Since the year 2000, the largest wildfire in almost every American western state has occurred. As we have seen on the news recently, wildfires possess a capability to completely obliterate anything in its path. Along with infrastructure and economic damage as threats, these wildfires put plumes of fine particulates in the air which causes health damage. These particulates extend far past where the initial spark occurred. Thanks to the atmosphere, the particulates can travel hundreds—If not—thousands of miles away from the fire and have an effect on the air elsewhere.
An analysis of PM2.5, particulate matter smaller than 2.5 microns in diameter, showed that through worsening wildfires, air quality in turn decreases due to the increase in PM2.5. The EPA has established a federal 24-hour PM2.5 standard of 35 micrograms per cubic meter which is the standard for healthy human consumption. In the Sacramento and San Joaquin Valleys, the number of days for which PM2.5 exceeded the EPA standard declined during 2000 through 2016. This decline in the 16-year average can be attributed to efforts to decrease industrial emissions. However, the number of days of exceedances each year during the California wildfire season (June through September) has been increasing. With stronger and more frequent wildfires, this number will increase due to the abundance of PM2.5. Also, longer wildfire seasons are currently being observed, so with this, even more PM2.5 will likely be present in the atmosphere.
Speaking of longer wildfire seasons, in the Pacific Northwest along with other western states, seasons are now on average 105 days longer than what they were in the 1970s. With these longer seasons, stronger fires occur as well. For instance, Idaho has experienced more than 10 times as many large fires (more than 1000 acres) in a typical year since the 70s. Oregon and Washington are 7 times as many and 5 times as many, respectively.
The American West in recent years has experienced more frequent and stronger wildfires as a result of a drying climate. Efforts to clean the air and to remain below the PM2.5 35 micrograms per cubic meter standard set by the EPA, will be facing a harder challenge in coming years. As said above, air pollution progress is quantifiable and can be observed, but so can the increase in PM2.5.
To read Climate Central’s full analysis go, here.
To learn about more air quality issues click, here.
©2018 Weather Forecaster Alec Kownacki