Forest Thinning: A New Environmental Debate

The origin of the Problem:

The 2002 fire season was severe:

It cost an estimated $1.6 billion to suppress wildfires in 2002, and nearly $1 billion had to be shifted from other forest programs such as thinning to contain the blazes. The Forest Service and the Interior have an $800 million fire suppression budget this year.

The Current Situation

Current Active Fire Maps

GEOMAC (a very good interface leveraging the internet)

2003 Fire Season Outlook:

The situation in March 2003 seemed quite dire but strong snowstorms throughout the West in April mitigate the problem a bit.

Nevertheless, the outlook for the American West is not good:

And the streamflow forecast looks dire:

Current Fire Danger Threat (but its only June!)

The United States has 190 million acres of land that needs to be thinned, according to the Forest Service. Fuels build up is critical.

But thinning is very controversial

The situation for Western Washington. Number of fires has increased in the 90's, number of acrs burned has not.

Clearly the American West has a looming problem and now there is a controversial plan of action to aggressively thin forests to counter decades of fuels build up.

Run the Forest Fire Simulator

This is a significant build up of fuels!

Forest Thinning, Physics and Policy


  1. What is the range of tree diameters that should be taken out (small ones only, big ones only, some range?). This depends a lot on the nature of the particular forest (Ponderosa Pine vs. Douglas Fir, etc)

  2. Lack of trust is a real problem. Many see "forest thining" as a Trojan Horse, masquerading another agenda, that of more aggressive logging. We luv conspiracy theory ...

  3. An interesting evironmental dilemma involving endangered species may occur in conjunction with forest thinning. Who wins?

  4. What is the procedure for thinning forests?

    • Surgical Helicopter logging or balloon logging. This is very effective but too expensive.

    • Infrastructure traditional way, build roads, bring in bulldozers and other equipment. Can provide for lots of jobs, but is not environmentally benign.

    • Old methods Mules, horses and workers. All manual may be the most inexpensive way to do this.

    A still overriding concern is who pays for all of this (and the total price tag could be high). Looking at if from the bean counting point of view it may actually be cheaper to just deal with the forest fires than actually do the necessary thinning of 190 million acres.

    Whatever the result, your likely to see a lot of protest and attempts to block various thinning projects. Some of those will be legitimate, some of those will be based on the NIMFBY problem. Its an excellent example of policy being set in a data vacuum.

    Finally, to be clear. All that forest thinning really does is to minimize the probability of catastrophic fire storms. This is an important objective. Thinning, by itself, will not prevent forest fires.

    Additionally, thinning should promote greater diversity on the forest floor but its unclear if the soil nutrient base is sufficient to support this.