Since 1980, the Southeast and Midwest U.S. states have experienced the greatest number of billion-dollar weather/climate disasters (Figure 1.4). This is not unexpected since these are the regions most susceptible to the impact of Atlantic hurricanes and most conducive to the formation of strong tornadoes. In addition, these regions include the dry, subtropical portion of the United States that, as outlined in Section 6, is likely to experience increased incidence of drought and wildfire outbreaks.
Figure 1.4. Map showing the distribution of billion-dollar weather/climate disasters in the United States from 1980 to 2011. The map shows where the damages associated with each of the 134 billion-dollar events listed in Table 1.1 were located. A single billion-dollar disaster can be distributed across, and hence included in the data for, several states. Source: http://www.ncdc.noaa.gov/billions/.
1.2 Weather and climate Weather is the state of the atmosphere at a particular time and place. Climate, on the other hand, gives the likelihood of occurrence of a particular weather event. Another way of looking at climate is that it is the statistics of weather. Climate is what you expect; weather is what you get. It’s important to recognize that when climate scientists make projections of future changes in climate, they are not making long-range weather predictions. Instead, they are making predictions of the change in the statistics of weather. In climate prediction, we examine how the shape of the distribution of a particular aspect of weather, such as temperature or precipitation, changes in the future. We might make predictions of the change in mean temperature or the change in the likelihood of occurrence of a particular extreme precipitation event. An example is provided in Figure 1.5. Each of the three panels shows two curves: a present-day curve (“Previous climate”) and a future climate curve (“New climate”). The present-day curve is Determining the Impact of Climate Change on Insurance Risk and the Global Community
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