Californian Wildfires Were Once Extremely Common
Despite the recent widespread devastation from wildfires in California, fires in the state are rare events these days relative to the past. What Americans currently consider as extensive smoke and flames is actually rather paltry compared with conditions over two centuries ago.
That conclusion comes from researchers at the University of California, Berkeley who pieced together clues about how much land burned before European settlers arrived.
They estimate that before 1800, about 4.4 million acres or 7,000 square miles (18,000 square kilometres) of California went up in flames each year. This amounts to fire annually visiting over one-twentieth of the state. That's seven times the area that the massive wildfires burned in southern California during October 2007. The Berkeley researchers figure there used to be enough land ablaze to fill California's skies with smoke during much of summer and fall.
In fact, California's historical fires were almost as extensive as the entire area recently burned each year in the whole United States. Between 1994 and 2004, wildfires annually covered around 7,700 square miles throughout the country.
Scott L. Stephens, Robert E. Martin and Nicholas E. Clinton. 2007. Prehistoric fire area and emissions from California's forests, woodlands, shrublands, and grasslands. Forest Ecology and Management. 251(3): 205-216.