The plea follows an appeal for nearly $76.4 million announced in July. Just over half of that money has been received to date.

UN officials say the initial plan must be extended through the start of the next harvest in April 2007.

"While we are grateful for the generous contributions received thus far, there is an urgent and pressing need to continue assistance to drought and conflict affected communities across Afghanistan," said Secretary-General Kofi Annan's deputy special representative, Ameerah Haq.

Haq urged donor countries "to step forward with pledges that will enable us to provide vital food, and other essential living items as we approach the winter months."

The latest figures are in addition to the 6.5 million of Afghanistan's population of more than 30 million who constantly or seasonally suffer a lack of food.

food
Afghans pick up food rations supplied by the United Nations World Food Programme. (Photo by Richard Lee courtesy WFP)
Afghanistan is still recovering from a devastating drought between 1998 and 2003. Armed conflict between fighters loyal to the ousted Taliban regime and Afghan and international forces has made the effects of the current drought worse, particularly in the country's southern provinces.

The North Atlantic Treaty Organization, NATO, has deployed 31,000 soldiers across the country, and took over command of forces in the southern region July 31.

Today's appeal also includes assistance to an estimated 20,000 families displaced by the recent armed conflict in Uruzgan, Helmand and Kandahar provinces, said the UN, citing the Afghan government.

According to the Swiss charity ACT International, Action by Churches Together, most rain-fed crops, estimated to constitute 85 percent of the cultivated land, have failed. Some 2.5 million people are at risk mainly in the north, west and central regions of Afghanistan.

Agriculture accounts for 52 percent of the impoverished nation's gross domestic product, and wheat comprises 80 percent of cereal production.

Many water sources across Afghanistan have dried up. Due to the reduced availability of fodder, livestock mortality rates have increased and livestock prices have fallen.

Families with no reserves are migrating to other places for work. Women are suffering the most in meeting the needs of their families, and some families are so hard pressed that they see the "bride price" as a means of income and are marrying their daughters off early.

The water shortage could drive more farmers to grow opium poppies, the raw material for heroin, which requires less water than most other crops, such as wheat. The United Nations has estimated opium production will jump 60 percent this year in Afghanistan, a country that already produces more than 90 percent of the world's supplies.

Russia's invasion of Afghanistan in 1979 and subsequent civil wars and droughts over the past 25 years have created the world's largest refugee population with more than six million people fleeing their homes during that time, most of them to neighboring Pakistan and Iran. An estimated 2.6 million Afghans still live in Pakistan.

Although the river later dropped by about 2 inches, the water was expected to remain high through Thursday, said Jeff Kelley, emergency management coordinator for Orange County, about 100 miles northeast of Houston.

Kelley estimated about 40 homes had been destroyed as of Sunday. About 60 others were damaged, officials said.

Authorities in neighboring Hardin County estimated at least 100 homes had been damaged.

The Sabine River also was out of its banks. Officials in Newton County officials said at least three bridges have been washed out.

Officials continued assessing damage Monday. It varied from home to home because some had been built on stilts, while others sit at ground level. In some cases, water was up to the roof lines.

The area was hit hard by Rita last year, and Kelley said a number of
Federal Emergency Management Agency trailers were still in the area.

Gov. Rick Perry declared nine counties disaster areas. He also ordered state agencies to be on standby for rescue efforts if the remnants of Hurricane Paul bring more rain in the coming days. Paul was roaring toward the southern tip of the Baja California peninsula late Monday.

The study, "Feeling the Heat", says there are already an estimated 25 million environmental refugees, and this figure is likely to soar as rain patterns continue to change, floods and storms become more frequent and rising tides start to inundate low-lying countries such as Bangladesh or some of the Pacific islands.

Tearfund says that without urgent action, world governments will lose the fight to tackle the world water crisis and the growing threat of climate-change refugees in catastrophic numbers.

The report calls for governments at the UN Climate Change conference, beginning in Nairobi in a fortnight, to move towards a global framework for cutting climate-changing greenhouse gases such as carbon dioxide that goes beyond the existing climate treaty, the Kyoto protocol, and to commit billions more to help poor countries adapt to the coming changes.

