At the time of writing these lines there Canada has 1,052 active fires, 852 of which are still out of control. But if records are kept from January of this year, the total number of fires is closer to 6,000. Something that has led to tens of thousands of evacuations and the loss of 15.2 million hectares (an area equivalent to half of Italy). Figures that have already helped wipe out the previous national record (7.3 million hectares burned in 1989), but four months before the end of the year, all indications are that they will continue to deteriorate.

The situation in the world’s second largest country is dramatic, despite attempts by the authorities to bring the fires under control. But the entire planet suffers from the consequences. The smoke from the fires completely darkened cities like New York and even reached Spain after traveling over 7,000 kilometers (an unusual event). In addition, emissions have risen sharply, which could affect the ozone layer. And the burnt vegetation will no longer be able to act as a carbon sink.

Marcelino Nunez, Aemet’s spokesman in Extremadura, notes that carbon emissions from wildfires in Canada had already exceeded 300 megatons of CO2 in early August. about three times the average fire season in recent decades. But since then, they have continued to increase: the latest data from Copernicus, the European Union’s Earth Observation Program, suggests that 377 megatons have already been reached.

“The scale of fires in Canada in 2023 andThis is the largest reported case in this country. But, unfortunately, in previous years and at the planetary level, there have been other similar episodes in other countries, such as the fires in Siberia in 2016, in Chile in 2017, and those that occur every year in the sub-Saharan region. Africa, where recent studies show that about 70% of the burned surface worldwide is burned there,” Nunes says. And he adds: “Fires are a phenomenon that occurs on a planetary scale and every year is becoming more widespread. and intensity.”

Reasons for a record year in Canada

Nunez explains that the recipe for a big wildfire you only need three ingredients: vegetation serving as fuel; fire caused by human activity (intentionally or unintentionally) or natural phenomena and meteorological conditions that cause hot, dry and windy weather. And in the North American country, all three things were fulfilled.

“Many fires in Canada are occurring where conditions were much drier and hotter than usual. This results in a higher flammability of the fuel, meaning that the vegetation is in an ideal state to ignite when ignited. And the increased danger of fires means not only an increase in the risk of their occurrence, but also the fact that the scale and intensity of the fire can be much larger”, – says in detail Mark Parrington, Copernican scholar.

In the spring, Nunez says, high temperatures kicked off the fire season. in Canada it started earlier than usual and very intensively. In mid-May, a heat wave in the provinces of British Columbia and Alberta exacerbated the effects of the first fires. In June, the same thing happened in Quebec, at the height of another record heat wave. And in July, which was the hottest month ever recorded on the planet, some of the world’s most “anomalous” temperatures were found in northern Canada.

“The main fires have occurred in the Northwest Territories, including Yellowknife, the provincial capital and largest city. In addition, major fires have occurred in Alberta, British Columbia, Nova Scotia and Quebec. By the beginning of June, many acres were already burning there, which in Canada are usually burned for the whole season, but by the beginning of August scorched earth was about twice normal”, – says the expert Aemet.

If we study the causes, we will inevitably have to talk about climate change. And the fact is that although fires need favorable weather, global warming provides them with ideal conditions so, like in Canada, they are more assertive. Parrington explains: “Climate change is creating drier and hotter conditions that increase the risk of flammability and fire. Our analysis showed that the majority of observed fires occur when soil moisture is much higher than average.”

Impact on the ozone layer

The scientist Copernicus details that in 2016, a series of fires occurred in Canada, caused by the high energy of the fire. emit smoke into the upper atmosphere. A phenomenon that may have consequences for the ozone layer. However, he believes that the same will not happen with the fires this year, because “it does not look like there was a lot of smoke emission directly into the stratosphere.”

However, Nunez notes that recent research points to the hypothesis that particles emitted by wildfires interact in the “extremely complex atmospheric chemistry” of the ozone balance. “It appears that forest fire smoke particles interact with stable chlorine compounds in the atmosphere, and as a result processes of destruction of the ozone layer are generated “assures.

As specified, thanks to the Montreal Protocol of 1987, which regulates the production and consumption of the famous CFCs, highly destructive compounds of stratospheric ozone, the ozone layer is recovering. The UN estimates that the full recovery of the ozone hole is expected by about 2066 in Antarctica and by 2045 in the Arctic. But with these new discoveries, researchers are concerned that an increase in wildfires could jeopardize this progress in the regeneration of this layer, “necessary for life on the planet.”

Vegetation as a carbon sink

The example of Canada serves to illustrate another problem. When forests burn, they release large amounts of stored carbon. But when the vegetation in the burnt areas grows back, it pulls that carbon out of the atmosphere. A process that is part of a normal cycle emissions and recovery of CO2 from fires that, however, it is changing.

“In recent years, what has been happening is that climate change, caused by excess CO2 in the atmosphere, is giving rise to extreme situations of drought and very high temperatures, which favor the intensity and frequency of fires. What upsets this balance,” explains Nunez, who elaborates that now this process has a feedback: “The more fires on the planet, the more CO2 emissions, and these return to creating conditions conducive to other fires. It’s a vicious circle that needs to be broken.”