Of the 20 largest fires documented by the California Department of Forestry and Fire Protection, 11 have occurred since the year 2000 and five in the last two years.

This trend toward more destructive fires is a national one. Across the country, the average land area burned during wildfires has more than doubled since the 1970s from 3 million to 7 million acres.

San Diego State researchers studying the 2003 San Diego fires—the most devastating in California in terms of acreage burned and lives lost—looked at factors not typically analyzed after a major wildfire. They found that the actual economic impact of the Cedar and Paradise fires was $2 billion-plus more than estimated.

Why such a large disparity? Because historically, reports about the economic impacts of wildfires have looked at suppression costs, federal assistance and loss of property. They neglected to analyze long-term impacts, such as watershed and water quality mitigation, sensitive species and habitat restorations, and bond offerings for firefighting investments.

The real cost of the 2003 wildfires should account for disruptions to transportation and business, including San Diego’s tourism industry, as well as damage to infrastructure, according to Matt Rahn, director of research and education at SDSU’s Field Stations Programs, who led the study.

“Think about the effects of shutting down the city of San Diego for a couple of days, which is essentially what happened,” Rahn said.

The study includes recommendations for improving cost assessments and helping the state prepare for future wildfires. Among them are: developing a statistically valid and standardized protocol for future damage assessments; devising a strategy to assess impacts to cultural and historic resources; and ensuring adequate staffing and resources for effective response.