"There will be millions more thirsty, hungry and ill poor people living in high-risk areas of the world by the end of the century," the report says. "It makes sense politically, economically and morally, for governments to act with urgency now."

Andy Atkins, advocacy director of Tearfund, said one of the most devastating impacts of climate change was on water supply. "In some parts of the world, floods, storms and poor rainfall are beginning to have catastrophic effects, threatening the lives and livelihoods of millions of people," he said.

This process will be steadily exacerbated, the report says, by the differing yet equally serious changes predicted to be part of a warming world. While some parts of the globe may experience much less rainfall and thus drought, others regions will have much more intense rain likely to bring about flooding. Sea-level rise , which a recent report suggested could be up to 50cm by 2050, would at that rate breach 100,000 kms (62,000 miles) of coastline around the world.

The report says: "As floods, drought and storms increase climate change will have a potentially catastrophic impact on water supply, threatening the lives and livelihoods of millions of people. Poor people - like the 80 per cent of Malawi's population who farm small plots - are reliant on rain for their harvests, and are least able to adapt to climate change. By exacerbating existing water stresses, climate change impacts many other areas of human development such as health and even industry."

It goes on: "Already, there are an estimated 25 million environmental refugees - more than half the number of political refugees. Experts such as the ecologist Norman Myers suggest this figure could soar to 200 million in less than 50 years. Unseen and uncounted, millions are already on the move in search of greater water security. In some countries, the exodus began years ago."

In the report's foreword, Sir John Houghton, former chairman of the Scientific Assessment Working Group of the Intergovernmental Panel on Climate Change, says politicians' strong words on climate change must now be matched by sufficient investment and strong action to cut global emissions, and help for the poorest nations adapt to climate change on their doorstep. A key to this will be helping poorer nations manage existing water supplies more efficiently.

"If your house is on fire, do you urgently try to save it, or throw your hands up in despair and walk away?" Sir John saysd. "Well, the house is on fire and it requires much more determined efforts to bring it under control and put it out. The UN climate change conference in Nairobi is an opportunity for failings to be addressed. Time is running out on us and world governments need to act much more responsibly, effectively and quickly."

The devastating impact

The report cites examples of where water problems are already causing a mass exodus or movement of people. They include:

* Poor crop yields are forcing more and more Mexicans to risk death by illegally fleeing to the US.

* One in five Brazilians born in the arid north-east of the country are moving to avoid drought.

* The spread of the Gobi desert, at a rate of 4,000 square miles a year, is forcing the populations of three provinces in China to abandon their homes.

* In Nigeria, 1,350 sq miles of land is turning to desert each year. Farmers and herdsmen are being forced to move to the cities.

* The population of Tuvalu, a group of eight Pacific islands north-east of Australia, is already being evacuated; nearly 3,000 Tuvalans have left so far.

"When most people think about climate change, they think of heat stress from heat waves," said Cindy Parker, M.D., of the Johns Hopkins Bloomberg School of Public Health in Baltimore. "The heat wave in Western Europe in 2003 killed in excess of 30,000 people who wouldn't have died otherwise. With climate change, heat waves will become more severe, and last for longer periods of time."

"Scientists (in the U.S.) haven't done a good job of communicating why climate change is important to regular people," said Parker, who was invited to give a presentation on the health hazards of global warming at the Annual Meeting of the Geological Society of America in Philadelphia. Parker will speak in a Pardee Keynote Symposium on Sunday, 22 October.

"The other thing that has gotten a lot of media attention is the increased risk of infectious diseases," said Parker. "This is of greater concern to other parts of the world than the United States." That's because the U.S. has good public health systems that can track down infectious diseases, such as malaria, and intervene so they don't spread, she said.

"In my professional opinion, some of the less direct impacts will be much more devastating for us," said Parker.

Hurricane Katrina was a primer on the matter. Global warming will bring bigger storms and hurricanes that will hold more water, according to climate scientists. Katrina showed how the water from a hurricane does far more damage than the high winds. All that flooding brings with it a host of direct and indirect health problems.

