In the path of disaster

Is there any pattern to hurricanes?

Yes—and history would suggest that 2004 will not be a one-year aberration. Over the past century of recorded weather observations, hurricane activity has run in fairly consistent cycles tied to fluctuations in ocean temperatures. For about 40 years, there is a long cycle of frequent hurricane activity, then a lull of about 25 years during which fewer hurricanes are born. Hurricane experts say that we were in a lull between 1970 and 1995, and have now entered a prolonged busy period. During the lull, the U.S. was hit with only one or two hurricanes a year with winds exceeding 111 mph. But starting in 1995, there have been three or more major storms every year except one. For the next 10 to 30 years, forecasters say, people living in Florida, the Southeast, and Texas can expect to be hit by at least three major hurricanes like Charley, Frances, and Ivan every year. “Get used to it,” said The Miami Herald. “This is the new normal.”

What changed?

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Ocean temperatures. Hurricanes are born in the warm waters of the Atlantic Ocean, a little north of the equator and just west of the Cape Verdi islands. There, when ocean temperatures are at least 80 degrees, literally tons of warm water evaporates and is picked up by passing trade winds. The moisture rises with the warm air and condenses into water droplets and clouds. The process of condensation releases more heat into the column of air, and it rises faster and with great energy; when conditions are right, this conveyor belt of moisture and warmth creates a spiraling vortex that sucks up more moisture from the ocean. The process feeds on itself, and with enough moisture and wind, these storms grow into the monsters we call hurricanes. This year, the Atlantic Ocean near the equator is 1 to 2 degrees warmer than normal, increasing the rate of evaporation and the amount of moisture and clouds in the air. As a result, this has already been the worst hurricane season in 40 years, and it’s only half over. “This year, so far, has been Mother Nature’s payback year,” said Tony Cristaldi of the National Weather Service.

Has this happened before?

Yes. The 1920s and ’30s were particularly rough. In 1926 and 1928, two devastating hurricanes hit Miami head-on, flooding vast sections of the city and reducing thousands of homes and buildings to piles of soggy, shredded wood. The 1928 storm killed 3,000 people as it plowed through the state. Then, on Labor Day 1935, a hurricane with sustained winds of more than 155 mph whirled into the Florida Keys. It propelled surging seas over the entirety of Key West and other islands in that chain, killed 435 people, and washed out 40 miles of the Overseas Railroad, which connected Key West to the mainland.

Aren’t buildings stronger today?

Yes, but many of them are still not strong enough to withstand a Category 4 or 5 hurricane, the most powerful. And over the last half-century, millions of people have migrated to the warm climate of the Southeast, many of them building homes in low-lying areas or just steps from the churning sea. Today, there are far more buildings for storms to rip apart, and far more people to displace, injure, or kill. In the 1960s, there were just 45 million people living in the hurricane-prone Southeast. Since then, its population has grown three times faster than the rest of the country’s. By 2010 there could be more than 73 million people in hurricane country. “Every time I look around, there’s a new high-rise going up,” said meteorologist Jerry Jarrell, the former director of the National Hurricane Center in South Florida. Many experts predict that some of the new construction will be reduced to splinters in a major hurricane.

Why is that?

Florida Gov. Jeb Bush calls it “hurricane amnesia.” Making buildings hurricane worthy adds about 8 percent to the total cost—not much when you consider how often the region is hit. But to save time or money, many builders cheat. In their eagerness to promote development, some local officials let them get away with it. In 1992, Hurricane Andrew exposed the shoddy construction and poor enforcement of regulations in the new cookie-cutter suburbs south of Miami. The storm’s 150-mph winds flattened housing complexes and demolished blocks of new stores. The community known as Homestead looked as if it had been bombed. Andrew’s damages were estimated at $30 billion, the worst in U.S. history. But the destruction wrought by Andrew is likely to be surpassed in coming years, hurricane experts say, especially if the earth’s climate continues to warm.

What role could global warming play?

If the oceans grow warmer, they may spawn more powerful hurricanes than any we’ve ever seen. For every degree that water temperature rises, MIT atmospheric scientist Kerry Emanuel says, maximum storm winds increase 5 mph. In theory, a warmer Atlantic could, in a decade or two, begin producing superviolent hurricanes with winds exceeding 175 mph or even 200 mph. Since the power unleashed by these storms increases exponentially with wind speed, a 200-mph hurricane wouldn’t be merely twice as strong as a 100-mph storm; it would be dozens of times stronger. “We do know that hurricane intensity is directly correlated to how warm the ocean waters are,” says Dan Petersen, a meteorologist with the U.S. National Weather Service. “And if global warming continues to occur, and this results in warmer water temperatures, then we’ll see an undeniable signal of stronger hurricanes.”

Fury by any other name