Wildfires: Record Carbon Emission from Boreal Forests

publishing team This estimate March 2 in the journal science, based on satellite data. It’s too early to put together the 2022 fires, but already, this data confirms that the very large number of wildfires It happened in 2021 In northern Canada, Alaska and Siberia, it has had a noticeable impact. However, 20 years ago, temperatures were rising faster in the northern regions, the risk of heat waves was increasing, and with it the risk of fires.

In absolute numbers, this represents 0.48 billion tons of carbon released from boreal forests in 2021. This is two and a half times more than the annual average for the past two decades.

Admittedly, part of what is lost is recovered when the forest reclaims it: more trees means more carbon uptake. But it takes decades for the forest to regenerate, and in the meantime, humans will not stop emitting carbon dioxide. Not to mention the fact that the boreal forest is very slowly regenerating due to the cooler climate.

Speaking of burning forests, We tend to point fingers often In the Amazon, where these fires are the result of deliberate deforestation strategies, researchers acknowledge. “Northern Forests have received much less attention,” Although the Arctic is warming “Which is happening at a much higher rate than in the rest of the world.” So it is important to monitor what is happening there. As well as predictions of what awaits these forests if there are fires. As feared, it must continue to reproduce.

a task It has proven difficult over the years, because it is clear that satellite observations are more difficult through thick smoke. To overcome this hurdle, researchers from several countries, including China (three separate institutions were involved), France and the United States, compared levels of carbon monoxide emitted into the atmosphere in 2020 and 2021, during fires: Carbon monoxide (CO) , which is also released during fires, is a gas that is more easily detected by satellites than carbon dioxide (CO2), which made it possible to deduce the amount of carbon dioxide released.

This approach is not intended to replace estimates from calculations of burned areas, but it can help to enhance these estimates, as well as provide information on peaks in emissions when fire takes its toll.

Photo: Alaska fire of 2015. | Balinda O’Neill/US National Guard/Wiki Commons