"As we saw from New Orleans, we're not good at evacuating people during storms." What's worse, she said, you can't evacuate critical infrastructure. "Our biggest medical centers have been built in our larger cities."

Thirteen of the 20 largest cities on earth are located at sea level on coasts, Parker points out. "As sea level rises, there go our medical institutions, water treatment plants, emergency response units such as fire departments and ambulances. The bulk of the services designed to keep us healthy are almost all located in our larger cities, which are also located frequently at sea level."

Then there is the matter of water. Clean water is one of the most basic and critical health needs. But climate change is threatening water supply quantities in many areas as well as water quality.

"Even without climate change, water is already in short supply," said Parker. "But under changed climate conditions, precipitation patterns are expected to change." That means droughts and famines could become more prominent.

Worsening water quality is expected to go hand-in-hand with the continuing deterioration of the natural ecosystems all around us.

"We rely on our ecosystems to provide very basic services to us," Parker explained. "Despite our technology, we can't live without clean water, clean air, and soil to produce food. We rely on healthy ecosystems to provide these basic and absolute necessities."

Forests, for example, absorb carbon dioxide from the environment, photosynthesize, and release oxygen as a waste product, which is essential for animal life. Similarly, with water, a healthy ecosystem such as a forest or wetland can filter a lot of toxins out of water and provide us with clean drinking water.

Water supplies and water quality are already major health problems worldwide. In most years, drought and famine cause more than half of all deaths from natural disasters. Already 1.8 million people, mostly children, die each year from diarrheal diseases caused by contaminated water. Climate change will just make this worse, Parker says.

Another absolute and basic need is, of course, food. That's also facing trouble, says Parker. Climate change will bring huge changes to how we grow food. Studies are mounting that show crops are likely to be more negatively affected by climate change than previously thought. "We need to steel ourselves from changes and, quite likely, reductions in food supplies from around the world."

All these changes, plus displacements of millions of people as was seen after Hurricane Katrina, pose health threats for everyone. But the most vulnerable members of our societies will be hardest hit, such as children, elders, city dwellers, and those who are socio-economically disadvantaged, says Parker. Planning for these threats and taking measures to minimize impacts is happening much too slowly, she said.

"These measures don't necessarily require a lot of money and we already have the new technology," she said. "I'm a preventive medicine physician, and I use that training and way of thinking with respect to climate change as well. It makes a whole lot more sense to me to prevent our climate from more instability rather than waiting and putting our research and resources into trying to fix problems after they've happened."

The viruses are called picornaviruses and infect more than 1 billion people worldwide each year. They include the virus that causes polio, as well as colds and diarrhea. People contract two or three such infections a year on average.

"We think picornavirus family members cross into the brain and cause a variety of brain injuries. For example, the polio virus can cause paralysis," Howe said.

"It can injure the spinal cord and different parts of the brain responsible for motor function. In the murine (mouse) virus we studied, it did the same thing and also injured parts of the brain responsible for memory."

The Mayo Clinic infected mice with a virus called Theiler's murine encephalomyelitis virus, which is similar to human poliovirus.

Infected mice later had difficulty learning to navigate a maze. Some were barely affected, while others were completely unable to manage, and when the mice were killed and their brains examined, a correlating amount of damage was seen in the hippocampus region, related to learning and memory.

One virus particularly likely to cause brain damage is enterovirus 71, which is common in Asia, the researchers said. It can cross over into the brain and cause encephalitis, a brain inflammation that can lead to coma and death.

"Our findings suggest that picornavirus infections throughout the lifetime of an individual may chip away at the cognitive reserve, increasing the likelihood of detectable cognitive impairment as the individual ages," the researchers wrote in their report.

"We hypothesize that mild memory and cognitive impairments of unknown etiology may, in fact, be due to accumulative loss of hippocampus function caused by repeated infection with common and widespread neurovirulent picornaviruses."

Other viruses are known to kill brain cells, including the herpes virus and human immunodeficiency virus or HIV.