The Impact of Climate Change and Population Growth on the National Flood Insurance Program Through 2100

This report prepared by AECOM was commissioned by the Federal Emergency Management Agency (FEMA) to analyze potential long-term effects of  climate change on the National Flood Insurance Program (NFIP). Through this study, FEMA hopes to understand the potential impact of climate change on the financial strength of the NFIP, and recommend options to increase the NFIP’s viability. The climate change impact assessment includes all 50 states, as well as consideration of the U.S. territories, where attention was given primarily to areas of greatest population and the largest inventory of at-risk properties.

According to the report, the amount of land in the U.S. that is vulnerable to an 100-year flood event may increase by approximately 45 percent in riverine floodplains, and 55 percent in coastal floodplains where the shoreline is “fixed” (i.e., stabilized through beach nourishment and other activities). Areas classified as part of a floodplain would increase by over 100 percent for portions of the Gulf of Mexico and the Atlantic coasts, and less than 50 percent along the Pacific Coast.

The causes of these increases in floodplain are attributed changes in the climate (70 percent) and population growth (30 percent). These changes in flood patterns will have important economic consequences on the cost of insurance, the number of households that will be required to carry insurance, and on the long-term solvency of the NFIP.  The report projects that the number of flood insurance policies under the NFIP will grow by approximately 80 percent if shorelines are allowed to recede and 130 percent if shorelines are fixed. Nationally the number of flood insurance policies for coastal areas would more than double, with the cost of the average insurance payouts increasing by 90 percent by 2100.  In turn, insurance rates would need to rise by upwards of 40 percent (or 70 percent in coastal floodplains) through the year 2100 to offset these projected increases in claims. 

The report also provides some technical recommendations for improving and refining the study to provide more detailed analysis at a local-scale, such as expanding and improving NFIP data collection to include accurate geospatial data on policies, claims, structures and their values. 

At the request of the Government Accountability Office, FEMA funded this study in November 2008 on the effects of climate change and population growth on NFIP.  FEMA contracted with AECOM, in partnership with Michael Baker Jr., Inc. and Deloitte Consulting, LLP, to conduct an independent study and present the findings and recommendations to FEMA.


Publication Date: June 12, 2013

Related Organizations:


Resource Category:

Resource Types:

  • Assessment


Go To Resource