Sunday, December 31, 2006

Climate 2006: Rhetoric Up, Action Down


Climate 2006: Rhetoric up, action down
ANALYSIS
By Richard Black
Environment correspondent, BBC News website

"The gap between what the science tells us is necessary and what the politics is delivering is still significant."

Not the words of a environmental campaigner or a frustrated climate scientist, but the plain assessment from Britain's Environment Secretary David Miliband as the 2006 round of United Nations climate negotiations whimpered to a close.

But environmental campaigners obviously agreed. Some groups even began direct action during the year, something which has traditionally been associated with a completely different power source, nuclear fission.

Coal-fired power stations in the UK, including Europe's biggest, Drax, were blockaded and attempts made to occupy them.

Tens, probably hundreds of thousands marched on a co-ordinated day of action in November.

Musicians and actors joined the fray, as they did on poverty 20 years ago.

Climate change has started to become a popular cause.

Ups and downs

Their argument is simply that the world's political leaders are failing to take the scientific evidence seriously.

As represented most importantly by the Intergovernmental Panel on Climate Change (IPCC), the consensus suggests that global emissions of greenhouse gases need to fall by about 60% on a timescale of a few decades in order to be sure that the most graphic of climate consequences are averted.

Yet at the end of the year, the trend was pointing in the opposite direction.

The rate of emissions growth for carbon dioxide, the most important gas in the man-made greenhouse, is increasing; a decade ago emissions were climbing by less than 1% per year, now the rate is above 2% per year.

"The [greenhouse gas] concentrations in the atmosphere are going up, so it hasn't been a year of success in terms of having an impact on this process," observes Jonathan Lash, president of the World Resources Institute, an environmental think-tank based in Washington DC.

"We have world leaders who say they're committed; but there's a long distance between saying you're committed and making the actual changes in the factories and power plants and automobiles that create the emissions; and that process is still moving very slowly."

Off target

The UN talks in Nairobi ended with no deal on targets for reducing greenhouse gas emissions when the current Kyoto Protocol quotas expire in 2012, and no firm timetable for agreeing such targets.

Whether the UN process can ever deliver further cuts is an open question. In order to get the juggernaut of Kyoto procedures pointing in a new direction by 2012, targets need to be tied up perhaps two years, perhaps three years before that.

The European Union is publicly committed to a new round of targets.

But some member states are a world away from meeting their existing ones; and even as delegates were boarding the planes to Nairobi, many EU governments submitted plans for the second phase of the Emissions Trading Scheme (ETS) which would have raised their emissions, not cut them, in the years running up to 2012.

What of the other processes which have sprung up in the last two years with the declared intention of turning the rising tide of emissions?

The Asia-Pacific Partnership on Clean Development and Climate brings together six countries whose emissions account for roughly half the global total - Australia, China, India, Japan, South Korea and the US - in a pact which aims to reduce emissions by assisting the private sector to create clean technologies and transfer them to developing countries.

It held its first ministerial meeting in Sydney in January. I have rarely seen a room-full of journalists as stunned as the group there were, as US energy secretary Samuel Bodman told us that private companies will solve climate change because the people in charge of them care.

"I believe that the people who run the private sector, who run these companies - they too have children, they too have grandchildren, they too live and breathe in the world, and they would like things dealt with effectively; and that's what this is all about," he said.

The single word "Enron" traversed a hundred brains.

According to an Australian Government report commissioned for the Sydney meeting, the Partnership does not in fact expect to cut global greenhouse gas emissions - it expects them to double over the next 50 years, even if all its projects come to fruition.

There were already suspicions in the NGO community that the Partnership was really about trade, not climate. Since the Sydney meeting we have seen two major deals tied up between members which will see the US export nuclear technology to India, and Australia export uranium to China.

Let us fast forward then to Monterrey in Mexico, and the second ministerial session of the Dialogue on Climate Change, Clean Energy and Sustainable Development, which brings the G8 countries together with major developing nations including Brazil, China, and India.

The conclusions of this potentially very powerful group were that climate change is really serious, we need to do something, but we are not making any firm commitments now.

That might have a familiar feel by now.

Costing the Earth

Two other initiatives burst on to the global stage during 2006; one, a movie from a former politician, the other a weighty report from a leading economist.

Al Gore's An Inconvenient Truth is a masterpiece of communication - wherever you stand on climate science, to make it engaging for an hour and a half is surely some feat. As a tool to change policies, however, its value must be doubtful, as it is largely the converted that will see it.

Sir Nicholas Stern's review of climate change economics should hit a little harder. Certainly Tony Blair thought so, commenting: "It proves tackling climate change is in fact a pro-growth strategy.

"It shows that if we fail to act, the cost of tackling the disruption to people and economies would cost at least 5%, on the worst case scenario as much as 20%, of the world's output. In contrast, the cost of action to halt and reverse climate change would cost just 1%."

As the year ended, Mr Blair's government was, by his own logic, deciding to risk growth by approving expansion plans for major airports.

Sir Nicholas took his review on a tour of world capitals. But even as he breakfasted with officials in Beijing and Delhi, a report from the Asian Development Bank warned that Asia's emissions will triple over the next 25 years.

Boxing clever

The single biggest obstacle to progress in negotiations has been the reluctance of the US to engage and to accept that the international community has any right to restrict its emissions.

But signs emerged that something was changing in Washington with the mid-term elections in November, which returned the Democrats to power in both houses of Congress.

Jonathan Lash believes this is already having an impact on how climate issues are debated.

"A year ago the chairman of the Senate committee that's in charge of environment, Mr Inhofe from Oklahoma, held a climate change hearing and his first witness was a science fiction writer, Michael Crichton, whose theory is that climate change is the biggest hoax ever perpetrated on the world," he recalls.

"Now the chair will be Senator Boxer, who has already committed herself to very strong legislation making mandatory reductions. We'll see the same kind of shift in the House of Representatives; so we're going to see the leadership pushing ahead instead of setting up obstacles."

Below the federal level, states and cities are also pressing ahead with various initiatives, laws and measures on emissions caps, carbon trading, energy efficiency and carbon burial.

None of this is likely to change the US stance in international negotiations, though rumours persist in Washington that President Bush may announce some new measures during his next State of the Union address.

Heated debate

Of course, not everyone is convinced by the scientific arguments of the IPCC or the economic ones of Sir Nicholas Stern.

The diverse community of "climate sceptics" were visible and vocal during 2006, and registered at least one blow for an alternative way of explaining global warming when a Danish research group showed in a laboratory experiment that highly energetic particles could enhance the formation of water droplets in air.

Their theory is that temperature changes result from variations in the intensity of cosmic rays coming from the Sun. Cosmic rays affect the formation of water droplets, which in turn form clouds, which in turn change global temperatures with no help from greenhouse gases.

A number of economists lined up to dispute the Stern Review's methods and conclusions. These voices will surely remain vocal as 2006 turns into 2007.

But shouting loudest of all next year will be the Fourth Assessment Report from the IPCC. It will have been five years in the making, and will present the current consensus on climate science, on impacts and costs, as determined by its committees of experts.

Its headline projections are expected to differ little from those contained in its last report, issued in 2001; rising temperatures, rising sea levels, and major specific impacts such as the irreversible drying out of the Amazon.

Once again we will hear demands from climatologists to keyboard players, from theoretical physicists to thespians, for more action.

Perhaps we will get it. But the omens are not promising.

