Hurricanes: The $500 billion storm?

As catastrophic and expensive as Hurricane Katrina was, chances are excellent that a costlier storm will strike the United States some year soon.

Hurricane-damage price tags have risen alarmingly in recent years, and no one knows the heights of the upper limits.

Consider that until two decades ago the nation had not experienced a hurricane that caused more than $1 billion in damage, including insurance losses and disaster payments.

But within the next two decades, the United States could get hit with a $500 billion storm, according to the University of Colorado's Roger Pielke Jr. and a team of hurricane experts.

Is this mankind at work, the price of global warming? While the role of global warming in hurricanes remains hotly debated, the hand of human activity is very much evident.

Development in storm-vulnerable areas is indisputably a major cost driver.

In raw dollars, Katrina was far and away the most-expensive hurricane ever, at $81 billion. And hurricane history suggests that a pricier one is all but inevitable.

Pielke and his colleagues have looked at historical storms and estimated what they would cost if they hit today, given the current levels of building and inflation -- the so-called normalized costs.

Using that calculation, Katrina isn't even No. 2. It falls to No. 3, with the most expensive storm -- the 1926 Miami hurricane -- costing almost twice as much.

The Galveston hurricane of 1900, the deadliest on record, is in second place.

Here is the Pielke Top 10 list, in 2009 dollars, in billions:

"Great Miami," 1926, $180.9

"Galveston," 1900, $94.1

Katrina, 2005, $91.5

"Galveston," 1915, $75.6

Andrew, 1992, $61.2

"Storm 11," 1944, $46.7

"New England," 1938, 45.2

Donna, 1960, $44.2

"Lake Okeechobee," 1928, $42.3

Camille, 1969, $25.6