Adapting to Wildfires in a Warming World

This June, historically severe Canadian wildfires caused millions in the eastern United States to head indoors. The Canadian disaster turned the skies in U.S. cities orange. Briefly, New York City had the worst air quality in the world.

With climate change driving ever more frequent, intense, and bigger wildfires—which firefighters struggle to control—Canada’s problems stretched to the United States, causing millions of Americans’ health to suffer. This current catastrophe should serve as a warning to prepare for the now unavoidable harms of climate change, including far-flung toxic smoke.

Few experts anticipated that Canada’s wildfires would rapidly become a U.S. problem. The first of the Canadian wildfires started in southwestern Nova Scotia at the end of May. It grew close to one hundred square miles, becoming the largest wildfire in that province’s history. Other fires soon followed in Nova Scotia, New Brunswick, Ontario, and Quebec. As of June 16, Canada had 2,467 wildfires burning. Canadian authorities anticipate this year will be the country’s worst wildfire season ever, with an area bigger than Massachusetts and Vermont combined already incinerated. Climate change honors no borders, and more smoke could well find its way south.

The Canadian wildfires are a sign of what is to come as climate change worsens wildfire risk: Climate change brings higher temperatures, and more heat means deeper drought and drier air. The same heat sucks moisture from vegetation, making it more flammable. Climate change has increased the intensity, speed, and size of wildfires. Bigger fires can carry their own extreme weather—creating “firenadoes,” funnels of smoke, flames, and wind that act like tornadoes.

Sixty-six thousand wildfires burned in the United States last year—seven thousand more than in 2021. The average length of the western United States’ wildfire season is now three months longer than it was decades ago. A recent study published in the Proceedings of the National Academy of Sciences determined that human-caused climate change drove a five-fold increase in area burned in northern and central California from 1996 to 2021. Additionally, burned area from fires has increased 172 percent more than it would have absent climate change’s effects.

Beyond acreage burned, wildfires pose dangerous health risks. The wildfire smoke from Canada carried microscopic particles, which can penetrate deep into the lungs and contribute to various respiratory and cardiovascular challenges. During wildfire events, hospitalizations and emergency room visits rise significantly. The carbon monoxide released from fires can reduce oxygen to the body and brain. Children are especially vulnerable to those health risks, as are pregnant women and those with existing heart and lung problems. Children exposed to smoke experience more coughing, wheezing, bronchitis, and colds. Even after the fires are controlled and the smoke is no longer visible on the ground, smoke particles can linger for weeks. With climate change increasing the frequency of wildfires, those particles persist for longer periods in the air.

When wildfires consume structures, the health risks rise even more. Consider Paradise, California, a town of about twenty-six thousand. In 2018, a wildfire incinerated Paradise in just a few hours, burning more than eighteen-thousand structures and killing eighty-five people. The incineration of cars, buildings, and infrastructure released chemicals—even radioactive isotopes—as everyday household items such as bottles of bleach and cleaners, paint cans, and batteries burned. Soil grew toxic. When the fires died, heavy metals and chemicals seeped into the town’s water supply. Inhalation or ingestion of those chemicals carry significant health risks, including respiratory and cardiac problems and cancer. The initial cleanup took months, but cleaning the water supply took years.

Wildfires and their smoke also come at an enormous financial cost. Between 2017 and 2021, U.S. wildfires caused more than $80 billion in damages. One study from the National Institute of Standards and Technology estimated the annual economic burden from wildfires—including wildfire management and all possible related costs—to be between $71.1 billion and $347.8 billion. This number, however, does not include lost economic activity, such as when fires prevent people from working outside, going shopping, or attending sports games and events. It also neglects hard-to-measure aspects of economic loss that recent studies are starting to make clear: One MIT study on air pollution and the labor market shows that each additional day of air pollution from wildfires results in earnings losses. Another study published in Nature found that exposure to wildfire smoke resulted in lower test scores for students and extrapolated future losses in earning potential for those exposed. And yet, wildfires are not included in any major models of the costs of climate change. This is a huge oversight, and suggests the United States is not prepared for the true economic burden ahead.

Further, wildfire risks are likely to worsen. A UN report found that climate change could lead to a 14 percent increase in wildfires in seven years and a 30 percent increase by 2050. Wildfires also create a vicious feedback loop by adding significant amounts of greenhouse gases into the atmosphere as they burn. This month, just before Canada’s wildfire problem became the United States’ wildfire problem, scientists flagged that global surface air temperatures temporarily spiked to 1.5° C (2.7° F) above preindustrial levels. The 2015 Paris climate agreement provides that to avoid the worst of climate change, average temperature increase needs to remain below 1.5° C.

The rapid reduction of greenhouse gas pollution is the first order of business to avoid the worst effects of climate change, including wildfires. A recent study in Earth’s Future found that controlled burns—smaller, intentionally set fires meant to reduce the threat of bigger conflagrations—in northern California and the Pacific Northwest could mitigate future smoke exposure. Communities and homeowners can further reduce wildfire risk by clearing out dried brush and investing in stronger building measures, such as those advocated by the Institute for Business and Home Safety. Land-use planners can avoid future damage by reducing development in areas likely to burn.

Artificial intelligence can allow authorities to detect wildfires earlier, which can help communities and homeowners prepare and respond accordingly. The creation of places safe from smoke—akin to cooling centers during periods of extreme heat—can provide public places for people to protect their lungs. Air filtration can reduce certain smoke pollutants indoors, decreasing the associated health risks. Unfortunately, changes to ventilation systems meant to reduce the risks of COVID-19 by circulating air from outside run counter to efforts to combat smoke pollution where the opposite is needed.

In 2013, the National Academy of Sciences warned that with climate change surprises are inevitable. Canada’s wildfire catastrophe becoming a U.S. catastrophe came as a surprise. More surprises will follow. When it comes to wildfires, communities and homeowners should prepare for bigger and more intense conflagrations, including those across U.S. borders.

This post was written for the Council on Foreign Relations’ Renewing America initiative—an effort established on the premise that for the United States to succeed, it must fortify the political, economic, and societal foundations fundamental to its national security and international influence. Renewing America evaluates nine critical domestic issues that shape the ability of the United States to navigate a demanding, competitive, and dangerous world. For more Renewing America resources, visit https://www.cfr.org/programs/renewing-america and follow the initiative on Twitter @RenewingAmerica.