Richard.Black-INTERNET@bbc.co.uk

Story from BBC NEWS: http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/6197135.stm

Vast ice shelf collapses in the Arctic



http://news.independent.co.uk/environment/article2112609.ece

Vast ice shelf collapses in the Arctic

By Michael McCarthy, Environment Editor

Published: 30 December 2006

A vast ice shelf in the Canadian Arctic has broken up, a further sign of the astonishing rate at which polar ice is now melting because of global warming.

The Ayles ice shelf, more than 40 square miles in extent - over five times the size of central London - has broken clear from the coast of Ellesmere Island, about 500 miles south of the North Pole in the Canadian Arctic, it emerged yesterday.

The broken shelf has formed an ice island, in what a leading scientist described as a "dramatic and disturbing event", citing climate change as the cause.

The news caps a dramatic year of discovery about just how quickly the polar ice is disappearing.

It comes as America's leading climate scientist, James Hansen, warns in today's Independent that the Earth is being turned into "a different planet" because of the continuing increase in man-made emissions of greenhouse gases.

The break-up of the Ayles shelf occurred 16 months ago, in an area so remote it was not at first detected. "This is a dramatic and disturbing event," said Professor Warwick Vincent of Laval University in Quebec City. "It shows that we are losing remarkable features of the Canadian North that have been in place for many thousands of years."Ice shelves float on the sea, but are connected to land (as opposed to ice sheets, which are wholly land-based). In the past five years, several ice shelves along the fringes of the Antarctic peninsula have started to become unstable or break up. The most spectacular was the 2002 collapse of the Larsen B ice shelf, the size of Luxembourg.

Until now, there had not been a similar event among the six major shelves remaining in Canada's Arctic, which are packed with ancient ice that is more than 3,000 years old.

Professor Vincent, who studies Arctic ecosystems, travelled to the newly formed ice island and was amazed at what he saw. "It's like a cruise missile has come down and hit the ice shelf," he said. "Unusually warm temperatures definitely played a major role. It is consistent with climate change." The collapse was picked up by the Canadian Ice Service, which notified Luke Copland, head of the new global ice laboratory at the University of Ottawa. Using US and Canadian satellite images, as well as seismic data - the event registered on earthquake monitors more than 150 miles away - Professor Copland discovered that the ice shelf collapsed in the early afternoon of 13 August 2005. Scientists were surprised at the speed of the event, Professor Copland said - it took less than an hour.

There have already been several disturbing indications this year that the Arctic ice is melting at a much faster rate than expected. In September, two Nasa reports showed a great surge in the disappearance of the winter sea ice over the past two years, with an area the size of Turkey disappearing in 12 months.

City dwellers poised to take over the world


http://news.independent.co.uk/environment/article2114489.ece

City dwellers poised to take over the world

By Geoffrey Lean, Environment Editor

Published: 31 December 2006

Humanity is about to undertake the greatest change of habitat in its entire history. Authoritative international reports to be published over the next months will show that, for the first time, we will soon be a predominantly urban species, with more people living in towns and cities than in the countryside.

Official United Nations figures show that the world's urban population has more than quadrupled over the past 50 years. Almost half of us inhabit towns and cities: within a quarter of a century 60 per cent of us will do so.

London, some 200 years ago, became the first city since ancient Rome to reach a million inhabitants: now, there are more than 200 such cities. About 20 of theseare "megacities" exceeding 10 million, and one, Tokyo, has become a "metacity", with more than 20 million. Reports by Washington's Worldwatch Institute, published next month, and by the UN Population Fund, due in the summer, will describe the imminent transition and grapple with how to cope with the rapidly swelling cities.

The task is all the more difficult and urgent as 95 per cent of the increase is in developing countries, partly through births, but also through migration from the impoverished countryside to swelling slums that are home to a billion people.

10 years to live: Orang-utan faces extinction in the wild


http://news.independent.co.uk/environment/article2081668.ece

10 years to live: Orang-utan faces extinction in the wild

The great ape's habitat is rapidly being destroyed - by the rush to produce an environmentally friendly fuel

By Geoffrey Lean, Environment Editor

Published: 17 December 2006

At least 1,000 orang-utans have been killed in fierce forest fires in Indonesia, hastening the species' headlong rush to extinction within the next decade.

The fires, the worst in a decade and which reached their peak last month, sent a thick pall of smoke across the region, closing airports and forcing drivers to use headlights at noon. Conservationists believe that many were deliberately lit to make room for plantations to grow palm oil - much of it, ironically, to meet the world's growing demand for environmentally friendly fuel.

Their greatest victim is the orang-utan - Asia's only great ape - which is so endangered that many experts believe that it will become extinct in the wild over the next 10 years. Some 50,000 of them, at most, still survive, and about 5,000 are thought to perish every year as the rainforests on which they depend are felled.

Originally some 300,000 of the apes - championed by Sadie Frost in the ITV series Extinct, which ended last night - lived throughout South-east Asia. But now they survive only in isolated pockets on the islands of Borneo and Sumatra. In the past 20 years, 80 per cent of their habitat has been destroyed - and only about 2 per cent of what remains is legally protected in reserves.

"Orang-utans are in catastrophic decline and everything that is being done to protect them is not up to the challenge," said Ian Redmond, chairman of the Ape Alliance, an international coalition of conservation bodies and an adviser to the United Nations Environment Programme. "It is all looking pretty bleak."

The International Fund for Animal Welfare predicts that they will be extinct within 10 years. Other estimates vary either side of that figure. WWF (formerly the World Wildlife Fund) puts it at 20 years, Friends of the Earth at 12, and the Borneo Orang-utan Survival Foundation at just four.

The apes - whose name means "man of the forest" - are one of our closest relatives, sharing about 97 per cent of our DNA. Spending most of their time in the treetops, they mainly live on their own. Mothers keep their babies with them for up to six years, and have a single baby every eight years or so. This leisurely rate of reproduction - the slowest of all the great apes - makes the species particularly vulnerable.

They have long been threatened by the pet trade: the number of the apes per square kilometre in Taiwan's capital, Taipei, is now greater than in their natural rainforest homes. For every one that is sold as a pet, five or six are thought to die. And they are also killed for meat.

But it is the destruction of the rainforest - which used to cover the whole of Borneo - that is much the greatest threat. It has long been cleared for logging and agriculture, but this has accelerated to meet the booming demand for palm oil, used in one in every 10 products on supermarket shelves - and now to feed the growing drive for biofuel, the "green" alternative to petrol and diesel.

The Indonesian government is trying to persuade companies to put their plantations on already deforested and degraded land, but with little success as they can get a double dividend from virgin forests, first by selling the timber, and then from harvesting palm oil cultivated on the cleared ground.

After surviving 20 million years, China's goddess of the river is driven to extinction



http://news.independent.co.uk/environment/article2083841.ece

After surviving 20 million years, China's goddess of the river is driven to extinction

By Clifford Coonan in Beijing

Published: 18 December 2006

For 20 million years, the white-fin dolphin, or baiji, swam China's longest river, the Yangtze. But a few years of breakneck development, overfishing and a massive increase in shipping have reduced sightings of this shy, graceful creature to zero.

A recent expedition failed to spot a single Lipotes vexillifer, and now conservationists fear the almost-blind, long-beaked animal is gone for good, the first big aquatic mammal to become extinct due to human activity.

