WASHINGTON (AP)—Global warming is leading to such severe storms,droughts and heat waves that nations should prepare for anunprecedented onslaught of deadly and costly weather disasters, aninternational panel of climate scientists said in a newreport issued Wednesday.

The greatest threat from extreme weather is to highly populated,poor regions of the world, the report warns, but no corner of theglobe—from Mumbai to Miami—is immune. The document by a NobelPrize-winning panel of climate scientists forecastsstronger tropical cyclones and more frequent heat waves, delugesand droughts.

The 594-page report blames the scale of recent and futuredisasters on a combination of man-made climate change,population shifts and poverty.

In the past, the Intergovernmental Panelon Climate Change, founded in 1988 by the United Nations,has focused on the slow inexorable rise of temperatures and oceansas part of global warming. This report by the panel is the first tolook at the less common but far more noticeable extremeweather changes, which lately have been costing on averageabout $80 billion a year in damage.

“We mostly experience weather and climate through theextreme,” said one of the report's top editors, Chris Field, anecologist with the Carnegie Institution of Washington. “That'swhere we have the losses. That's where we have the insurancepayments. That's where things have the potential to fall apart.

“There are lots of places that are already marginal for onereason or another,” Field said. But it's not just poor areas:“There is disaster risk almost everywhere.”

The report specifically points to New Orleans during 2005'sHurricane Katrina, noting that “developed countries also suffersevere disasters because of social vulnerability and inadequatedisaster protection.”

In coastal areas of the United States, property damage fromhurricanes and rising seas could increase by 20 percent by 2030,the report said. And in parts of Texas, the area vulnerable tostorm surge could more than double by 2080.

Already U.S. insured losses from weather disasters have soaredfrom an average of about $3 billion a year in the 1980s to about$20 billion a year in the last decade, even after adjusting forinflation, said Mark Way, director of sustainability at insurancegiant Swiss Re. Last year that total rose to $35 billion, but muchof that was from tornadoes, which scientists are unable to connectwith global warming. U.S. insured losses are just a fraction of theoverall damage from weather disasters each year.

Globally, the scientists say that some places, particularlyparts of Mumbai in India, could become uninhabitable from floods,storms and rising seas. In 2005, over 24 hours nearly 3 feet ofrain fell on the city, killing more than 1,000 people and causingmassive damage. Roughly 2.7 million people live in areas at risk offlooding.

Other cities at lesser risk include Miami, Shanghai, Bangkok,China's Guangzhou, Vietnam's Ho Chi Minh City, Myanmar's Yangon(formerly known as Rangoon) and India's Kolkata (formerly known asCalcutta). The people of small island nations, such as theMaldives, may also need to abandon their homes because of risingseas and fierce storms.

“The decision about whether or not to move is achingly difficultand I think it's one that the world community will have to facewith increasing frequency in the future,” Field said in a telephonenews conference Wednesday.

This report—the summary of which was issued in November—isunique because it emphasizes managing risks and how takingprecautions can work, Field said. In fact, the panel's report usesthe word “risk” 4,387 times.

Field pointed to storm-and-flood-prone Bangladesh, animpoverished country that has learned from its past disasters. In1970, a Category 3 tropical cyclone named Bhola killed more than300,000 people. In 2007, the stronger cyclone Sidr killed only4,200 people. Despite the loss of life, Bangladesh is considered asuccess story because it was better prepared and invested inwarning and disaster prevention, Field said.

A country that was not as prepared, Myanmar, was hit with asimilar sized storm in 2008, which killed 138,000 people.

The study forecasts that some tropical cyclones—which includehurricanes in the United States—will be stronger because of globalwarming. But the number of storms is not predicted to increase andmay drop slightly.

Some other specific changes in severe weather that thescientists said they had the most confidence in predicting includemore heat waves and record hot temperatures worldwide and increaseddownpours in Alaska, Canada, northern and central Europe, EastAfrica and north Asia,

IPCC Chairman Rajendra Pachauri told The Associated Press thatwhile all countries are hurt by increasedclimate extremes, theoverwhelming majority of deaths occur in poorer, less developedplaces. Yet, it is wealthy nations that produce more greenhousegases from burning fossil fuels, raising the issue of fairness.

Some weather extremes aren't deadly, however. Sometimes, theyare just strange.

Report co-author David Easterling of theNational Climatic Data Center says this month's U.S. heatwave, while not deadly, fits the pattern of worsening extremes. TheU.S. has set nearly 6,800 high temperature records in March. Lastyear, the United States set a record for billion-dollar weatherdisasters, though many were tornadoes.

“When you start putting all these events together, the insuranceclaims, it's just amazing,” Easterling said. “It's pretty hard todeny the fact that there's got to besome climate signal.”

Northeastern University engineering and environment professorAuroop Ganguly, who didn't take part in writing the IPCC report,praised it and said the extreme weather it highlights “is one ofthe major and important types of what we would call 'globalweirding.'” It's a phrase that some experts have been starting touse more to describe climate extremes.

Field doesn't consider the term inaccurate, but he doesn't useit.

“It feels to me like it might give the impression we are talkingabout amusing little stuff when we are, in fact, talking aboutevents and trends with the potential to have serious impacts onlarge numbers of people.”