This is my field of study and one of my professors was a park ranger at Saguaro. This is the result of failed fire suppression policies from the last 100 years.
Forests in places like Arizona and New Mexico are so incredibly overgrown that their basically a “tender box” (his words). They need to be burned, but it’s now at great risk. There are some places that need to be burned but can’t for this reason. They’re going to burn and cause massive damage one day, whether by government forces or by citizens
From the late 1800s to the late 1900s it was the policy of American land conservations to prevent fires at all costs. The problem is, fires have long been apart of the natural ecosystem. There are two big types of fires; brush fires and crown fires.
Brush fires are smaller and mostly burn away small bushes and saplings. Basically natural weed control.
Crown fires are much larger and much hotter. Most tree bark is fire resistant, so they’re immune to smaller fires. But without the smaller fires getting rid of the ground cover it leads to massive fires.
So in trying to stop brush fires lead to massive overgrowth of trees, bushes, etc. Now with all that extra growth it makes Crown fires, which were rare, much more common
TLDR; it’s from short sighted environmental policies
https://www.politifact.com/factchecks/2021/oct/15/heartland-institute/no-wildfires-werent-bigger-1920s-and-30s-today/That’s a politifact article that goes into it some
