There seems to be a misunderstanding in what is often referred to loosely as wildfire risk. Risk for anything is calculated by combining the probability or chance that an event occurs and the consequence of that event occurring. We do things to manage risk that can change either the chance that the event occurs, the consequence of the event occurring, or both. The COVID-19 vaccine is a perfect example of changing both, by decreasing the chance that you get COVID-19 and the consequence if you do (decreased severe illness).
In wildfire terms, I keep seeing news stories and quotes from elected leaders that forest management is going to reduce wildfire risk or, in the most poor representation of the concept, treatments will stop wildfires. In terms of the risk equation, the chance that a wildfire occurs is the result of having an ignition source when the vegetation and weather will support that ignition turning into a fire. The consequence of the fire depends on how and where the fire burns. We have no shortage of ignitions on our flammable landscapes in the US. This year, in the western US, we have severe drought conditions that mean there is a greater chance that an ignition will cause vegetation to combust because dry vegetation is more flammable than wet vegetation. What we really care about though is the consequence of a wildfire occurring and this is where forest and vegetation management come into play. As I have written about before (here and here), when you have more vegetation and it becomes drier, fires can become more impactful because they are releasing substantial amounts of energy that can lead to things like a fire creating its own weather. Managing vegetation reduces the chance that a fire creates its own weather because there is less energy stored in vegetation. Managing vegetation also helps create conditions that allow wildland firefighters to more easily protect homes and it changes the effects of the fire on the vegetation that is present on the landscape. The basic fact is that we cannot exclude fire from our landscapes. We have plenty of ignitions and climate change is making the vegetation more flammable. We also have a surplus of vegetation in a number of areas because we have been excluding fire for decades. We are trying to change the risk with forest management by changing the way the fire burns on the landscape. We also need to work on making homes less flammable and managing vegetation in the wildland urban interface to help reduce risk, but that is a topic for another day. When you hear or read about reducing wildfire risk, this is really about changing the way that fire behaves on the landscape. When you hear someone talk about forest management stopping fire, know that is incorrect and we cannot stop fire. Managing vegetation to change fire behavior is one of the solutions that we have at the local level for managing the risk of high-consequence wildfires.
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