For over a week, wildfires have raged along the Western Coast of the United States, causing mass evacuations and mass stay-indoors orders as air quality has registered as hazardous across much of the West Coast.
Any seasoned Californian can tell you that fire season is just beginning, but this season is already set apart from the others. Records have been set in California, with 2020 producing three of the four largest wildfires in the state resulting in 2.2 million acres burned this year in 29 major wildfires compared with a five-year average of only just under 310,000 acres burned in the state annually. In Oregon, the ten-year average for a typical fire season was about 500,000 acres burned but by Monday, September 14, over one million acres statewide had burned.
How Wildfires Are Linked to Climate Change
Climate change is linked to a number of wildfire risk factors, including increased temperatures, a reduction of soil moisture, and dryer forest fuels such as trees and shrubs. While wildfires were certainly a problem in the past, the number of large fires has doubled between 1984 and 2015 in the western United States and climate change has played a role in that increase. Not only do the warmer, drier conditions created by climate change make it easier for wildfires to spread, climate change has also contributed to a longer fire season.
The Public Health Tie-In
While 40,000 Oregonians were evacuated, countless others were confined to their homes as hazardous air quality loomed over the state. At many points during the weekend the air quality in Portland, Oregon registered as the worst of any city on the planet. The main culprit of the poor air quality is particulate matter from the wildfire smoke, and research has linked exposure to particulate matter from wildfires to lung and heart problems, worse flu seasons, increased hospital visits. On Sunday in Multnomah County, the home of Portland, particulate matter numbers peaked at 536.5 micrograms per cubic meter (ug/m3) and the 24-hour average sat at 478ug/m3, the highest levels on record for the county. In addition to the standard advice of closing doors and windows, residents of Multnomah County were told to avoid vacuuming, frying, broiling, using gas stoves, or burning candles or incense so as to not add to indoor air pollution.
Public health officials are also warning that those who have been diagnosed with COVID-19 are at higher risk from smoke exposure, putting them in the high-risk category along with residents with heart or lung conditions, infants and children, older adults, and pregnant people.
While the hazardous air quality would be concerning in any year, this year it has the potential to be particularly destructive. A study from the University of Montana analyzed a decade of Montana state wildfire and flu data and concluded that there was a correlation between bad wildfire and bad flu seasons, with lead researcher Erin Landguth saying "one would expect to see a three to five times worse flu season in Montana associated with after a bad fire season." The exact reason is unknown, but some studies have shown that wildfire smoke results in a suppressed immune system in animals. Further research is underway.
The Implications for Urban Policy
Climate change scientists have long known that some areas will experience extreme heat and longer and more frequent droughts as the concentration of carbon dioxide builds up in our atmosphere. It's not a far jump from there to increased wildfire seasons. However, the one big thing that has changed recently? The density of housing in areas that have been experiencing wildfires for decades.
California's housing shortage has lead them to allow more development in the urban fringe, areas where housing can be built cheaply but come with ideal conditions for wildfires. An estimated $1.5 billion in insured losses was calculated based on a loss of 1,800 from wildfires in California in late August. By mid-September, at least 4,200 structures had been destroyed in the state. The risks of living in these areas have increased so much that private companies have begun to refuse to insure homes in some locations, and state-regulated insurers have had to step in.
The state stepping in to insure homes that will be rebuilt in the same urban fringe and continue to burn year after year is unsustainable. Eventually, a new policy will have to be pursued. That could be a form of managed retreat, a policy that has until this point largely focused on retreat from sea level rise. Managed retreat policies could include a stipulation in an insurance claim that the home must be rebuilt elsewhere, outside of a high wildfire risk area. They could also take the form of incentives for homeowners to sell and relocate elsewhere prior to a wildfire. The only certain thing about this situation is that within the near future, there will be population shifts as residents tire of living with wildfire risks for many months out of the year.