This is some very interesting information about the current Canadian wildfires. I don’t know who Alex, the original author of the following is, because this came to me in a long email thread. #wildfires #Canada —————
Want to take a moment to address some of the most frequent questions we have seen in the comment section over the last few days. ❓Forest Management Neglect❓ To understand this question, you have to understand where these fires are burning. In green is an area known as the Canadian Boreal Forest. In the second image is the location of active fires across Canada. As you can see, most are burning within this region. Why is this important? This forest is massive—on a scale that most of us can’t begin to comprehend. It is the largest intact forest ecosystem on the planet. Additionally… 🌲 Canada’s boreal forest: ~1.3 billion acres (about 520 million hectares or 2 million square miles). It stretches from the Yukon to Newfoundland in an almost continuous belt. 🌲 Largest U.S. forest (Tongass National Forest, Alaska): 16.7 million acres. 🌲 Largest forest in the contiguous U.S. (Humboldt–Toiyabe National Forest): about 6.3 million acres. 🌲 All U.S. National Forests combined: about 193 million acres. For perspective… 🌲 Canada’s boreal forest is roughly 78 times larger than the Tongass, the largest forest in the United States. 🌲 It’s roughly 7 times larger than all 154 U.S. National Forests combined. 🌲 It represents one of the largest intact forest ecosystems left on Earth, with vast areas that have no roads and are inaccessible except by aircraft or winter roads. Less than 9% of Canada’s population lives within this region, and less than 1% of the boreal forest itself is developed. Most of the boreal is remote, roadless, and inaccessible, making large-scale forest management and wildfire suppression fundamentally different from managing forests near populated areas in the U.S. In ecosystems like the boreal forest, wildfire is one of nature’s primary management tools and has shaped these forests for thousands of years. While forest management absolutely has an important role near communities, roads, and other developed areas, applying that approach across more than a billion acres of largely roadless wilderness simply isn’t practical. ⸻ ❓Fires seem to be worse the last few years?❓ This is a bit of a tougher question to address because it has both truth and misconception tied to it. Canada has averaged roughly 7,000 wildfires annually over the last three decades. Interestingly, the 2023 season did not have an unprecedented number of fires—it had a near-average number of ignitions. With that said, 2023 was historically significant because of the total area burned. An unusually large number of fires escaped initial containment, grew exceptionally large, and produced one of the most memorable smoke events across the Northeast in modern history. ⸻ ❓Smoke seems to only impact the Northeast the last few years?❓ 💨 1950 – Smoke from major Canadian fires affected parts of the northeastern U.S., described in historical forestry and meteorological records. 💨 1988 – Smoke from widespread Canadian fires reached the Great Lakes and Northeast during a severe fire season. 💨 1995 – Canadian wildfire smoke produced hazy conditions and degraded air quality across parts of the Northeast. 💨 July 2002 – NOAA identifies this as the last smoke episode of similar magnitude to the June 2023 event in the eastern U.S. before 2023. 💨 2017 – Large British Columbia fires sent smoke across much of North America, with periodic impacts reaching the Northeast, though the strongest effects were farther west. 💨 2021 – Smoke from western Canadian fires reached the Northeast, producing hazy skies in several states. 💨 2023 – The record-breaking Quebec fires produced the most severe surface smoke event in decades for New York City and much of the Northeast. 💨 2025 – Another widespread smoke episode affected portions of the Northeast during Canada’s second-largest season by area burned. 💨 2026 – Smoke again spread into the Northeast, prompting air quality alerts from New England through the Mid-Atlantic. The short answer is yes—it has happened for decades. What appears to have changed is not that Canadian wildfire smoke suddenly began reaching the Northeast, but that surface-level smoke events affecting air quality have become more frequent over the last several years. A combination of larger fires and favorable upper-level wind patterns has allowed smoke to be transported and mixed down to the surface more often. It’s also important to remember that weather determines where the smoke goes—not where the fires are. The same Canadian fires can have little or no impact on the Northeast one year, then create hazardous air quality another year simply because of a different upper-level wind pattern. ⸻ ❓Doesn’t it smell like chemicals instead of smoke?❓ The answer is yes—and there’s a reason for that.
- Incomplete combustion (the biggest reason) Wildfires rarely burn cleanly. Smoldering logs, leaves, peat, duff, and damp vegetation burn at relatively low temperatures, producing: 👃 Aldehydes (such as formaldehyde and acrolein) 👃 Ketones 👃 Organic acids 👃 Phenols 👃 Benzene and other aromatic hydrocarbons Many of these compounds have a pungent, chemical odor even at very low concentrations.
- Different fuels create different smells A wildfire isn’t just burning tree trunks. It also burns: • Pine needles and resin (terpene-rich, sharp smell) • Leaves • Moss and lichens • Soil organic matter • Dead wood • Peat • Shrubs Each produces its own unique mix of volatile organic compounds (VOCs).
- Atmospheric “aging” As smoke travels hundreds or even thousands of miles—as Canadian smoke often does into the Northeast—the chemistry changes. Sunlight and ozone react with the original smoke compounds, producing new compounds that can make older smoke smell more chemical, acrid, or solvent-like than a nearby campfire.
- Sometimes man-made materials burn If fires involve cabins, vehicles, power infrastructure, or communities, smoke may also contain compounds from: • Plastics • Paints • Roofing materials • Synthetic fabrics • Electronics ❓Fire Ignition Source❓ ⚡️Lightning is overwhelmingly the dominant cause of the largest fires. Millions of lightning strikes every summer across the Boreal Forest, particularly during “dry thunderstorms”. Many strikes occur hundreds of miles from the nearest road or community. Some ignite immediately, while others become “holdover fires,” smoldering underground in peat or forest duff for days—or even weeks—before weather conditions allow them to flare up. Other Leading Causes (Small Percentage in these remote locations) 🔥 Campfires from hunters, anglers, and backcountry campers. 🚂 Sparks from railroads. ⚡ Powerline failures (where infrastructure exists). 🚜 Forestry and mining equipment. 🚗 Off-road vehicles and machinery. 🔥 Intentional arson (rare in the remote boreal compared to populated areas). This post isn’t intended to trigger debate, or to diminish other causal factors, but to provide some facts and perspective to the general conversation. 🤓 -Alex