These escalating fires are apparently called “zombie fires”. A team of Dutch and American researchers wrote this week that now that the region’s summers are warmer and drier, it is more common. nature.
Most forest fires are started – intentionally or otherwise – by people or lightning strikes. This does not apply to zombie fires, they simply never go out. The carbon-rich peat soils of the tundra allow the fire to catch fire in the ground all winter, then ignite again when the snow melts.
Winter fires usually make up a small portion of the total, being on average responsible for less than one percent of the total burned forest area in an area. But there are extreme values: in 2008 the share had risen to 38 percent. “This is at the expense of nature, and it causes air pollution and causes additional emissions of greenhouse gases,” says climate scientist Rebecca Schulten from VU University in Amsterdam. nature. “Not only from above-ground vegetation, but also from the peat soils itself.”
The travel speed is up to 3 cm per hour
Researchers combined data from conservationists with satellite imagery to map zombie fires in recent years and determine where and when they were most common. They write that the underground travel speed of a burning fire ranges from 1 to 3 centimeters per hour. Therefore, new fires cannot be expected at a distance of no more than 300 meters from the burning areas of the previous year. Usually, fires re-ignite within weeks of melting, especially in years after a hot and dry summer with many fires. This will increase due to climate change. It is precisely in this northern part of the world that the warming is increasing above average.
“Since the number of wildfires last year wasn’t too bad, we don’t expect many zombie fires in these areas in the next year,” says Schulten. “But the first has already appeared in Siberia.” It was very hot last summer and there were many forest fires.
Forest ecologist Mart-Jan Schelhaas of Wageningen University & Research, who was not involved in the research, found the results closely related. “Zombie fires are still a marginal phenomenon, but this research makes it plausible that we will have to deal with it more and more.” The possibility of an entire winter underground catching fire for an entire winter is a fairly new idea, says Schelhas, but we often see that peat soil makes firefighting more difficult. “Also in the Netherlands, like last year in the Belle More area around Durn.” This blaze set fire to 900 hectares of forest and spread over the ground and underground. Firefighters had to put out the flames for weeks.