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Natural Hazards, UnNatural Disasters: The Economics of Effective Prevention

current climate, 10 percent of tropical cyclones are responsible for 90 percent of the expected damages. Even if climate does not change, damages will vary a great deal from year to year and decade to decade. Climate change is expected to skew the damage distribution of tropical cyclones and is likely to cause rare—but very powerful—tropical cyclones to become more common. With a warmed climate, the 10 percent of tropical cyclones that cause the most damage will be responsible for 93 percent of the expected damages. Climate change “fattens the tail” of the tropical cyclone damage distribution. For the United States, destructive storms that would come every 38 to 480 years given the current climate, would come every 18 to 89 years with future climate change. Figure 6.2 illustrates this for one specific climate model (MIROC).11 Most of the cyclones with and without climate change involve damages in the tens of billions of dollars or less. These storms may become even less frequent with climate change. But, very rarely, a very powerful storm will strike a very vulnerable location causing damages up to a trillion dollars. This seemingly small shift in the tail of the distribution is shown as “return years,” which show how many years would elapse, on average, between occurrences of a storm causing a specific level of damage (figure 6.2). Even though very rare and damaging storms are part of today’s climate, they will become more frequent in a warmer climate. For example, using the future baseline, a $100 billion storm is estimated to happen once in a hundred years in the United States given the current climate. With a future warmed climate, it is expected to happen once in about 56 years. Figure 6.2 Climate change shortens the return period of large storms

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Return period, log scale (years) Future

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Note: The figure shows the return period for tropical cyclones of different intensity in the United States for one specific climate model (MIROC). A $100 billion storm is estimated to happen once in a 100 years in the United States given the current climate. With a future warmed climate, it is expected to happen once in about 56 years. Source: Mendelsohn, Emanuel, and Chonabayashi 2010a.

Profile for World Bank Group Publications

Natural Hazards, UnNatural Disasters: The Economics of Effective Prevention  

Earthquakes, droughts, floods, and storms are natural hazards, but unnatural disasters are the deaths and damages that result from human act...

Natural Hazards, UnNatural Disasters: The Economics of Effective Prevention  

Earthquakes, droughts, floods, and storms are natural hazards, but unnatural disasters are the deaths and damages that result from human act...