Up in Smoke

By Keenon Hunsaker

A photo of the glowing sunset over Seattle caused by the smoke in the atmosphere from the Siberian fires taken on April 20th, 2015. More images can be found here.

The destructive power of wildfires is obvious when looking at the burnt landscapes it leaves in its path. But wildfires are more than a raging force of nature, they’re also a silent killer. Smoke is a second thought when it comes to how wildfires are dangerous but it can impact a much greater number of people than the flames themselves actually do. When a wildfire burns through an area a mixture of fine particles and gases are released into the air. The major gases released in the smoke are carbon monoxide, benzene, formaldehyde, acetaldehyde, acrolein, and polycyclic aromatic hydrocarbons (PAHs) which can combine to form fine particles and other harmful pollutants. These gases and fine particles interact with the atmosphere and the air we breathe to affect not only our health but the climate of the entire Earth.

If you’ve accidentally inhaled smoke from a camp fire or burnt something you were cooking it’s no surprise that breathing large amounts of it could be detrimental to your health. What you may not know is who is most effected by the smoke and what the effects are on the body. Most commonly the people who suffer the most from breathing pollutants emitted by wildfires are the young, elderly, and women that are pregnant. Children and pregnant women are more at risk during wildfires because they breathe a higher volume of air per pound than an average healthy adult. The elderly have a greater risk of negative effects of smoke inhalation because they may have pre-existing health conditions such as lung or heart disease that are worsened by the smoke. The symptoms of smoke inhalation range from mild irritations such as irritated eyes, coughing, scratchy throat, and headaches. To more severe effects such as bronchitis, asthma, cancer, and even death can occur if exposure to the pollutants is prolonged. When considering the huge amount of smoke released by wildfires it’s easy to see how an enormous number of people can feel these effects on their health. 

The amount of smoke alone is not the only factor to consider when looking into who’s effected. This is because the effects of wildfires are not isolated to the areas near where they occurred, but can be felt thousands of miles away from where they started. This is made possible by wind which not only helps spread fires and increases the intensity of the blaze but can also carry the smoke over oceans, through the atmosphere, great distances from its source. As Cliff Mass, University of Washington Professor of Atmospheric Sciences describes in his weather blog, farmers in Siberia often burn their fields from the previous year to provide fertilizer for the coming year’s crops but the wind this year was particularly strong causing the fires to burn wild. The fires not only burned homes and killed dozens of people but it also created a huge amount of smoke that went straight into the atmosphere. This smoke was then blown through the atmosphere by wind over the Pacific Ocean to the Pacific Northwest and eventually the rest of North America. The satellite images below taken by NASA show the smoke plume originating from Siberia and how it progressed towards the Pacific Northwest over a matter of several days. The smoke was also responsible for some radiant sunsets over Seattle for a few days although the people that had to breathe the smoke probably could have done without them. The sunsets may be nice to look at; however, they’re just the visual evidence of how smoke from wildfires interacts with the sun and effects our atmosphere. 

Satellite image of the huge amount of smoke in the atmosphere above Siberia caused by the fires on April 14th, 2015. Credit: NASA. 

satalite image
Satellite image of the smoke from the Siberian fire over the Pacific Ocean and just reaching Oregon on April 18th, 2015. Credit: NASA.

graph 1
This graph is showing the PM2.5 nephelometer readings for the month of April over the Seattle area. Around April 19th there is a spike in PM2.5 levels in the Seattle area. This is directly related to the Siberian fires and shows that some of the air pollution Seattle received is due to what’s occurring long distances away from the source and takes several days to travel that distance. 

2015 was the hottest year ever recorded on earth and had the worst fire season in Washington State history. How much worse was it? As Karin Bumbaco, the Assistant State Climatologist for Washington puts it, “The total number of acres burned from wildfires in 2015 exceeded 1 million for Washington State, and was the highest since the National Interagency Coordination Center began tracking these statistics in 2002." This is not a coincidence. The Earth is getting hotter and hotter every year and the Pacific Northwest is no exception according to projections by the University of Washington Climate Impacts Group. While precipitation projections show less certainty there is evidence that summer time precipitation levels for the Pacific Northwest could decrease significantly increasing the occurrence and effects of wildfires in the future. Lara Whitely Binder, an outreach and adaptation support specialist at the University of Washington Climate Impacts Group thinks that these factors are only going to increase the likelihood of wildfires, “climate change is expected to increase the risk of forest fires, particularly big fires, due to the combined effects of lower snowpack (which allows soil moisture to dry out earlier in the season) and warmer summer temperatures”. Creating the perfect conditions for extreme wildfire seasons like this past summer. 

graph 2
Historical and projected increase in temperature for Washington State through the year 2100. Darker black, red, and blue lines show the averaged values for all sources of temperature projections. RCPs are standardized values used to project climate change based on severity of global changes, 2.6 being the least severe and 8.5 being the most. (https://cig.uw.edu/learn/climate-change/)
graph 3
Projected change in monthly precipitation where DJF represents winter, MAM is spring, JJA is summer, and SON is fall. The horizontal line through the middle represents the average precipitation from 1950-1999. The darker bands within the colored bars represent the average for those projections and the place where the bands fall indicates whether the projection is above or below historical average. It can be seen that projections for summer precipitation are well below historical average. (https://cig.uw.edu/learn/climate-change/)

As we know wildfires release many different chemicals into the air as smoke including both aerosols and greenhouse gases. There are short term and long term effects on climate due to wildfires the initial, short-term effects are caused by the short lived aerosols that are released into the air as smoke that scatter and reflect incoming sunrays. As Mark Flanner, an Assistant Professor of Atmospheric, Oceanic and Space Sciences at the University of Michigan College of Engineering, explains, “[there is] an immediate, short term cooling effect at the surface by reducing sunlight absorption at the ground”. This effect is very short lived due to the nature of aerosols however, fires ultimately act to heat up the global atmosphere in the long run because greenhouse gases released such as CO2 can remain in the atmosphere for decades. This CO2 is released into the atmosphere mostly by the destruction of ground covering vegetation. Burning plants increases CO2 in two ways, first plants act as a major carbon sink or source that removes CO2 from the air and when they’re destroyed that sink no longer pulls CO2 from the air. Also trees store CO2 and when they are destroyed they release all that stored CO2 into the air significantly increasing the amount of CO2 released by wildfires. The way in which wildfires interact with the climate is complicated and varies depending on when and where they happen but the generally trend is that they increase the climate temperature.  

What isn’t complicated about wildfires is that they are contributing to climate change and negatively impacting people’s health. With the current trends wildfires will only increase in severity and impact more and more people each year. The impacts will not only be felt on their health but on the destruction of their environments caused by the fires itself and the effects of climate change. If something isn’t done now to decrease the trend of global warming wildfires will become more and more common until there’s nothing left to burn. 


KeenonKeenon Hunsaker is a pre-med biology major at UW Bothell who originally hails from Vancouver, Washington. “I care about the air we breathe because it not only effects humans but it also effects almost every other living organism on the planet.”