Fires torch hundreds of thousands of acres in California.

Just a few short weeks ago I discussed the terrible hurricanes that affected Houston, the Caribbean Islands, and Florida this year. Now, the headlines are full of the wildfires that have been raging in California.

By late September, it had already been a heavy forest fire season in the western United States. Then, over the weekend of October 7-8, wildfires broke out in the area around the Napa and Sonoma Valleys. Fanned by hot, dry winds, they spread unbelievably quickly, burning 155,509 of acres (as of 10/17/2017), including prime wine producing vineyards, and thousands of homes (CALFIRE 2017b). Dozens were killed. Figure 1 shows the Coffee Park area of Santa Rosa in 2015. Figure 2 shows it after the fire. The gray areas are homes that have been burned – I mean burned to the ground, reduced to ashes. (City of Santa Rosa 2017)

Figure 1: Coffee Park Neighborhood, Santa Rosa CA, in 2015. Source: City of Santa Rosa.

Figure 2. Coffee Park Neighborhood, Santa Rosa CA, after the fire. Source: City of Santa Rosa.

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All totaled, as of 10/15/2017 CALFIRE lists 7,980 fires in California that have burned 1,046,995 acres (1,636 sq. mi.) (CALFIRE 2017b). Figure 3 shows a map of the fires. Maps such as this one tend not to be comprehensive, as they map the fires to which the specific agency has responded. (CALFIRE 2017a) Across the United States, as of 10/17/2017 there have been 51,435 wildfires that have burned 8,769,877 acres. That puts 2017 among the top 10 fire years ever, and compares to an average of 6,016,599 acres from 2006-2016. Figure 4 shows the data. Data collection methods changed after 1984, which is why I have used different colors for before and after that year. (National Interagency Fire Center)

Figure 3. Fires Responded to by CALFIRE in 2017. Source: CALFIRE, 2017.

Figure 4. Data source: National Interagency Fire Center, 2017.

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At a recent workshop of wildland fire experts, the consensus was that the United States was experiencing wildland fires that were behaving in aggressive, destructive ways that had never been experienced before. (National Academy of Sciences, Engineering, and Medicine 2017) What is going on?

In a series of posts last year, I explored the role that wildfire plays in western forests and showed that, though the number of fires did not seem to be trending higher, the number of acres burned per fire did. The result was that more acres per year were burning. There seemed to be 3 causes. One was that, while for decades fire was regarded as an unmitigated evil and suppressed as vigorously as possible, it was now regarded as a necessary part of forest ecology, and was allowed to burn without suppression efforts in some cases. A second reason was that decades of suppression had left western forests littered with dead and downed wood, perfect conditions for small fires to grow into huge raging crown fires that destroyed tens of thousands of acres. And a third reason was that climate change had raised summer temperatures, causing forests to dry out earlier in the season, turning small fires that would extinguish on their own into large, destructive fires.

Early fall is the driest time of year in the regions around the Napa and Sonoma Valleys. Typically, it has rained very little or not at all since March or April; the grasslands are brown and sere, the forests dry and brittle. Then, in October, the wind starts to blow: the Diablo Winds in Northern California, and the Santa Ana Winds in Southern California. Fueled by high pressure over the central United States and lower pressure over the coast, the winds rush over the Sierra Madre Mountains, down the passes and valleys, and through the lowlands. It happens every year. This year, when the fires started near the Napa and Sonoma Valleys, gusts were blowing at 79 m.p.h. Recent research suggests that the winds may be getting hotter and drier as a result of climate change. (Fountain, 2017)

Wildfire needs three things to grow, and it got all of them: warm temperatures, lots of dry fuel, and high winds that were hot and dry. The fires blew up into raging infernos. Blowing sparks along at 70+ m.p.h., the wind and the fire outraced the firefighters. In a span of only a few hours, tens of thousands of acres were reduced to ashes, whole neighborhoods were destroyed, and dozens were killed.

Hurricanes in the Atlantic, fires across the West, deluges and record heat in Australia, terrible floods in Asia, drought and desertification in some parts of Africa and floods in other parts: is Mother Nature mad at us? Is she exacting revenge for the way we have mistreated Her all these years? To borrow a thought from Abraham Lincoln: if we shall suppose that environmental destruction is an offense against Nature, and that humankind has caused that offense, and that suffering inevitably comes to those who commit such offenses, and if Nature now gives to us these terrible disasters as due to those who have caused the offenses, then shall we see in them anything but a judgment and a justice that is altogether true and righteous? “Woe unto the world because of offenses.” (Lincoln, 1865)

Sources:

CALFIRE. 2017a. Incident Information: Number of Fires and Acres. Viewed online 10/17/2017 at http://cdfdata.fire.ca.gov/incidents/incidents_stats?year=2017.

Cal Fire. 2017b. Statewide Fire Maps. Downloaded 2017-10-17 from http://www.fire.ca.gov/current_incidents.

City of Santa Rosa. 2017. Emergency Information Homepage: Fire Aerial Photo Comparison. Downloaded 2017-10-17 from https://www.srcity.org/2620/Emergency-Information.

Fountain, Henry. 2017. “California Winds are Fueling Fires. It May Be Getting Worse. New York Times, 10/11/2017. Viewed online 10/17/2017 at https://www.nytimes.com/2017/10/11/climate/caifornia-fires-wind.html?action=click&contentCollection=climate&region=rank&module=package&version=highlights&contentPlacement=1&pgtype=sectionfront.

Lincoln, Abraham. 1865. Second Inaugural Address. Viewed online 10/17/2017 at http://www.bartleby.com/124/pres32.html.

National Academies of Sciences, Engineering, and Medicine. 2017. A Century of Wildland Fire Research: Contributions to Long-term Approaches for Wildland Fire Manage- ment: Proceedings of a Workshop. Washington, DC: The National Academies Press. doi: https://doi. org/10.17226/24792. Downloaded 8/25/2017 from http://nap.edu/24792.
National Interagency Fire Center. Year-to-Date Statistics. Viewed online 10/17/2017 at https://www.nifc.gov/fireInfo/nfn.htm.