"We have to accept the fact that the baiji is extinct. It is a tragedy, a loss not only for China, but for the entire world," said the joint leader of the expedition, August Pfluger, an economist who runs the Swiss-based baiji.org, an environmental group dedicated to saving the dolphins.

Scientists say the search for the dolphin will continue, even though the 30-strong team which has plied the length of the Yangtze for the past six weeks failed to sight the cetacean.

Measuring up to 8ft 2in (2.5 metres) in length, the baiji is a relative of other freshwater dolphins in the Mekong, Indus, Ganges and Amazon rivers.

It used to be worshipped as a goddess by the Chinese. According to legend, the baiji is the reincarnation of a princess who refused to marry a man she did not love and was drowned by her father for shaming the family.

When it was listed as one of the most endangered species in the world in 1986, there were still 400 white-fin dolphins alive, but the population dropped alarmingly to fewer than 150 over the past decade. A survey in 1997 listed just 13 sightings, with the last confirmed sighting in 2004. The final baiji in captivity, Qi Qi, died in 2002.

Keen to repeat the success at breeding endangered species that it had with pandas, the Chinese government set up a reserve in a lake in central Hubei province to look after captured baiji, but could not find any of the dolphins to start an artificial propagation programme.

The expedition surveyed the 1,700km river using acoustic equipment to detect the sound of dolphins. There is some slight hope, as some of the sounds gathered have yet to be identified. But as Mr Pfluger says, even if one or two dolphins are left, they are ultimately doomed.

If the dolphin is indeed extinct, it will be the first big aquatic mammal to disappear since hunters killed off the Caribbean monk seal in the 1950s.

Wang Ding, a scientist from the Chinese Academy of Sciences, who led the team of 25 scientists from China, the US, Britain, Japan, Germany and Switzerland, said the search would go on as there might still be some left. "We will try every effort to save them as long as it is not announced to be extinct," he said, adding that the monitoring of hot spots and small-scale searches would continue.

"The expedition only covered the main section of the Yangtze River and the scientists only searched for the dolphins eight hours a day, which means some dolphins might have been missed," he said. By definition, an animal is declared extinct only if it has not been seen in the wild for 50 years, he pointed out.

The white-fin dolphin is top of food chain in the Yangtze and has no natural enemies, except for man. The Yangtze is also China's busiest waterway, and the baiji shared the river with huge ships, tugboats and fishing boats.

Experts describe the white-fin dolphin, which is native to China, as a living fossil as it has not changed in appearance since it first entered the Yangtze from the sea.

China's dolphins are in trouble, facing threats from pollution and economic expansion. The expedition also highlighted the threats to other species. They spotted about 300 members of another endangered species of freshwater mammal, the Yangtze finless porpoise, far fewer than expected.

Scientists said illegal fishing on the river, sometimes using explosives, had wreaked havoc on the dolphin population.

Baiji are also prone to crashing into ship's propellers. Because they have poor eyesight, the dolphins use sound to orient themselves, but their sonar systems are easily disrupted.

The United Nations environment programme has declared the Yangtze a dead zone, saying its water lacks sufficient oxygen to support fish.

"If the Yangtze river can not support the white-fin dolphin at present, maybe it can not support human beings in the future," said Dr Wang. "We must learn a lesson from it."

Friday, December 29, 2006

Global warming could transform Amazon into savanna in 100 years, Brazil researchers say


Global warming could transform Amazon into savanna in 100 years, Brazil researchers say

The Associated Press

Friday, December 29, 2006

RIO DE JANEIRO, Brazil

Global warming could spell the end of the world's largest remaining tropical rain forest, transforming the Amazon into a grassy savanna before end of the century, researchers said Friday.

Jose Antonio Marengo, a meteorologist with Brazil's National Space Research Institute, said that global warming, if left unchecked, will reduce rainfall and raise temperatures substantially in the ecologically rich region.

"We are working with two scenarios: a worst case and a second, more optimistic one," he said in a telephone interview with The Associated Press.

"The worst case scenario sees temperatures rise by 5 to 8 degrees (Celsius) until 2100, while rainfall will decrease between 15 and 20 percent. This setting will transform the Amazon rain forest into a savanna-like landscape," Marengo said.

That scenario supposes no major steps are taken toward halting global warming and that deforestation continues at its current rate, Marengo said.

The more optimistic scenario supposes governments take more aggressive actions to halt global warming. It would still have temperatures rising in the Amazon region by 3 to 5 degrees Celsius and rainfall dropping by 5 to 15 percent, Marengo said.

"If pollution is controlled and deforestation reduced, the temperature would rise by about 5 degrees Celsius in 2100," said Marengo. "Within this scenario, the rain forest will not come to the point of total collapse."

Marengo's finding were part an 800,000 real (US$373,000; €284,000) study that began two years ago and that will continue until 2010. The study, financed by the World Bank and the British government, seeks to project climatic changes that will effect Brazil over the next 100 years. European governments frequently finance environmental and conservation studies about Brazil's Amazon rain forest.

Sprawling over 4.1 million square kilometers (1.6 million square miles), the Amazon covers nearly 60 percent of Brazil. Largely unexplored, it contains one-fifth of the world's fresh water and about 30 percent of the world's plant and animal species — many still undiscovered.

Marengo said he was optimistic that the worst-case scenario could be averted, but he said that would require a major effort by industrialized nations to reduce emissions of so-called greenhouse gases that contribute to global warming.

He said Brazil should do its part by reducing deforestation and burning in the Amazon region.

Destroying trees through burning contributes to global warming, releasing about 370 million tons of greenhouse gases into the atmosphere every year — about 5 percent of the world total — scientists say.

About 20 percent of the rain forest has already been cut down and while the rate of destruction has slowed in recent years, environmentalists say it remains alarmingly high.

Review of the year: Global warming; Our worst fears are exceeded by reality



Review of the year: Global warming

Our worst fears are exceeded by reality

By Steve Connor

Published: 29 December 2006

http://news.independent.co.uk/environment/article2110651.ece

It has been a hot year. The average temperature in Britain for 2006 was higher than at any time since records began in 1659. Globally, it looks set to be the sixth hottest year on record. The signs during the past 12 months have been all around us. Little winter snow in the Alpine ski resorts, continuing droughts in Africa, mountain glaciers melting faster than at any time in the past 5,000 years, disappearing Arctic sea ice, Greenland's ice sheet sliding into the sea. Oh, and a hosepipe ban in southern England.

You could be forgiven for thinking that you've heard it all before. You may think it's time to turn the page and read something else. But you'd be wrong. 2006 will be remembered by climatologists as the year in which the potential scale of global warming came into focus. And the problem can be summarised in one word: feedback.

During the past year, scientific findings emerged that made even the most doom-laden predictions about climate change seem a little on the optimistic side. And at the heart of the issue is the idea of climate feedbacks - when the effects of global warming begin to feed into the causes of global warming. Feedbacks can either make things better, or they can make things worse. The trouble is, everywhere scientists looked in 2006, they encountered feedbacks that will make things worse - a lot worse.

Next year, the UN's Intergovernmental Panel on Climate Change (IPCC) will publish its fourth assessment on the scale of the future problems facing humanity. Its last assessment, published in 2001, had little to say on the subject of climate feedbacks, partly because, at that time, they were such an unknown quantity. This year, scientists came to learn a little more about them, and they didn't like what they learnt.

