The United States is the world's largest consumer of energy, but has refused to sign up to the Kyoto pact aimed at reducing emissions of gases that scientists say are to blame for heating up the Earth.

Many environmentalists had expected the first big population shift to come somewhere like the Tuamotu islands in French Polynesia, the world's largest chain of atolls which rise barely metres (feet) from the Pacific.

Rising sea levels are part of the problem afflicting low-lying places but, experts argue, so are tropical storms that are mounting in ferocity because of warmer ocean temperatures.

Brown said many thousands of people who evacuated last year as Katrina slammed into New Orleans and other populated areas on the Mississippi and Louisiana coasts had no intention of returning.

"We estimate that at least 250,000 of them have established homes elsewhere and will not return," he said.

"They no longer want to face the personal trauma and financial risks associated with rising seas and more destructive storms. These evacuees are now climate refugees."

Many businesses have also deserted the coastal towns left ravaged by Katrina as insurance and other costs soar, the study said.

"As rising seas and more powerful hurricanes translate into higher insurance costs in these coastal communities, people are retreating inland," Brown said.

"And just as companies migrate to regions with lower wages, they also migrate to regions with lower insurance costs."

The study also warned: "The experience with more destructive storms in recent years is only the beginning."

The institute said that since 1970, the Earth's average temperature has risen by one degree Fahrenheit, but by 2100 it could rise by up to 10 degrees Fahrenheit (six degrees Celsius).

Rising temperatures could melt glaciers and polar ice caps, raising sea levels and displacing coastal residents worldwide.

"The flow of climate refugees to date numbers in the thousands, but if we do not quickly reduce CO2 (carbon dioxide) emissions, it could one day number in the millions," Brown said.

The institute's study classed "climate refugees" as part of a larger group of people who have been forced from their homes by man-made environmental change such as overgrazing.

"Overgrazing destroys the vegetation which leads then to local sandstorms ... we are looking at growing flows of environmental refugees in Africa, for example in Nigeria, Senegal, Mauritania or Kenya," Brown told reporters.

Millions of people in northern and western China have abandoned their villages as the land turns semi-arid because of overgrazing, the study said.

China is also the second biggest greenhouse-gas polluter after the United States thanks to the voracious rise in coal, gas and oil consumption to power its economic growth.

The booming port city of Shanghai could be at risk of flooding from more ferocious typhoons linked to global warming as it is only a metre (three feet) above sea level, Brown said.

However, other scientists blame a decades-long natural variation in ocean temperature, called the Atlantic Multidecadal Oscillation, or AMO, for the rising SST trend.

Both camps agree that rising SSTs are contributing to increasing hurricane strength, but until now, the connection between air temperature and SST was unclear. Do rising atmospheric temperatures cause sea surface temperatures to rise? Or is it the other way around?

Now, James Elsner, director of the Hurricane Center at Florida State University, says he has broken the deadlock using a statistical test that determines causality. His conclusion: that a warming atmosphere is raising sea surface temperatures, causing hurricanes to become stronger.

Elsner's finding is detailed in the current issue of the journal Geophysical Letters.

X predicts Y, but not vice versa

Elsner looked at the connection between average global near-surface air temperatures and Atlantic SSTs and the effect of each on hurricane intensities over the past 50 years.

He found that the average air temperatures during the hurricane season months of July to November could predict sea surface temperatures but that the opposite was not true: SST could not be used to predict average air temperature.

Elsner says this supports recent studies linking rising SSTs to global warming.

"If natural variability of oceans were the driving force, you'd expect that you'd be able to predict the air temperatures from the sea surface temperatures, but you can't do that," he told LiveScience.

To conduct his study, Elsner used satellite data collected by the Intergovernmental Panel on Climate Change (IPCC) for air temperature information from National Oceanic and Atmospheric Administration (NOAA) for Atlantic SST records.

However, the reliability of such tropical cyclone databases was recently questioned by a group of scientists that included hurricane specialist Chris Landsea of the National Hurricane Center in Miami, Florida.

Questionable data?

Landsea cited changes in satellite technology in recent decades, differences in operational standards at tracking stations around the world and gaps in official records as reasons to question the use of cyclone databases for evaluating hurricane strengths over long periods of time.

Elsner says these problems do not apply to his study because he looked at year-to-year variations instead of trends over several years.

"The trend analysis is more susceptible to the changes in instrument records than is the type of regression analysis that I did," he said.

Elsner says his findings cannot be generalized to other oceans around the world and only applies to the Atlantic basin, and even then, only during the summer months.

"It could be that the ocean is actually forcing the atmosphere at other times of the year," Elsner said. "But during the hurricane season, it appears that it's going the other way-it's the atmosphere that's forcing the ocean."

In three future scenarios, the businesses foresee growing civil unrest, boom and bust economic cycles in Asia and mass migrations to Europe. But they also say scarcity will encourage the development of new water-saving technologies and better management of water by business.
The study of future water availability, which the corporations have taken three years to compile, suggests water conflicts are likely to become common in many countries, according to the World Business Council on Sustainable Development, which brought the industrial groups together.

Lloyd Timberlake, spokesman for the council, said: "The growing demand for water in China can potentially lead to over-exploitation and a decline in availability for domestic, agricultural, industry and energy production use. This inevitably leads to loss of production, both industrial and agricultural, and can also affect public health - all of which in turn will ultimately lead to an economic downturn. The question is how can business address these challenges and still make a profit."

The corporations were yesterday joined by the conservation group WWF and the International Water Management Institute, the world's leading body on fresh water management, which said water scarcity was increasing faster than expected. In China, authorities had begun trucking in water to millions of people after wells and rivers ran dry in the east of the country.

