."

However, what has not been clear is how much carbon was responsible for the temperature increase and where it came from.

Scientists have speculated that it might have come from massive fires from burning coal and other ancient plant material, or from an increase of methane from the continental shelves that rapidly turned into atmospheric carbon dioxide.

"According to this work, if the PETM was caused by the burning of plant material then climate sensitivity to carbon dioxide is more than 4.5 times per carbon dioxide doubling. And if methane was the culprit, then Earth climate must be extremely sensitive to carbon dioxide increasing, over 10 Fahrenheit (5.56 Celsius) per carbon dioxide doubling," noted Pagani.

This finding contradicts the position held by many climate-change skeptics that the Earth climate is resilient to such carbon dioxide emissions.

"The last time carbon was emitted to the atmosphere on the scale of what we are doing today, there were winners and losers," said Ken Caldeira, a co-author from the Carnegie Institution's Department of Global Ecology.

"There was ecological devastation, but new species rose from the ashes. Our work provides even more incentive to develop the clean energy sources that can provide for economic growth and development without risking the natural world that is our endowment," he said.

As about 90 per cent of the world's ice volume and 70 per cent of its fresh water is on the southernmost continent, any substantial warming could cause a rise in sea levels around the globe.

"It's a bellwether for the planet," Tom Wagner of the US National Science Foundation said in an e-mail interview. "Its ice sheets are the main player in sea level rise; there is already evidence that they are shrinking."

It was easy to imagine melting ice sheets this week around McMurdo Station, the biggest US science centre in Antarctica, with temperatures in the relatively balmy range of -2 C and the 24-hour-a-day spring sunshine causing pools of melted water atop a 3-metre layer of ice around the base.

Much of the sea ice is cracked and the nearby Barne Glacier has had several major collapses onto the sea ice in recent days. Still, heavy tracked vehicles can navigate the ice on designated pathways.

While these are not specifically signs of global warming, Antarctica and the Arctic are key places to look for such signals because even a slight rise in temperature can precipitate melting ice, which would have dramatic effects on living things and land, as well as global climate implications, Wagner said.

Reading ancient rocks

For Ross Powell, an environmental geologist, one way to figure out what the future of climate change might be is to look some 10 million years back in to Antarctica's past.

"We want to go back through time and see the changes that the Antarctic has been through," said Powell, who is based at Northern Illinois University but is working on an international geology project here.

"And one of the key things is finding the warm periods, because we are going into a warming phase now."

Powell is one of the chief scientists on the ANDRILL project shorthand for Antarctic Geologic Drilling Programme where a massive drill burrows down about 260 feet (78 metres) of sea ice, 2,700 feet (810 metres) of ocean water and then into the sediments beneath to see what clues earlier warm periods left behind.

"We need to read the rocks to understand when the ice was there and when it wasn't and what the conditions were in the marine environment associated with the movement of the ice forward and backwards," Powell said in an interview.

So far, ANDRILL researchers have found tantalizing clues about periods when the Antarctic ocean was swarming with marine algae called diatoms, which still exist as one of the most basic links on the planet's food chain.

The glimpse back in time could examine a period in Antarctica's history when levels of the greenhouse gas carbon dioxide were high, but perhaps not as high as scientists predict it will get in the coming decades due to human activity.

If the ice sheets around Antarctica shrink substantially, that would not by itself cause the world's seas to rise, just as an ice cube melting in a glass of water would not cause much of a rise in the level of liquid in the glass.

But the ice sheets perform an important function by slowing down the flow of glacial ice. If the ice sheets go away, many scientists believe that glaciers will flow more swiftly, adding their ice to the oceans, and that could cause sea level rise.