The effectiveness of controlled burns debated as climate gets hotter and drier

The Australia wildfires has put the world´s focus on forest management and finding innovative ways to combat and prevent fires. One method often mentioned is Controlled Burns. However, some experts no longer believe in their effectiveness, reports the BBC.

Photo: (Above) Wildland Firefighter on Prescribed Burn, NPS Photo Michael Gue

Done properly, many believe controlled burns can help limit the spread of fires and make it easier to put them out.

But Swansea University professor Stefan Doerr, an expert in wildfires, believes the practice is less effective than it used to be because of the more extreme weather Australia has started to experience.

"It can make a difference for a few years, but I'm doubtful it would make a difference in the current extreme drought conditions," he said.

He adds:

"A particular problem of the recent fires in Australia is that they have spread across the crown or top part of the forest - so removing growth at ground level does not make that much difference. Also the fires have been hot and intense enough to burn through areas that were already burned, with embers able to travel through the air and ignite areas far away from an active fire."

The BBC article continues:

"As Australia battles unprecedented fires this year, a debate is under way about what is called "controlled burning" as a means to stop fires spreading.

Controlled burning involves deliberately starting fires under controlled conditions to clear out low-lying flammable material - sometimes called "prescribed" or "hazard reduction burning".

It is not the same as "back burning", which is done as a last resort to try to slow down an approaching wildfire by stripping the ground of vegetation."

Australian firefighters have a long history of carrying out this type of burning to reduce fire risk. "They are some of the most experienced and well-trained in the world," says Prof Doerr.

Burning to prevent fires is regulated and carried out by state agencies like the relevant fire service, park authority or environment body.

In areas of special environmental value or near heritage sites, national level permission is needed, according to the Department of the Environment and Energy.

An analysis by ABC News shows that while some controlled burning targets in Queensland and New South Wales have been met, others have not because the weather conditions were not right.

The NSW Rural Fire Service report for 2018-19 reveals that although they exceeded targets for reducing fire hazards in parks and forested areas, they fell short of their targets for local government land, privately-owned land and other areas.

Controlled burning can only be done in cooler, damper weather with low wind speeds, to avoid the fire getting out of control.

In 2015, a fire that was started by the Victoria state authorities to burn off hazardous undergrowth ran out of control, destroying four homes and more than 3,000 hectares of farmland and forest.

Rod Keenan, of the University of Melbourne, who has called for a more integrated approach to land management, says:

"A lot of resources have gone into extra fire trucks, hoses and getting volunteers. We're not putting sufficient resources into land management."