Billion Dollar Disasters

2014 in Context

In 2014, there were 8 weather and climate disaster events with losses exceeding $1 billion each across the United States. These events included a drought event, a flooding event, 5 severe storm events, and a winter storm event. Overall, these events resulted in the deaths of 53 people and had significant economic effects on the areas impacted. Further cost data and figures on individual events in 2014 will be announced in mid-2015.

Methodology and Data Sources

In 2012, NOAA's National Climatic Data Center reviewed its methodology on how NCDC develops Billion-dollar Disasters. NCDC held a workshop with economic experts (May, 2012) and worked with a consulting partner to examine possible inaccuracy and biases in the data sources and methodology used in developing the loss assessments (mid-2013). This ensures more consistency with the numbers NCDC provides on a yearly basis and give more confidence in the year-to-year comparison of information. Another outcome is a published peer-reviewed article "U.S. Billion-dollar Weather and Climate Disasters: Data Sources, Trends, Accuracy and Biases". This research article found the net effect of all biases appears to be an underestimation of average loss. In particular, it is shown that the factor approach can result in an underestimation of average loss of approximately 10–15%. This bias was corrected during a reanalysis of the loss data to reflect new loss totals.

It is also known that the uncertainty of loss estimates differ by disaster event type reflecting the quality and completeness of the data sources used in our loss estimation. In 2014, two of the eight billion-dollar events (i.e., the drought and flooding event) have higher potential uncertainty values around the loss estimates due to less coverage of insured assets. The remaining 6 events (i.e., 5 severe local storms and a winter storm) have lower potential uncertainty surrounding their estimate due to more complete insurance coverage. To that end, we have temporarily rounded our loss estimates to the nearest billion dollars while developing research to define uncertainty and confidence intervals surrounding these estimates.

In performing these disaster cost assessments these statistics were taken from a wide variety of sources and represent, to the best of our ability, the estimated total costs of these events -- that is, the costs in terms of dollars that would not have been incurred had the event not taken place. Insured and uninsured losses are included in damage estimates. Sources include the National Weather Service, the Federal Emergency Management Agency, U.S. Department of Agriculture, other U.S. government agencies, individual state emergency management agencies, state and regional climate centers, media reports, and insurance industry estimates.

http://www.ncdc.noaa.gov/billions/