During the past two decades, the IPCC has tended to regard the Earth's climate as something that will change gradually and smoothly, as carbon dioxide and global temperatures continue their lock-step rise. But there is a growing consensus among many climate scientists that this may be giving a false sense of security. They fear that feedback reactions may begin to kick in and suddenly tip the climate beyond a critical threshold from which it cannot easily recover.

Climate feedbacks could turn the Earth into a very different planet over a dramatically short period of time. It has happened in the past, scientists say, and it could easily happen in the future given the unprecedented scale of the environmental changes caused by man.

There are two types of feedback that can play a role in the future direction of the Earth's climate. The first is a "negative" feedback, which is largely good for us, because it works against things getting worse. The classic example of a negative feedback is the fertilising effect of carbon dioxide. As concentrations rise, then so does the amount of carbon absorbed by the higher growth rate of plants. The result is a negative feedback that tends to check rising levels of carbon dioxide.

A "positive" feedback makes things worse by adding to the existing problem. It brings about a vicious circle, in which a rise in carbon dioxide or global temperatures causes some change in the climate system which, in turn, leads to further rises in carbon dioxide or temperatures.

A classic example of a positive feedback is the melting sea ice of the Arctic. As temperatures rise, the ice floating on the Arctic sea melts, exposing dark ocean where once there was white ice that reflected sunlight, and heat, back into space. The newly revealed dark ocean absorbs more sunlight and heats up, causing more ice to melt, and so reinforcing the positive-feedback cycle.

But even this simple description belies the true complexity of life on Earth. In fact, there is a negative feedback at work as well with Arctic sea ice, which insulates the underlying ocean and keeps it warmer during the cold, dark northern winters. However, on balance, it is the positive feedback that dominates here, as it does in several other instances investigated by scientists in 2006.

"The main concern is that the more we look, the more positive feedbacks we find," says Olivier Boucher, a climate scientist at the Met Office. "That's not the case when it comes to negative feedbacks. There seems to be far fewer of them." The sentiment is echoed by Chris Rapley, the director of the British Antarctic Survey in Cambridge: "When we look at the list of all the feedbacks in the climate, the list of positive feedbacks is worryingly long - a lot longer than the negative feedbacks. To be honest, it's a wonder that the climate has remained so stable."

Let's stick with Arctic sea ice a bit longer before looking at other issues that emerged 2006. In March, Nasa satellites monitored a 28-year record low for winter sea ice. Normally sea ice recovers during the long Arctic winter, but this was the second consecutive year that the ice failed to re-form fully to is previous winter extent.

This meant there was less ice at the start of the northern summer, with the result that last September saw the second monthly minimum for summer sea ice - almost hitting the record minimum set in September 2005.

During the past four or five years, there has been an acceleration in the rate at which sea ice is melting, a change that some scientists put down to a positive feedback. "Our hypothesis is that we've reached the tipping point," says Ron Lindsay of the University of Washington in Seattle. "For sea ice, the positive feedback is that increased summer melt means decreased winter growth and then even more melting the next summer, and so on."

Professor Lindsay likens the positive feedback in the Arctic to a ball that has begun to roll down a slope, gathering momentum and speed as it goes. In order to reverse the direction of movement, the ball has to be pushed back up the slope. But how? "Perhaps a cooling period could reverse the situation," he says. "But with global warming, temperatures are only bound to rise."

While we are in the northern hemisphere, take a look at another positive feedback that scientists investigated in 2006. This is connected to the frozen permafrost of Siberia and northern Canada, which lock up vast stores of carbon in the form of methane, a gas formed by the decomposition of organic matter. For more than 12,000 years, this methane - a greenhouse gas 20 times more potent than carbon dioxide - has been safely stored under the permanently frozen ground. But now the permafrost is melting and the gas is bubbling free into the atmosphere.

Sergei Kirpotin, a botanist at Tomsk State University in Russia, has been studying the extent of the melting permafrost of Western Siberia, the site of the world's biggest frozen peat bog. During the past few years, he has watched lakes getting bigger and bigger as the solid permafrost underneath liquifies.

Normally, patches on white lichen on high Siberian ground reflect the sun's rays and help to keep the ground underneath cold. But as the dark lakes expand, more heat is absorbed and more permafrost melts. "As we predicted in the early 1990s, there's a critical barrier," says Professor Kirpotin. "Once global warming pushes the melting process past that line, it begins to perpetuate itself."

The once-frozen peat bogs of Siberia - bigger than France and Germany combined - began to "boil" furiously in the summer of 2006 as methane bubbled to the surface. Exactly how much is being released into the atmosphere is unknown, although some estimates put it as high as 100,000 tons a day - which means a warming effect greater than America's man-made emissions of carbon dioxide.

But Katey Walter of the University of Alaska believes even this could be seriously underestimated. In a study published in Nature in September, Walter and her colleagues calculated that the level of methane emissions from Siberia could be anywhere between 10 per cent and 63 per cent higher than anyone had hitherto suspected. "We have shown that the North Siberian lakes are a significantly larger source of atmospheric methane than previously recognised," she says.

So the message is clear: frozen peat bogs that turn into heat-absorbing lakes release methane, which means a stronger greenhouse effect and higher temperatures, leading to more permafrost melting. The cycle was clearly documented in 2006 but just how strong this positive feedback turns out to be has yet to be fully determined.

Another study in 2006 looked at perhaps the most important climate feedback there is. Yet it went unreported - so listen up. The Earth has been a very accommodating planet. During the past 200 years, it has absorbed more than half of all man-made emissions of carbon dioxide through natural carbon "sinks", mostly in the ocean but also on land. The rest of the emissions have been left in the air to aggravate the Earth's natural greenhouse effect, so raising global average temperatures.

But what if something were to interfere with these very useful carbon "sinks"? Can we forever rely on them to remain sinks, or could they turn into dangerous sources of atmospheric carbon? A huge international team of climatologists asked these questions in a little-known study published in the July issue of the Journal of Climate. The conclusion makes depressing reading.

The scientists investigated what would happen if they tinkered with 11 of the world's biggest computer models of the complex climate-carbon cycle. They wanted to simulate what would happen to the carbon sinks on the land and the ocean for each model as the world gets warmer. All the models agreed that as the world heated up, the ability of the land and the oceans to keep on absorbing carbon as efficiently as they have in the past 200 years gets appreciably worse.

In other words, we cannot rely on planet Earth to be so accommodating in terms of mopping up half of our carbon pollution. But could something even worse happen? Could these carbon sinks turn into carbon sources? The answer is yes. Many models suggest that the terrestrial biosphere could become a net carbon producer by the mid 21st century. Signs are that it is already happening in some parts of the world.

Guy Kirk of the National Soil Resources Institute at Cranfield University found that the soil of Britain is releasing more carbon dioxide into the atmosphere than a quarter of a century ago because increasing temperatures are speeding up the rate of organic decay. "It's a feedback loop," says Professor Kirk. "The warmer it gets, the faster it is happening." In fact, he estimates that since 1978, Britain's soil has released on average an extra 13 million tons of carbon dioxide a year, which is more than the 12.7 million tons a year Britain saved by cleaning up its industrial emissions.

The outlook does not look any better out at sea. The important carbon sinks of the ocean are also suffering from feedback. As more carbon dioxide dissolves in seawater to form carbonic acid, the acidity of the ocean increases - the rate is 100 times faster than at any time for millions of years.