"Globally, water usage has increased by six times in the past 100 years and will double again by 2050, driven mainly by irrigation and demands of agriculture. Some countries have already run out of water to produce their own food. Without improvements ... the consequences will be even more widespread water scarcity and rapidly increasing water prices," said Frank Rijsberman, director of the institute.

The institute, funded by government research organisations, will report next week that a third of the world's population, more than 2 billion people, is living in places where water is overused - leading to falling underground water levels and drying rivers - or cannot be accessed.

Mr Rijsberman said rising living standards in India and China could lead to increased demand for better food, which would in turn need more water to produce. He expected the price of water to increase everywhere to meet an expected 50% increase in the amount of food the world will need in the next 20 years.

According to the institute's assessment, Egypt imports more than half of its food because it does not have enough water to grow it domestically and Australia is faced with water scarcity in the Murray-Darling Basin as a result of diverting large quantities of water for use in agriculture. The Aral Sea in central Asia is another example of massive diversion of water for agriculture in the Soviet era causing widespread water scarcity, and one of the world's worst environmental disasters.

Researchers say it is possible to reduce water scarcity, feed people and address poverty, but the key trade-off is with the environment. "People and their governments will face some tough decisions on how to allocate and manage water," says the institute's report.

In a further paper, WWF said yesterday that water crises, long seen as a problem of only the poorest, are affecting the wealthiest nations. "In Europe, countries along the Atlantic are suffering recurring droughts, while water-intensive tourism and irrigated agriculture are endangering water resources in the Mediterranean. In Australia, salinity is a major threat to a large proportion of its key agricultural areas", said Jamie Pittock, director of WWF's freshwater programme.

In the United States, Mr Pittock said, large areas are already using substantially more water than can be naturally replenished. "This situation will only be exacerbated as climate change is predicted to bring lower rainfall, increased evaporation and changed patterns of snow melting."

Three visions of the future

1. Misery and shortages in the megacities and drought in Africa

By 2010, 22 megacities with populations larger than 10 million face major water and sewerage problems. The situation is gravest in China, where 550 of the country's 600 largest cities are running short. Growing demand for water by industry leads to serious over-exploitaion with less and less water available for consumers and farmers. This leads to a fall in Chinese food production, which in turn leads to more imports and impacts on other countries. Friction and unrest grow worldwide as the middle classes struggle to pay bills. Businesses are exposed to charges of moral culpability and litigation over water use. Waves of immigrants flood in to Europe from increasingly drought-torn Africa

2. China leads recycling rush as world moves to a new hydro economy

By 2010, the water shortage in many developing countries is recognised as one of the most serious political and social issues of the time. Lack of water is stopping development and in many countries the rural poor suffer as their water and other needs take second place to those of swelling cities and industry. Local government worldwide is increasingly distrusted over water allocation, and historical divides between rich and poor are exacerbated by water shortages. However, by 2025 a worldwide hydro economy is developing, led by China. Vast new investments are made in recycling water and the cost of desalination is greatly reduced. Innovative small-scale water treatment processes become the norm

3. Water is the means of social control as floods and disease devastate world

Water becomes a key symbol of protest around the world and is seen as the most serious social and political issue of the generation. By 2015, multinational companies are accused regularly of taking too much water in developing countries, cholera breaks out in London, and governments start to use water as a form of social control, subsidising some sectors and rationing it to others. Great floods follow each other in quick succession. Deforestation leads to massive mudslides in Asia and increasing flooding affects Europe, damaging industry. A second New Orleans flood destroys the city again. Global focus grows on the "export" of water via crops such as wheat or fruit

Neighbouring Libya Tuesday dispatched by air humanitarian aid including tents, medicines and clothes to the disaster victims.

The Niger government and mining companies exploiting uranium in the north of the country have also distributed food and medicinal drugs.

Rain is quite rare in the northern desert of Niger, and a few tens of millimetres of rain are sometimes enough to crumble the houses built with clay mortar.

Located about 100 kilometres (60 miles) from Agadez, Ingal hosts a popular annual stock breeders' festival, whose 2006 edition is due next month.

The storm maintained winds of up to 83 km (52 miles) an hour at its center and was expected to bring up to 300 mm (12 inches) of rain to some parts of Kyushu, Japan's southernmost main island, by Friday morning.

Landfall on southern Kyushu was likely on Thursday night or possibly early on Friday, a Meteorological Agency official said, but added that the storm appeared to be shifting direction.

"The storm is likely to head in a more northern direction than previously expected, but its movements are extremely difficult to predict right now so almost anything is possible," he said.

The northerly shift means the storm is now likely to head up the Korean peninsula, according to the Tropical Storm Risk (www.tropicalstormrisk.com) Web site, which also predicted it would weaken to a tropical depression on Friday.

The Web site had earlier shown the storm heading toward the eastern Chinese provinces of Shandong and Jiangsu.

Doña Ana County Emergency Operations Center is receiving reports of the Rio Grande overflowing in the City of Sunland Park onto Racetrack Drive and at the Santa Teresa Bridge.

High river levels also are being reported near Radium Springs.

Residents throughout Doña Ana County who live near the Rio Grande are asked to remain vigilant as the river continues to rise.

No evacuations outside the Hatch area have been mandated, but rising water could result in people being asked to leave low-lying areas on short notice.

Heavy rains are being reported across Doña Ana County .

County road crews are standing by to deploy resources as necessary in affected areas.

The Doña Ana County Emergency Operations Center remains fully activated and staffed.