LONDON (AP) _ The world has experienced unusually extreme weather in recent decades and economic losses from storms and other catastrophes have increased tenfold, an independent research group reported.
The World Water Council said Thursday that more intense rainy seasons, longer dry seasons, stronger storms, and rising sea levels had helped cause an increasing number of disastrous floods and droughts.
Global warming is causing the changes in weather patterns, while growing populations and migration to vulnerable areas is increasing the cost of each disaster, said William Cosgrove, vice president of the World Water Council.
``The forecast is that it's going to continue to get worse unless we start to take actions to mitigate global warming,'' he said.
Between 1971 and 1995, the group reported, floods affected more than 1.5 billion people around the world. About 318,000 people died because of floods and more than 81 million were made homeless, the council said.
The figures were culled from research done by scientists at the Dialogue on Water and Climate, as well as papers by researchers from other groups. The findings will be presented in greater detail at the World Water Forum, scheduled to be held next month in Kyoto, Japan, site of negotiations for the global warming protocol that was rejected by President Bush.
The council quoted climate experts as predicting changes in the next century would lead to shorter and more intense rainy seasons in some areas and longer droughts in others, endangering some crops and species and causing a drop in global food production.
Rising sea levels pose a serious threat to small island nations, low-lying countries like Bangladesh and the Netherlands and major cities like New York, Tokyo, Buenos Aires, Argentina, and Lagos, Nigeria, the group warned.
Sea levels are expected to rise by 19 inches between 1990 and 2100, the scientists estimated.
``Even if we were to stop all carbon dioxide emissions today, global warming is going to continue,'' Cosgrove said. ``As a consequence, the sea is going to continue expanding and rising.''
Carbon dioxide is among the ``greenhouse gases'' blamed for warming the earth. While most climate experts agree pollution is responsible, a few remain skeptical.
The White House says humans clearly are agents of environmental change but says it is unclear to what degree. Bush has called for more research on warming, a stance criticized this week by a National Academy of Sciences panel.
While scientists could not say exactly how much the incidence of extreme weather had increased, Cosgrove said records for storms, floods and droughts were being broken every year, killing thousands and causing serious economic disruption.
``Most countries aren't ready to deal adequately with the severe natural disasters that we get now, a situation that will become much worse,'' he said.
The council said there were 26 ``major flood disasters'' worldwide in the 1990s, compared to 18 in the 1980s, eight in the 1970s, seven in the 1960s and six in the 1950s. The largest number of severe floods occurred in Asia, the council said.
Overall, precipitation worldwide has increased by about 2 percent since 1900, the group said.
Poor nations tend to suffer far more than wealthier ones when hit by weather disasters, both in terms of human casualties and economic loss, the council said.
While 2000 flooding in Mozambique cut the southern African country's gross domestic product by 45 percent, severe floods last year in Germany were blamed for just a one percent decline in GDP, the group said, citing World Bank figures.
Hurricane Mitch had a devastating impact when it walloped Central America in 1998, killing thousands and causing billions of dollars in damage.
Cosgrove blamed the difference in impacts partly on growing populations in poor countries and migration to risky or environmentally damaged areas such as flood plains or bare mountainsides at risk of mudslides.
In drought-prone regions, growing populations put more pressure on food and water supplies and mean shortages happen faster when rains stop, he said.
The group also said droughts were growing more severe and widespread, accounting for up to 45 percent of reported deaths from natural disasters between 1992 and 2001.