There is a physical feedback - it is just harder for more carbon dioxide to dissolve in acid water - as well as a biological feedback. Tiny organisms called coccolithophores use dissolved carbon to make their shells, but acidic seas make this more difficult. This blocks an important biological pump that pushes carbon to a long-term store on the seabed - which is what happens when billions of tiny shells sink to the depths as coccolithophores die.

Yet another ocean feedback was monitored in 2006, this time involving phytoplankton, the tiny microscopic plants of the sea that form the basis of the entire marine food chain. Nasa satellites showed earlier this month that phytoplankton - which absorb carbon dioxide - are finding it harder to live in the more stratified layers of the warmer ocean, which restrict the mixing of vital nutrients. Since 2000, when the sea surface temperatures began to rise more noticeably, the photosynthetic productivity of phytoplankton have decreased in some ocean regions by 30 per cent.

"As climate warms, phytoplankton production goes down, but this also means that carbon dioxide uptake by ocean plants will decrease," says Michael Behrenfeld of Oregon State University. "That would allow carbon dioxide to accumulate more rapidly in the atmosphere, making the problem worse." Some climate scientists believe that the risk of dangerous feedbacks tipping the Earth's climate system beyond a threshold is so great that there should be wider recognition of what they term "abrupt changes". The point is, they say, it has happened repeatedly in the past. It happened 55 million years ago when a trillion tons of methane were suddenly and mysteriously released from frozen stores on the seabed, causing global temperatures to soar 10C, and a mass extinction of species.

It happened 14,500 years ago when ice sheets catastrophically collapsed into the ocean causing sea levels to rise by 20 metres in just 400 years. And it happened 6,500 years ago when the Sahara was suddenly turned from lush vegetation to dry desert.

Scientists say that what is happening now to the planet in terms of carbon dioxide levels and global temperatures is just as abrupt as anything that has occurred in the past. "What we are doing now to the Earth is unprecedented," says Professor Rapley of the British Antarctic Survey, "so we cannot rule out the possibility that we are doing something that will create a strong positive feedback, which will push the Earth into a domain where things will happen that have never happened before."

It is a sobering thought as 2006 draws to a close, and one that must be in the minds of all the IPCC scientists preparing next year's Fourth Assessment Report on climate change.

A VISION OF THE FUTURE

The single most momentous environmental image of 2006 was a holiday snap. Of sorts. It showed typical European package tourists on a nice sandy beach in Tenerife. Until a few minutes before the picture was taken, on August 3 on Tejita beach in Granadilla, it had been a day of utter normality for these tourists. Then something very different erupted on to the scene.

From the sea came a boat. Out of it fell pitiful figures - exhausted, terrified, dehydrated, starving. They were African migrants who, out of desperation, had risked the long voyage from the African coast to the Canaries; for the Canaries are part of Europe, a place of hope and opportunity. What did the tourists do? They did the decent thing. They rushed to the aid of fellow men and women.

But will they offer such a welcome when the boat people are not just a boatload, but a whole country- or region-load? For that is coming. As climate change takes hold this century, agriculture may fail in some of the poorest and most densely populated parts of the world.

Sir Crispin Tickell, Britain's former Ambassador to the UN, who is one of the most far-sighted of environmental commentators, pointed out as long ago as 1990 that global warming is likely to create environmental refugees in the hundreds of millions. We have paid little attention to his warning.

But if you look at the picture taken on Tejita beach, you can see something even more dramatic than the fact that the ordinary European holidaymaker has a lifestyle most Africans can only dream of. You can see the future, starting to happen.

Michael McCarthy

Global warming starving fish species to death



http://www.zeenews.com/znnew/articles.asp?aid=344612&ssid=26&sid=ENV


Sydney, Dec 28: Fish species in the Great Barrier Reef are starving to death because climate change is killing off their food source, an environmental study conducted over five years by the ARC Centre of Excellence for Coral Reef Studies (CoECRS) has revealed.

The study found that rising sea temperatures had bleached more than 30 per cent of the world's coral reefs, as a result of which, smaller fish which normally feeds on live coral are dying off.

This could throw the fish food chain out of balance, and consequently hinder local fishing and tourism operations, the study said.

According to CoECRS senior researcher Morgan Pratchett, this is only a glimpse of the larger to coral reef due to rising temperature.

If sea temperatures continue their warming patters, the coral damage could double by 2030, he said.

“The starving fish fail to breed and fail to migrate to thriving reefs. Fish can be very territorial and it may be hard for refugee fish, which have lost their reef, to relocate elsewhere because the locals will try to keep them out," the Sydney Morning Herald quoted him as saying.

“Bleaching causes the corals to shed their natural bacteria and die. Ours and other studies indicate that when coral bleaching occurs, affecting up to 10 per cent of the reef, it affects the abundance of nearly two-thirds of the fish species on that reef. As the damage rises to 20 per cent and above, there is a marked decline in the richness of fish species on the reef and the losses can last for years," he said.

He however, said coral-feeding fish would return if the corals recovered.

Thursday, December 28, 2006

Bush embraces the endangered polar bear - and accepts the dangers of global warming


Bush embraces the endangered polar bear - and accepts the dangers of global warming

By Andrew Buncombe in Washington

Published: 28 December 2006

http://news.independent.co.uk/environment/article2108212.ece

In a landmark decision, the Bush administration has concluded that global warming is endangering the existence of the polar bear - an admission that could force the US government to act to curb the emission of greenhouse gases.

In a sharp reversal from its previous position, the Department of the Interior (DOI) has decided one of nature's most iconic creatures should be listed as "threatened" under the Endangered Species Act (ESA) because "the polar bears' habitat may literally be melting".

The decision potentially has huge implications that go beyond the survival of the polar bear: the ESA of 1973 not only requires the government to come up with a recovery plan for the bears but also prevents it from " enacting, funding, or authorising [actions which] adversely modify the animal's critical habitats".

Interior Secretary Dirk Kempthorne said that while the administration recognised the role of greenhouse gases in climate change, "the proposal to list the species as threatened cites the threat of receding sea ice [but] does not include a scientific analysis of the causes of climate change. That analysis is beyond the scope of the ESA review process".

Asked directly whether the government was not now required to act to curb emissions, he replied: "We don't have the expertise to make this analysis." He also said studies had concluded oil and gas exploration in the Arctic was not a threat to the bears - a claim contested by some enviromentalists.

But last night campaigners insisted the decision provided the bears with new, legally enforceable protection and opened the way for widespread legal action to force the Bush administration to limit emission of carbon dioxide and other warming gases.

"I think this is a watershed decision," said Kassie Siegel of the Centre for Biological Diversity, one of three groups that petitioned the DOI to act. "Even the Bush administration can no longer deny the science... There definitely is a new source of liability. For large emitters of greenhouse gases, if they do not consider the impact of those emissions on polar bears there is a provision for us and others to sue."

Andrew Wetzler of the Natural Resources Defence Council (NRDC), added: " Global warming is the single biggest threat to polar bears survival, and this will require the government to address the impacts on the polar bear." It has long been known that global warming was threatening the existence of polar bears, the world's largest bear whose total population is estimated at 22,000, located in Canada, the US, Greenland, Russia and Norway. The Swiss-based World Conservation Union has estimated the bear's numbers will plunge by 30 per cent over the next 45 years as a result of melting sea ice. In Canada's Hudson Bay area, numbers fell by an estimated 22 per cent per cent between 1997 and 2004.

