It's now the accepted understanding that past aggressive fire prevention contributed to giant burns. There's a lot of substance to that, and letting smaller burns happen and even introducing some controlled burns are considered part of good management practices now.

This is not all that's going on, though, in the Sierras and elsewhere. Other contributing factors:

1) Drought. Severe drought. Trees need water. There's less of it.

2) The heat. Higher average temperatures (climate change!) affect how living trees use/need moisture and how dead trees turn to tinder.

3) Where these don't kill, they stress, and things like the current bark beetle infestation epidemic happen: http://www.huffingtonpost.com/brian-milne/pine-tree-deaths-p...

Fortunately, in the United States, we have several robust federal agencies dedicated to... wait. We massively cut funding to all of them years ago (http://wilderness.org/blog/sequestration-continues-threaten-... ). Largely under pressure of wild fantasies from the growing unhinged wing of the Republican party (which, let's hope, has reached its apotheosis in Trump) whose economics and governing philosophy are on par with their ability to recognize and admit science into a discussion of how we handle our environment.

So, yeah. Overprotection has been a problem. But prescribed burns have found their way into Forest Service philosophy (http://www.fs.fed.us/fire/management/rx.html ). And it's not going to solve the problem.

If only we were as able to let observant study and good stewardship guide us in other areas.