Regardless of which hemisphere you live in, you’re likely to see year-round headlines announcing wildfires — in places like Europe, Canada and California — describing loss of life, property and habitat. The latest bushfires raging across Australia show a worrying pattern; forest fire season is earlier, longer and more intense. But why, and what is changing forest fire origin? How does a natural wildfire start and what are countries doing to prevent these disasters from happening?
Australian Bush Fires
Between December 2019 and the end of January 2020, bushfires burned more than 27.2 million acres (11 million hectares) in Australia, destroying more than 2,000 homes and resulting in 33 deaths. The BBC reported that authorities in New South Wales, the worst-hit state, ordered a state of emergency in areas south of Canberra.
NASA satellite imagery in another BBC article showed smoke from the bushfires extending over the Pacific, reaching as far as South America. Vast tracts of land are burned, with fire destroying natural habitat and killing livestock and wildlife in its path. As with fires burning in the Amazon, loss of habitat seriously threatens diversity in the area as well as releasing abundant carbon stores locked up in the vegetation. The impact of this year’s bushfires is not yet known, but Australia and other countries with high fire risk fund research into forest fire origin to develop prevention and protection strategies.
How Does a Natural Wildfire Start?
In most cases, natural wildfires start with a lightning strike; these go unnoticed in unpopulated areas and usually burn themselves out. The Canadian province of British Columbia estimates that lightning strikes account for approximately 60% of forest fires annually. Enough heat is released to set fire to trees and underbrush. Prolonged drought, insect infestation and increased temperatures create more dead and desiccated vegetation as fuel, and fires take hold more easily. According to CNN, high temperatures combined with high winds drove the Australian bushfires.
However, in areas with urban interfaces where people, agriculture and property sit close to forest fuel, human causes also factor in. These include accidental ignition from using engines in dry grassland, discarding cigarette butts and campfires, but authorities also cope with deliberate acts of arson.
Set Fire to Prevent Fire
In answering the question — how does a natural wildfire start? — countries can use the information to develop strategies that both prevent and fight this hazard.
Forest fire origin needs heat, oxygen and fuel for success; removing one of these quenches the fire and prevents spread. Climate change predicts increasing temperatures with longer drought periods that will affect two of these factors, so efforts that reduce fuel and create firebreaks are key.
The Conversation notes that preparation is as important as response and recovery in managing wildfires. Removing underbrush mechanically, thinning forests and using prescribed burns all reduce fuel ahead of fire season.
But without understanding the land and its vegetation, uncontrolled burning could set up worse conditions for the future. For this reason, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia is working closely with aboriginal knowledge holders to manage ecological niches. Managing and timing these burns encourages vegetation growth that supports habitat diversity and reduces future fire risk. Time describes how traditional ecological knowledge brings a new awareness of the seasons. Based on local animal activity, this close understanding of the land means that prescribed burning takes place as needed by each microregion rather than according to the calendar. This promotes growth of less flammable native vegetation rather than invasive species, which often burn more readily.
Building Fire-Resilient Communities
In terms of developing response strategies for managing wildfires, countries are also going high-tech to fight these fires. Research into vegetation mapping, remote surveillance by drone and satellite, and data sharing initiatives help crews on the ground.
However, climate change isn’t going away, so taking action to mitigate fires is crucial. For example, the United States Forest Service suggests that communities take responsibility to identify fire risks and create solutions for them by creating resilient structures and landscapes. These actions can help people live safely in the Wildland-Urban Interface.
Resilient landscapes are only part of the solution. Ensuring reduced fuel, thinned forest and mechanically created firebreaks around habitations helps stop buildings burning and maintains safe evacuation routes, says the United States Forest Service.
There are also steps homeowners and developers can take. Many municipal governments now include forest fire mitigation as part of city planning. The Resort Municipality of Whistler runs a Fire Smart program with property guidelines and services. This advises homeowners to reduce flammable vegetation through choosing fire-resistant planting and keep fuel away from outer walls.
The U.S. Forestry Services advises making buildings more resistant to airborne embers by using materials with low flammability. For example, cedar shake roofing or sidings catch fire easily, and metal spark screens under eaves and deck space will stop embers.
Understanding forest fire origin and a little DIY could help save your home.