Last year the Independent on Sunday reported anecdotal testimony from indigenous Inuit from Alaska and Canada who told how thinning ice and longer summers were resulting in fewer polar bears - some of which were drowning at sea as they were trapped on melting floes.

John Keogak, 47, an Inuvialuit hunter from Canada's North-West Territories, said: "The polar bear is part of our culture. They use the ice as a hunting ground for the seals. If there is no ice there is no way the bears will be able to catch the seals... here is an earlier break-up of ice, a later freeze-up. Now it's more rapid. Something is happening."

Science has supported such claims, revealing how in the Arctic, where temperatures are rising much more than elsewhere in the world, ice is decreasing in size every year. Earlier this month researchers from the Colorado-based National Centre for Atmospheric Research suggested summer ice may disappear entirely by 2040 - 40 years earlier than previous estimates.

The report's author Marika Holland, said: "We have already witnessed major losses in sea ice, but our research suggests that the decrease over the next few decades could be far more dramatic. As the ice retreats, the ocean transports more heat to the Arctic and the open water absorbs more sunlight, further accelerating the rate of warming."

Though the US is responsible for 25 per cent of the world's carbon emissions, the Bush administration has resolutely refused to enforce limits or else enter legally-binding international agreements to tackle climate change, saying such a move would damage the economy. Last month lawyers from the Environmental Protection Agency (EPA) argued before the Supreme Court that the science on climate change was uncertain. They further argued that the agency was not empowered to act to curb emissions.

Kert Davies, a climate campaigner with Greenpeace, said: "The United States has failed to lead the world in tackling global warming. With under five percent of the world's people, we generate more than 20 percent of the global warming pollution. We must start cutting greenhouse gas emissions or the polar bear will be pushed to the brink of extinction within our lifetime. "

Under the terms of the ESA, the public has 90 days to comment on the DOI proposal. "Our goal ultimately is to combine the best science available with the power of working hand-in-hand with states, tribes, foreign countries, industry, and other partners to minimise the threats to polar bears and conserve this great icon of the Arctic for future generations," said Mr Kempthorne.

Saturday, December 23, 2006

Bears have stopped hibernating


Climate Change vs Mother Nature: Scientists reveal that bears have stopped hibernating

Published: 21 December 2006

http://news.independent.co.uk/environment/article2091875.ece

Bears have stopped hibernating in the mountains of northern Spain, scientists revealed yesterday, in what may be one of the strongest signals yet of how much climate change is affecting the natural world.

In a December in which bumblebees, butterflies and even swallows have been on the wing in Britain, European brown bears have been lumbering through the forests of Spain's Cantabrian mountains, when normally they would already be in their long, annual sleep.

Bears are supposed to slumber throughout the winter, slowing their body rhythms to a minimum and drawing on stored resources, because frozen weather makes food too scarce to find. The barely breathing creatures can lose up to 40 per cent of their body weight before warmer springtime weather rouses them back to life.

But many of the 130 bears in Spain's northern cordillera - which have a slightly different genetic identity from bear populations elsewhere in the world - have remained active throughout recent winters, naturalists from Spain's Brown Bear Foundation (La Fundación Oso Pardo - FOP) said yesterday.

The change is affecting female bears with young cubs, which now find there are enough nuts, acorns, chestnuts and berries on thebleak mountainsides to make winter food-gathering sorties "energetically worthwhile", scientists at the foundation, based in Santander, the Cantabrian capital, told El Pais newspaper.

"If the winter is mild, the female bears find it is energetically worthwhile to make the effort to stay awake and hunt for food," said Guillermo Palomero, the FOP's president and the co-ordinator of a national plan for bear conservation. This changed behaviour, he said, was probably a result of milder winters. "The high Cantabrian peaks freeze all winter, but our teams of observers have been able to follow the perfect outlines of tracks from a group of bears," he said.

The FOP is financed by Spain's Environment Ministry and the autonomous regions of Cantabria, Asturias, Galicia and Castilla-Leon, where the bears roam in search of mates. Indications of winter bear activity have been detected for some time, but only in the past three years have such signs been observed "with absolute certainty", according to the scientists.

"Mother bears with cubs make the effort to seek out nuts and berries if these have been plentiful, and snow is scarce," Mr Palomero said, adding that even for those bears - mostly mature males - who do close down for the winter, "their hibernation period gets shorter every year".

The behaviour change suggests that global warming is responsible for this revolution in ursine behaviour, says Juan Carlos García Cordón, a professor of geography at Santander's Cantabria University, and a climatology specialist.

"Meteorological data in the high mountains is scarce, but it seems that the warming is more noticeable in the valleys where cold air accumulates," Dr García Cordón said. "There is a decline in snowfall, and in the time snow remains on the ground, which makes access to food easier. As autumn comes later, and spring comes earlier, bears have an extra month to forage for food.

"We cannot prove that non-hibernation is caused by global warming, but everything points in that direction."

Spanish meteorologists predict that this year is likely to be the warmest year on record in Spain, just as it is likely to be the warmest year recorded in Britain (where temperature records go back to 1659). Globally, 2006 is likely to be the sixth warmest year in a record going back the mid-19th century.

Mark Wright, the science adviser to the World Wide Fund for Nature (WWF) in the UK, said that bears giving up hibernation was "what we would expect" with climate change.

"It does not in itself prove global warming, but it is certainly consistent with predictions of it," he said. "What is particularly interesting about this is that hitherto the warming has seemed to be happening fastest at the poles and at high latitudes, and now we're getting examples of it happening further south, and heading towards the equator.

"I think it's an indication of what's to come. It shows climate change is not a natural phenomenon but something that is affecting not only on the weather, but impacting on the natural world in ways we're only now beginning to understand."

The European brown bear, with its characteristic pelt that ranges from dark brown through shades of grey to pale gold, has black paws and a tawny face. It has poor vision, although it sees in colour and at night, and if threatened rears on its hind legs to get a better view. It can live for up to 30 years. It has acute hearing, and an especially fine sense of smell that enables it to detect food from a long distance. It is carnivorous, but has a multifunctional dental system with powerful canines and grinding molars perfectly adapted to an omnivorous diet.

The animals would normally begin hibernation between October and December, and resume activity between March and May.

The Cantabrian version of the brown bear, a protected species, was once as endangered as the Iberian lynx or the imperial eagle still are in Spain, but is now recovering in numbers. Between 70 and 90 bears roamed Spain's northern mountains in the early 1990s; now 130 live there.

Other seasonal freaks

* The osprey found in the lochs and glens of the Scottish Highlands in the summer months, usually migrate to west Africa to avoid the freeze. This winter, osprey have been spotted in Suffolk and Devon. Swallows, which also normally migrate to Africa for the winter have been also seen across England this winter.

* The red admiral butterfly, below, which hibernates in winter, has been spotted in gardens this month, as has the common darter dragonfly, usually seen between mid-June and October, which has been seen in Cheshire, Norfolk and Hampshire.

* The smew, a diving duck, flies west to the UK for winter from Russia and Scandinavia. This year, though, they have been mainly absent from the lakes and reservoirs between The Wash and the Severn.

* Evergreen ivy and ox-eye daisies are still blooming and some oak trees, which are usually bare by November, were still in leaf on Christmas Day last year.

* The buff-tailed bumblebee is usually first seen in spring. Worker bees die out by the first frost, while fertilised queen bees survive underground between March and September. This December, bees have been seen in Nottingham and York.

