ST. LOUIS – Wildfires and smoke from Canada proved a persistent problem over the summer, not only in our region but across the northern plains, upper Midwest, and Northeast. The smoke created pretty sunsets aloft, but there are lasting effects that are not so welcome here.

In fact, some of these fires continue to burn in the permafrost through the winter under the snow. These are called zombie fires. And in the warmer months, these underground fires expand.

However, we can’t blame global warming on naturally-started wildfires. According to the National Park Service, humans are responsible for starting 85% to 90% of wildfires.

Nonetheless, the emissions of greenhouse CO2 gases from wildfires and burning fossil fuels are key components of the global temperature balance. But there are other natural contributors to global warming.