Canada's 2023 wildfires released more carbon than many nations.

In 2023, Canada experienced its most devastating wildfires on record, with the burned area comparable to the size of Florida.

A recent study published in the journal *Nature* reveals that last year's record-breaking wildfires in Canada generated more carbon emissions than fossil fuel combustion in nearly every country except China, the United States, and India. The fires, which were fueled by extreme heat and drought conditions, devastated approximately 15 million hectares (37 million acres) of land—an area comparable to the size of Florida. This wildfire season was the most severe in Canada's history, and scientists are increasingly concerned about its implications for global climate change projections. The boreal timberlands in Canada play a pivotal part in sequestering carbon, and the phenomenal burning may essentially affect worldwide carbon levels. The study, conducted by researchers from the California Institute of Technology and several universities in Canada, the Netherlands, and Missouri, estimated the total carbon emissions from the fires at approximately 647 teragrams (one teragram equals one million metric tons). This amount is substantially higher than the usual emissions from Canadian wildfires, which have ranged from about 29 to 82 teragrams of carbon annually over the past decade. To put this in perspective, the emissions from these fires were five times greater than Canada's total annual carbon output and nearly on par with India's 740 teragrams of carbon emissions last year. Brendan Byrne, a carbon cycle scientist at NASA’s Jet Propulsion Laboratory and one of the study’s authors, described these findings as “shocking,” adding that there is increasing concern that such massive wildfires could become more common in Canada, further affecting the global carbon balance.

The increasing severity of wildfires in Canada.

Wildfires during the summer months are common in Canada’s boreal forests—northern regions dominated by deciduous trees and conifers. However, scientists have observed that these wildfires have become more frequent and intense in recent years. In 2023, Canada endured its hottest and driest summer since 1980, leading to the worst wildfire season in the nation’s history, with fires raging across the country. Although most of the fires were extinguished by fall, a record number continued to smolder beneath thick layers of snow through the winter. While the current wildfire season has been less severe than the previous one, it is still on track to produce the second-highest carbon emissions from wildfires in Canada since 2003, according to August data from the European Union’s space program. These projected emissions are second only to those from the devastating fires of last year. Predicting future wildfire activity remains challenging, but according to Mr. Byrne, the hot and dry conditions that fueled Canada’s record-breaking wildfire season could become the norm by the 2050s. Additional studies also suggest that as temperatures continue to rise, wildfires in Canada may become more frequent and intense.

How the wildfires in Canada could influence future climate predictions.

Researchers are sounding the alarm over the long-term implications of increasing wildfire activity in Canada. The country’s forests, which constitute 8.5% of the Earth's total forested area, play a crucial role in sequestering carbon dioxide from the atmosphere, thereby mitigating global warming. However, recent studies indicate that Canada’s boreal forests are burning at a rate faster than they can regenerate. Co-author of the study, Mr. Byrne, explained that this trend could significantly diminish the forests' capacity to store carbon, leading to higher levels of carbon dioxide in the atmosphere than previously anticipated. This potential reduction in carbon sequestration forces scientists to reconsider the amount of carbon that can be emitted without pushing global temperatures beyond a manageable threshold. Mr. Byrne further emphasized that future planning currently assumes these forests will continue to absorb carbon. However, this assumption might need revision in light of the increased fire activity. The 2015 Paris Agreement aims to limit global warming to 1.5°C (2.7°F) above pre-industrial levels, yet last year was recorded as the warmest since 1850, according to the European Union’s Copernicus Climate Change Service. Canada is already experiencing the effects of climate change, with the country warming at a rate twice the global average due to its vast land area. The Arctic region is heating up at a rate that is three times faster than the global average. Last summer, Canada experienced temperatures over 2.2°C (4°F) higher than the historical norm.