* Primroses and daffodils are already flowering at the National Botanic Garden of Wales, in Carmarthenshire. 'Early Sensation' daffodils usually flower from January until February. Horticulturalists put it down to the warm weather.

* Scientists in the Netherlands reported more than 240 wild plants flowering in the first 15 days of December, along with more than 200 cultivated species. Examples included cow parsley and sweet violets. Just two per cent of these plants normally flower in winter, while 27 per cent end their main flowering period in autumn and 56 per cent before October.

Geneviève Roberts

Tuesday, December 19, 2006

Methane Escaping Five Times Faster Than Previously Thought


Methane Escaping Five Times Faster Than Previously Thought

Study Says Methane a New Climate Threat

The Associated Press, Sept,7, 2006


WASHINGTON  Global warming gases trapped in the soil are bubbling out of the thawing permafrost in amounts far higher than previously thought and may trigger what researchers warn is a climate time bomb.

Methane -- a greenhouse gas 23 times more powerful than carbon dioxide -- is being released from the permafrost at a rate five times faster than thought, according to a study being published Thursday in the journal Nature. The findings are based on new, more accurate measuring techniques.

"The effects can be huge," said lead author Katey Walter of the University of Alaska at Fairbanks said. "It's coming out a lot and there's a lot more to come out."

Scientists worry about a global warming vicious cycle that was not part of their already gloomy climate forecast: Warming already under way thaws permafrost, soil that has been continuously frozen for thousands of years. Thawed permafrost releases methane and carbon dioxide. Those gases reach the atmosphere and help trap heat on Earth in the greenhouse effect. The trapped heat thaws more permafrost and so on.

"The higher the temperature gets, the more permafrost we melt, the more tendency it is to become a more vicious cycle," said Chris Field, director of global ecology at the Carnegie Institution of Washington, who was not part of the study. "That's the thing that is scary about this whole thing. There are lots of mechanisms that tend to be self-perpetuating and relatively few that tend to shut it off."

Some scientists say this vicious cycle is already under way, but others disagree.

Most of the methane-releasing permafrost is in Siberia. Another study earlier this summer in the journal Science found that the amount of carbon trapped in this type of permafrost -- called yedoma -- is much more prevalent than originally thought and may be 100 times the amount of carbon released into the air each year by the burning of fossil fuels.

It won't all come out at once or even over several decades, but if temperatures increase, then the methane and carbon dioxide will escape the soil, scientists say.

The permafrost issue has caused a quiet buzz of concern among climate scientists and geologists. Specialists in Arctic climate are coming up with research plans to study the permafrost effect, which is not well understood or observed, said Robert Corell, chairman of the Arctic Climate Impact Assessment, a study group of 300 scientists.

"It's kind of like a slow-motion time bomb," said Ted Schuur, a professor of ecosystem ecology at the University of Florida and co-author of the study in Science.

Most of the yedoma is in little-studied areas of northern and eastern Siberia. What makes that permafrost special is that much of it lies under lakes; the carbon below gets released as methane. Carbon beneath dry permafrost is released as carbon dioxide.

Using special underwater bubble traps, Walter and her colleagues found giant hot spots of bubbling methane that were never measured before because they were hard to reach.

"I don't think it can be easily stopped; we'd really have to have major cooling for it to stop," Walter said.

Scientists aren't quite sure whether methane or carbon dioxide is worse. Methane is far more powerful in trapping heat, but only lasts about a decade before it dissipates into carbon dioxide and other chemicals. Carbon dioxide traps heat for about a century.

"The bottom line is it's better if it stays frozen in the ground," Schuur said. "But we're getting to the point where it's going more and more into the atmosphere."

Vladimir Romanovsky, geophysics professor at the University of Alaska at Fairbanks, said he thinks the big methane or carbon dioxide release hasn't started yet, but it's coming. In Alaska and Canada -- which have far less permafrost than Siberia -- it's closer to happening, he said. Already, the Alaskan permafrost is reaching the thawing point in many areas.

Source: Associated Press

Drought Seen Overtaking Half the Planet By 2100




Drought Seen Overtaking Half the Planet By 2100

The century of drought

One third of the planet will be desert by the year 2100, say climate experts in the most dire warning yet of the effects of global warming

The Independent (U.K.), Oct. 4, 2006

http://www.heatisonline.org/contentserver/objecthandlers/index.cfm?id=6083&method=full

Drought threatening the lives of millions will spread across half the land surface of the Earth in the coming century because of global warming, according to new predictions from Britain's leading climate scientists.

Extreme drought, in which agriculture is in effect impossible, will affect about a third of the planet, according to the study from the Met Office's Hadley Centre for Climate Prediction and Research.

It is one of the most dire forecasts so far of the potential effects of rising temperatures around the world - yet it may be an underestimation, the scientists involved said yesterday.

The findings, released at the Climate Clinic at the Conservative Party conference in Bournemouth, drew astonished and dismayed reactions from aid agencies and development specialists, who fear that the poor of developing countries will be worst hit.

"This is genuinely terrifying," said Andrew Pendleton of Christian Aid. "It is a death sentence for many millions of people. It will mean migration off the land at levels we have not seen before, and at levels poor countries cannot cope with."

One of Britain's leading experts on the effects of climate change on the developing countries, Andrew Simms from the New Economics Foundation, said: "There's almost no aspect of life in the developing countries that these predictions don't undermine - the ability to grow food, the ability to have a safe sanitation system, the availability of water. For hundreds of millions of people for whom getting through the day is already a struggle, this is going to push them over the precipice."

The findings represent the first time that the threat of increased drought from climate change has been quantified with a supercomputer climate model such as the one operated by the Hadley Centre.

Their impact is likely to even greater because the findings may be an underestimate. The study did not include potential effects on drought from global-warming-induced changes to the Earth's carbon cycle.

In one unpublished Met Office study, when the carbon cycle effects are included, future drought is even worse.

The results are regarded as most valid at the global level, but the clear implication is that the parts of the world already stricken by drought, such as Africa, will be the places where the projected increase will have the most severe effects.

The study, by Eleanor Burke and two Hadley Centre colleagues, models how a measure of drought known as the Palmer Drought Severity Index (PDSI) is likely to increase globally during the coming century with predicted changes in rainfall and heat around the world because of climate change. It shows the PDSI figure for moderate drought, currently at 25 per cent of the Earth's surface, rising to 50 per cent by 2100, the figure for severe drought, currently at about 8 per cent, rising to 40 cent, and the figure for extreme drought, currently 3 per cent, rising to 30 per cent.

Senior Met Office scientists are sensitive about the study, funded by the Department for Environment, Food and Rural Affairs, stressing it contains uncertainties: there is only one climate model involved, one future scenario for emissions of greenhouse gases (a moderate-to-high one) and one drought index. Nevertheless, the result is "significant", according to Vicky Pope, the head of the Hadley Centre's climate programme. Further work would now be taking place to try to assess the potential risk of different levels of drought in different places, she said.

The full study - Modelling the Recent Evolution of Global Drought and Projections for the 21st Century with the Hadley Centre Climate Model - will be published later this month in The Journal of Hydrometeorology .

It will be widely publicised by the British Government at the negotiations in Nairobi in November on a successor to the Kyoto climate treaty. But a preview of it was given by Dr Burke in a presentation to the Climate Clinic, which was formed by environmental groups, with The Independent as media partner, to press politicians for tougher action on climate change. The Climate Clinic has been in operation at all the party conferences.

