In the first part of this piece on Wildfires and Us, I discussed the emotional and cultural influences that have shaped our collective view on wildfire. In this addendum to that article, I want to share what the best available science and experts have taught me about taking a rational and fact-based approach to our Pacific Northwest forests and our relationship to fire.
Homes and Communities
Fires are healthy for backcountry forests, yet we still need to protect human structures from the flames and wind-driven embers. Forest scientists and fire behavior experts like Jack Cohen have worked with the National Fire Protection Association and the insurance industry to test the best methods for fireproofing homes and removing flammable materials immediately around them to create defensible space. Los Angeles is a leader in encouraging fire-safe principles for homes. As a result, the La Tuna fire burned only five of the nearly 1,400 homes in its path. The five that burned either escaped LA’s annual monitoring for defensible space or had not been updated with ember-proof vents—that is, they could have been saved.
Fire and Carbon Emissions
When we see huge clouds of smoke billowing up from the woods, we worry that wildfires release carbon dioxide and other greenhouse gases. Top science tells us the plumes are mostly harmless water vapor. Forest fires only release an average of 5-10% of the carbon in a forest, and unlike cars or other activities that release below-ground carbon, the forest is able to rapidly uptake carbon after a fire. The larger the tree diameter (old growth), the lower the percentage of wood lost from combustion. The older the forest, the more likely it will survive fire.
Fire and Air Quality
Even when fires are far away, citizens in both rural and urban areas sometimes have to deal with smoke carried on the wind. If the air quality is unhealthy, it is best to stay indoors or wear a filtration mask—especially for elderly people, children, or those with breathing problems. We provide shelters for people from floods, hurricanes, and other natural events, and we can retrofit buildings and schools to serve as smoke shelters for vulnerable people in our communities.
Top scientists tell us that older forests are the best buffers against climate change as they continue to add biomass (carbon) as they age. Fire and other natural disturbances do not cause a major loss in carbon from sites, if not followed by post-fire logging. Harvesting trees remains the major source of carbon loss in the Pacific Northwest, particularly on the west side of the Cascades. By requiring longer rotations and limiting clear-cutting of forests we can store more carbon in its forests. Thinning forests to reduce the chance of big fires on the west side of the Cascades is unlikely to be successful because climatic warming is likely to favor increased outbreaks of fire and it is impossible to thin and clear fuels away fast enough and broadly enough to have any major effect.
What it All Means
We like our forests because they are dynamic, wild, and not full of right angles. Fires themselves don’t hurt forests, cause climate change, or threaten water quality. Forests are constantly in a state of flux, storing and releasing carbon and oxygen. Young forests emerging from the charcoal are forests too, and valuable for plants and animals. We have millions and millions of acres that may burn, and we cannot thin our way to a fire-free future or prevent large fires from burning. We can, however, focus our attention and resources on our homes in the fire plain and in the immediate areas around those homes. We can also limit actions to increase our exposure to fires, by limiting new building to less fire-prone areas, increasing efforts to restore degraded forests, and further protecting water supplies—we can mitigate the impacts of climate change and increase our ability to coexist with fire.