Usually, wildfire season in the United States and Canada is in the middle of summer. However, exceptionally dry conditions in Canada have allowed fires to burn out of control, with very little rain in sight.
The smoke caused by those fires has proven especially impactful for the Midwest, thanks in part to the polar jet stream that is usually traveling through Canada and The Great Lakes quite frequently.
According to NASA, wildfires across the world are getting worse. There has been a clear increase in size, number and intensity worldwide. In addition, the number of acres burned has increased through the years. The most likely cause for the steady trend is an average increase in global temperature, which leads to an increase in extremes, like extreme drought and extreme flooding.
According to the EPA, the number of fires in the U.S. increased from the 80s to the 90s but has stayed fairly consistent since then. However, the number of acres burned has steadily increased over the decades in the U.S.
It is important to note that wildfire numbers typically fluctuate from year to year. For example, in the previous two years, wildfire smoke that found its way to the Midwest and eastern portions of the country was predominately from fires in the United States. The Western U.S. had been experiencing extreme drought and unprecedented fires in many locations. This year, heavy rains out west will help to mitigate the problem for the summer season of 2023.
At first glance, the extreme rain and snow events may seem like only a benefit to the moisture-starved Western U.S. Unfortunately, there is a bit of a catch. Very wet years often lead to a surplus of new brush fuel. Plants expand and thrive off of the extra moisture. But if the moisture was provided by an extreme event, like the rain and snow in California this year, the plants usually cannot survive. In the wake of a wet year, a “normal” year leads to excess fuel.
While drought is not rare in the western U.S., extreme drought has become more common over the last few decades. This means the rain and snow surplus we received out west will lead to a beautiful short-term benefit but will need to be watched as a potential factor that could worsen future fire seasons.
It’s also important to note that there are multiple complicated reasons why fires are becoming more severe, according to Benjamin Cook, a climate scientist with the NASA Goddard Institute for Space Studies, who spoke with NewsNation last summer.