Canada’s 2023 wildfires outsmoked global aviation, yet emissions go uncounted

On a June day in 2023, New Yorkers woke up to an eerie scene: the sky had turned a murky orange, the sun a dim red orb in the haze. The culprit? Smoke from wildfires hundreds of miles away, in Canada. This surreal tableau, once a rarity, has become increasingly common as North America grapples with more frequent and intense wildfires.

A new report by researchers from the Global Forest Watch initiative at the World Resources Institute and the University of Maryland reveals the massive scale of Canada’s 2023 wildfires.

The fires scorched approximately 7.8 million hectares (19.3 million acres) of forests in Canada last year, an area nearly the size of Ireland.

First Nations communities were particularly hard hit by the 2023 wildfires. More than 42% of wildfire evacuations in 2023 were from communities that are more than half Indigenous.

All this burning produced roughly 3 billion metric tons of carbon dioxide emissions, according to the report, almost four times more than the global aviation sector in the same year.

“[Emissions were] six times the average for the last 20-plus years,” James MacCarthy, a research associate at Global Forest Watch and one of the report’s authors, told Mongabay. “It’s astonishing just how much more we’ve seen in recent years.”

To put this in perspective, these emissions are equivalent to the annual output of about 652 million typical passenger vehicles. It’s as if half of the world’s entire fleet of cars suddenly doubled their driving for a year.

Unlike cars, trees can grow back and recapture some of that carbon, but this can take decades, and as fires become more frequent, permanent carbon recapture isn’t certain. “Meanwhile, time is in short supply to prevent irreversible damage from climate change,” the report states.

Climate change: Fueling the fires

The climate crisis appears to be driving this trend toward more extreme fire seasons. Higher temperatures caused by climate change dry out the landscape and make forests more susceptible to fire. The researchers point out that Canada and other northern regions are warming up about twice as fast as the rest of the world.

At the same time, rainfall has become more variable in other areas. More rain means more vegetation. When the droughts come, the extra vegetation becomes more fuel for the fire.

“We’re seeing a clear trend of fire seasons getting longer and more severe,” Alexandra Tyukavina, a fire data expert at the University of Maryland who contributed to the analysis, told Mongabay. “What used to be considered extreme fire years are becoming more common.”

The report also warns about a dangerous cycle: climate change leads to more fires, which release more carbon, contributing to further climate change.

“Climate change is resulting in warmer temperatures. It’s making rainfall more variable in some areas, and so this can result in drying out the forest and making them more susceptible to fires,” MacCarthy said. “Larger fires release more carbon dioxide because more trees burn that store the carbon. That goes into the atmosphere, where it contributes to more climate change.”

Wildfires: The carbon accounting conundrum

Despite Canada’s massive wildfires in 2023, most of the emissions from those fires won’t show up in official U.N. reports.

The UN reports in question are part of the United Nations Framework Convention on Climate Change (UNFCCC) reporting system. Each year, countries that are party to the UNFCCC submit national greenhouse gas inventories, detailing their anthropogenic (human-caused) emissions by sources and removals by sinks. These inventories are crucial for tracking global progress in reducing emissions and meeting climate goals set by international agreements like the Paris Agreement.

Historically, fires are a naturally occurring phenomenon in many Canadian forests. But the line between natural and human-caused fires is getting blurry. About half of Canada’s fires are started by people, and climate change (also caused by humans) is making fire seasons longer.

This creates a problem for tracking greenhouse gases. Canada is unique from most countries in that it doesn’t count wildfire emissions from managed lands in its official numbers, ostensibly so it can focus more directly on human-caused sources of emissions like logging.

“By excluding all emissions and removals in managed forests affected by natural disturbances, Canada’s national greenhouse gas inventory may be underestimating land-based carbon emissions,” the researchers write.

As climate change worsens fires, the researchers say this accounting approach might need to change. Even U.N. reviewers have questioned whether it’s right to assume all wildfire emissions are non-human-caused.

“With climate change expected to increase annual burned area by 30-50% globally by the end of the century…correctly accounting for them in global emissions inventories is essential,” the report states. “Fighting forest fires — and accurately accounting for their emissions — are critical measures for overcoming the world’s growing climate crisis.”

Health impacts

Not all fires are bad; many ecosystems depend on periodic burns. But the increasing frequency and severity of wildfires driven by climate change pose real dangers.

According to a recent paper in the Canadian Medical Association Journal, wildfire smoke can be more toxic than other types of air pollution. The fine particulates can travel more than 1,000 kilometers (600 miles), enter the body, generate free radicals, and cause inflammation in body organs that worsen a variety of health issues.

The health impacts of these increasingly severe wildfire seasons are a growing concern, according to Mehdi Aloosh, assistant professor at McMaster University and medical officer of health of Windsor-Essex county, Ontario. “As climate change causes more frequent and severe wildfires, wildfire smoke becomes a larger health problem.”

Individuals can reduce health risks by taking steps like staying informed about local air quality, using air filters at home, and wearing appropriate masks when air quality is poor.

Looking ahead: Solutions and hope

Despite these grim realities, experts emphasize that all is not lost. MacCarthy and Tyukavina stressed the importance of maintaining hope and focusing on solutions.

“The biggest recommendation is that we need to drastically reduce carbon emissions from a variety of sectors,” MacCarthy said. “Climate change is the primary driver behind the increase in large forest fires in Canada, and we need to act now.”

Working with First Nations and Indigenous peoples to reintroduce controlled burns to their lands is also an important strategy moving forward, MacCarthy noted. For generations, many Indigenous peoples used controlled burns to clear undergrowth and reduce fire severity. However, colonial fire management policies largely suppressed these practices.

Educating people about fire safety, involving communities in planning how to protect homes and towns, rebuilding after fires in safer ways, improving forest management, and leveraging technology to better predict fire risks are all solutions that can improve people’s experiences of fire in what some are calling “the pyrocene.”

“We’re all downwind. We are all connected. It’s not just a California problem; it’s not just a Canada problem,” John Vaillant, a journalist who has reported extensively on wildfires, told New York Magazine last year. “We really are going to go through this impending future together.”

Banner image of 2020 boreal fires courtesy of Greenpeace International.

Liz Kimbrough is a staff writer for Mongabay and holds a Ph.D. in Ecology and Evolutionary Biology from Tulane University, where she studied the microbiomes of trees. View more of her reporting here.

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Citations:

MacCarthy, J., Tyukavina, A., Weisse, M. J., Harris, N., & Glen, E. (2024). Extreme wildfires in Canada and their contribution to global loss in tree cover and carbon emissions in 2023. Global Change Biology. https://doi.org/10.1111/gcb.17392

MacCarthy, J., Tyukavina, A., Weisse, M., & Harris, N. (2024, June 27). Canada’s Record-breaking 2023 Wildfires Released Nearly 4 Times More Carbon than Global Aviation. World Resources Institute. https://www.wri.org/insights/canada-wildfire-emissions

Ghodsi, E., & Aloosh, M. (2024). Wildfire smoke. Canadian Medical Association Journal, 196(23), E789. doi:10.1503/cmaj.240135

The burning challenge: Seeking a sustainable path for people and fire. (2024). One Earth, 7(6), 925-926. doi:10.1016/j.oneear.2024.06.001

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