While the study will be seen as a cause for great concern, it is the figure for the increase in extreme drought that some observers find most frightening.

"We're talking about 30 per cent of the world's land surface becoming essentially uninhabitable in terms of agricultural production in the space of a few decades," Mark Lynas, the author of High Tide, the first major account of the visible effects of global warming around the world, said. "These are parts of the world where hundreds of millions of people will no longer be able to feed themselves."

Mr Pendleton said: "This means you're talking about any form of development going straight out of the window. The vast majority of poor people in the developing world are small-scale farmers who... rely on rain."

A glimpse of what lies ahead

The sun beats down across northern Kenya's Rift Valley, turning brown what was once green. Farmers and nomadic herders are waiting with bated breath for the arrival of the "short" rains - a few weeks of intense rainfall that will ensure their crops grow and their cattle can eat.

The short rains are due in the next month. Last year they never came; large swaths of the Horn of Africa stayed brown. From Ethiopia and Eritrea, through Somalia and down into Tanzania, 11 million people were at risk of hunger.

This devastating image of a drought-ravaged region offers a glimpse of what lies ahead for large parts of the planet as global warming takes hold.

In Kenya, the animals died first. The nomadic herders' one source of sustenance and income - their cattle - perished with nothing to eat and nothing to drink. Bleached skeletons of cows and goats littered the barren landscape.

The number of food emergencies in Africa each year has almost tripled since the 1980s. Across sub-Saharan Africa, one in three people is under-nourished. Poor governance has played a part.

Pastoralist communities suffer most, rather than farmers and urban dwellers. Nomadic herders will walk for weeks to find a water hole or riverbed. As resources dwindle, fighting between tribes over scarce resources becomes common.

One of the most critical issues is under-investment in pastoralist areas. Here, roads are rare, schools and hospitals almost non-existent.

Nomadic herders in Turkana, northern Kenya, who saw their cattle die last year, are making adjustments to their way of life. When charities offerednew cattle, they said no. Instead, they asked for donkeys and camels - animals more likely to survive hard times.

Pastoralists have little other than their animals to rely on. But projects which provide them with money to buy food elsewhere have proved effective, in the short term at least.

Steve Bloomfield

Drought threatening the lives of millions will spread across half the land surface of the Earth in the coming century because of global warming, according to new predictions from Britain's leading climate scientists.

Extreme drought, in which agriculture is in effect impossible, will affect about a third of the planet, according to the study from the Met Office's Hadley Centre for Climate Prediction and Research.

It is one of the most dire forecasts so far of the potential effects of rising temperatures around the world - yet it may be an underestimation, the scientists involved said yesterday.

The findings, released at the Climate Clinic at the Conservative Party conference in Bournemouth, drew astonished and dismayed reactions from aid agencies and development specialists, who fear that the poor of developing countries will be worst hit.

"This is genuinely terrifying," said Andrew Pendleton of Christian Aid. "It is a death sentence for many millions of people. It will mean migration off the land at levels we have not seen before, and at levels poor countries cannot cope with."

One of Britain's leading experts on the effects of climate change on the developing countries, Andrew Simms from the New Economics Foundation, said: "There's almost no aspect of life in the developing countries that these predictions don't undermine - the ability to grow food, the ability to have a safe sanitation system, the availability of water. For hundreds of millions of people for whom getting through the day is already a struggle, this is going to push them over the precipice."

The findings represent the first time that the threat of increased drought from climate change has been quantified with a supercomputer climate model such as the one operated by the Hadley Centre.

Their impact is likely to even greater because the findings may be an underestimate. The study did not include potential effects on drought from global-warming-induced changes to the Earth's carbon cycle.

In one unpublished Met Office study, when the carbon cycle effects are included, future drought is even worse.

The results are regarded as most valid at the global level, but the clear implication is that the parts of the world already stricken by drought, such as Africa, will be the places where the projected increase will have the most severe effects.

The study, by Eleanor Burke and two Hadley Centre colleagues, models how a measure of drought known as the Palmer Drought Severity Index (PDSI) is likely to increase globally during the coming century with predicted changes in rainfall and heat around the world because of climate change. It shows the PDSI figure for moderate drought, currently at 25 per cent of the Earth's surface, rising to 50 per cent by 2100, the figure for severe drought, currently at about 8 per cent, rising to 40 cent, and the figure for extreme drought, currently 3 per cent, rising to 30 per cent.

Senior Met Office scientists are sensitive about the study, funded by the Department for Environment, Food and Rural Affairs, stressing it contains uncertainties: there is only one climate model involved, one future scenario for emissions of greenhouse gases (a moderate-to-high one) and one drought index. Nevertheless, the result is "significant", according to Vicky Pope, the head of the Hadley Centre's climate programme. Further work would now be taking place to try to assess the potential risk of different levels of drought in different places, she said.

The full study - Modelling the Recent Evolution of Global Drought and Projections for the 21st Century with the Hadley Centre Climate Model - will be published later this month in The Journal of Hydrometeorology .

It will be widely publicised by the British Government at the negotiations in Nairobi in November on a successor to the Kyoto climate treaty. But a preview of it was given by Dr Burke in a presentation to the Climate Clinic, which was formed by environmental groups, with The Independent as media partner, to press politicians for tougher action on climate change. The Climate Clinic has been in operation at all the party conferences.

While the study will be seen as a cause for great concern, it is the figure for the increase in extreme drought that some observers find most frightening.

"We're talking about 30 per cent of the world's land surface becoming essentially uninhabitable in terms of agricultural production in the space of a few decades," Mark Lynas, the author of High Tide, the first major account of the visible effects of global warming around the world, said. "These are parts of the world where hundreds of millions of people will no longer be able to feed themselves."

Mr Pendleton said: "This means you're talking about any form of development going straight out of the window. The vast majority of poor people in the developing world are small-scale farmers who... rely on rain."

A glimpse of what lies ahead

The sun beats down across northern Kenya's Rift Valley, turning brown what was once green. Farmers and nomadic herders are waiting with bated breath for the arrival of the "short" rains - a few weeks of intense rainfall that will ensure their crops grow and their cattle can eat.

The short rains are due in the next month. Last year they never came; large swaths of the Horn of Africa stayed brown. From Ethiopia and Eritrea, through Somalia and down into Tanzania, 11 million people were at risk of hunger.

This devastating image of a drought-ravaged region offers a glimpse of what lies ahead for large parts of the planet as global warming takes hold.

In Kenya, the animals died first. The nomadic herders' one source of sustenance and income - their cattle - perished with nothing to eat and nothing to drink. Bleached skeletons of cows and goats littered the barren landscape.

The number of food emergencies in Africa each year has almost tripled since the 1980s. Across sub-Saharan Africa, one in three people is under-nourished. Poor governance has played a part.

Pastoralist communities suffer most, rather than farmers and urban dwellers. Nomadic herders will walk for weeks to find a water hole or riverbed. As resources dwindle, fighting between tribes over scarce resources becomes common.

One of the most critical issues is under-investment in pastoralist areas. Here, roads are rare, schools and hospitals almost non-existent.

Nomadic herders in Turkana, northern Kenya, who saw their cattle die last year, are making adjustments to their way of life. When charities offerednew cattle, they said no. Instead, they asked for donkeys and camels - animals more likely to survive hard times.

Pastoralists have little other than their animals to rely on. But projects which provide them with money to buy food elsewhere have proved effective, in the short term at least.