Unprecedented fires are occurring in the Canadian province of Quebec. According to the agency that protects forests in Quebec, Sopheu, an area of 6,400 km2 burnt. That is about one sixth of the Dutch land area and almost 500 times as much as the average in the last ten years – which is 13 km2. At least ten thousand people have been evacuated in the province. In almost all of Quebec is now banned to enter woods, and to light a fire in or near a wood.
Due to the smoke from the fires, the concentration of soot and particulate matter in the air has increased significantly over a large area. According to the American space agency NASA let that smoke show an exceptional pattern this time. Normally the wind blows to the east, and smoke blows out to sea. But this time, a low-pressure area around Prince Edward Island forces it southward. As a result, the concentration of particulate matter in the air above the cities of New York and Washington has risen to 175 micrograms per cubic meter (mg/m3), one of the highest values of the past 25 years. Something similar happened in 2002, even after fierce fires in Quebec.
Fires are not uncommon in Canada. It has extensive boreal forests, with characteristic species such as Norway spruce, pine, larch, where fires play an important role in the dynamics of the vegetation and of the animals that live there. Some coniferous trees need the heat of the fire to release their seeds. But ecologists are concerned that the fires are increasingly turning larger areas into ashes. Can ecosystems adapt fast enough to the current trend, which is largely caused by the changing climate?
Snow melts faster
The Arctic is warming three times as fast as the global average. Shrubs and trees can grow further and further north. The snow melts earlier and earlier in the spring, and falls later in the fall. In the far north, air currents are also more often seen that cause warm and dry weather, and lightning. Researchers from VU University Amsterdam showed in 2017 that lightning’s role in causing fires in the forests of Alaska and Canada had increased between 1975 and 2015, and is now the initiator of 75 to 95 percent of fires.
It is not certain that all these changes automatically lead to more fires. Humans play an important role in this. He can take measures to reduce the risk of fires.
On the website of the Canadian Wildland Fire Information System is a graph which shows the annual number of fires and the annual burned area from 1980 to 2021. The pattern is erratic, the values vary greatly from year to year. Broadly speaking, the annual number of fires is decreasing, but the annual burnt area appears to be increasing.
More fire from lightning
This is consistent with a study by Canadian scientists to fire trends over the period 1959-2018. In particular, they see the larger fires (more than 200 hectares of burnt surface) getting bigger and occurring more often. The fire season, which runs from the beginning of May to September, now starts a week earlier than in 1959 and also ends a week later. In addition, they see an increase in lightning-caused fires, and a decrease in human-caused fires.
Read about heat in western Canada in 2021: How could it reach 49.6 °C in Canada?
Rapid warming in the Arctic is breaking records. Two years ago, on June 29, the mercury in the town of Lytton, in western Canada, reached 49.6 degrees Celsius. The old record was pulverized by 5 degrees. The heat was followed by fierce fires, which reduced the village to ashes.
At the beginning of last month, fierce fires again occurred in western Canada. Exceptionally early, according to NASA.
Read an interview with geographer Sander Veraverbeke: Holes are appearing in the Siberian soil, and that worries scientists