Wild And Devastating Fires

Q: What starts wild fires? How can forests burn  just like that?

Krishna: There are some reasons for these wild fires. 

Summer season.  Climate change sparks prolonged droughts. Dried up bushes and plants, discarded/shed  leaves, broken and dead stem pieces and trees. Plus  extremely strong hot and dry winds that quickly spread flames in the drought-parched land. The winds often intensify as they are channeled through mountain passes and blasted across dry vegetation and steep surfaces to create perfect fire conditions. A perfect scene for wild fire incidents. 

 Some spread from scrap wood and tree branches set on fire at a home, while in some cases the most likely cause for the  hot particles from a power lines. Some are caused by smoldering debris left over from a controlled burn by forest service officials. Wind is one of the biggest factors in fire spread, and it also generates flying embers far ahead of the fire itself. It is this storm of burning embers that often shower neighborhoods and ignite homes after finding sensitive parts of landscaping and structures.

Under the worst circumstances, wind-driven home-to-home fire spread then occurs, causing risky, fast-moving “urban conflagrations” that can be difficult to stop and dangerous to evacuate.

Climate change is leading to conditions on the ground we have never encountered. Wildfires are increasing around the globe in frequency, severity and duration, heightening the need to understand the health effects of wildfire exposure. The risk of wildfires grows in extremely dry conditions, such as drought, heat waves and during high winds. Because now the summers are hotter than they once were, and droughts are more frequent. Scientists are warning that with man-made climate change,  the annual wildfire season will become even more drastic. 

These climatological shifts combine to turn forests into tinderboxes most summers, as a series of heatwaves and droughts in early summer dry out trees just months after the wettest winters on record. In fact, one research group estimates that half of the forest area burned in the past 30 years can be attributed to climate change.

Wildfires are a natural part of the lifecycle of arid forests: but today’s fires may be larger and more intense than in the recent past because of climate change.

The initial cause can vary—a spark from downed electric lines, a lightning strike or a cigarette butt tossed out a car window, a partially extinguished  fire used to cook outdoor meals, a campfire —but the result is the same: once vegetation dries out, it can easily ignite.

And finally arsons  - either by criminal negligence or by intention. 

With climate change leading to warmer temperatures and drier conditions and the increasing urbanization of rural areas, the fire season is starting earlier and ending later. Wildfire events are getting more extreme in terms of acres burned, duration and intensity, and they can disrupt transportation, communications, water supply, and power and gas services. 

The number and scale of wildfires around the world are increasing rapidly. Investment in forestry needs to increase to protect the world’s woodlands. Forest managers say they need more resources to protect and restore forests. We’re not only seeing ever-increasing fires year after year. We’re also seeing more fires over a larger geographical spread. And we’re also seeing a longer period. Our fire season used to be just two months of the year 15 years ago and now it’s nine months of the year.

Wildfire smoke is a mixture of hazardous air pollutants, such PM_2.5, NO₂, ozone, aromatic hydrocarbons, or lead. In addition to contaminating the air with toxic pollutants, wildfires also simultaneously impact the climate by releasing large quantities of carbon dioxide and other greenhouse gases into the atmosphere. 

Some of these wild fires are poisoning drinking water supplies too. Because pipes absorb a litany of chemicals from fires and firefighting, which leach into the water. Wildfire has become a serious public health and safety issue. Health effects from fires close to or in populated areas range from smoke exposure to drinking water contaminated by chemicals like benzene to limited options for the medically vulnerable. These kinds of threats are becoming major, statewide concerns.

Wild fires are no more wild. The reality is that fires are spreading into communities and increasingly affecting large numbers of cities, sometimes repeatedly.

Experts say, make no mistake, climate change is driving this dramatic increase in wildfires and future wildfire risk ... so, we can’t solve our wildfire crisis without addressing climate change.

Climate change will cause shifts in the atmospheric pressure patterns that spawn extreme wind events to begin with, and that in the future people may see extreme winds in new regions or during unexpected times of year. A deeper understanding of the controls on these events is emerging, but relatively little is known about what the future will hold.

Then the economic costs of these fires world wide. The price tag for all this? 2-3 Billions. And that’s just to contain the fires. Accounting for infrastructure damage and insurance payouts, a fire season will sometimes  leave taxpayers with a bill likely to top $30 billion!.

The barriers to protecting the world’s forests are entrenched and significant. It will need political will, commitment from forest communities and the right resources in the right places to make progress.

Managing the type and amount of vegetation, or “fuel,” in an area provides a set of tools for altering fire behavior and enhancing firefighter safety in wildland fires. But during wind-driven urban conflagrations, homes are usually a major – if not the main – source of fuel. Retrofitting homes to address vulnerabilities to fire ignition is therefore crucial.

One immediate strategy is for people to create so-called defensible space – removing flammable materials in the area surrounding homes. Vegetation management and prescribed burning in surrounding areas are also part of, but not the only, solutions. Fire-prone communities must also intensify urban and evacuation planning efforts that make the built environment – the buildings where people live and work and the infrastructure we depend on – and those living there safer.