There is limited causal relationship between temperature in a given yea
r and the number of severe fires. Long term, as the climate warms, no doubt there will be more fires in some places. California, Oregon, and Washington State have always gone through periodic drought years. It seems clear that the warming and drying trends are influenced by human activity (there are other factors, so the extent of the climate-change driven changes are not yet fully known) and that these trends, whatever the cause, are thus far making marginal increases in fire severity. Marginal.
The bigger, immediate problem is that many vegetation types in the “seasonally dry” parts of the west, in ecological terms, should function naturally with periodic, and generally low-intensity, forest fires. A long history of excluding those more-natural fires (over the past 100+ years) has led to a buildup of flammable materials, including grasses, brush, and in many places, trees. Millions of acres of our western forests now contain much more fuel (vegetation of various sizes and types, including trees) than they formerly had. When the expected, periodic droughts occur all it takes is a spark, and then large, catastrophic fires can happen.
What can be done about this? Some of those extra trees are large enough to be quite valuable. This means that they can be sold, and logged, at a profit; this is good news! Good news for taxpayers and our public officials, because timber sales can provide some revenue to offset part of the costs of maintaining public land. The cutting can be designed to remove a portion of the trees while retaining forest cover in most areas at most times. The cutting can be designed to enhance habitat for targeted wildlife species, while ensuring minimized risk to endangered species. On public lands this is the law. The harvesting activities and the wood from the harvests provides economic opportunities for rural communities. Wood from forests managed to remain as forests is an important part of a natural climate solution as well.
There are always tradeoffs. When harvests are intended to restore forests to fire-resilient conditions the work must include provisions for disposal of the branches of the trees that are cut. In some cases there can be a short term increase in fuel as the smaller branches and twigs dry out and before they decay or are disposed of. Loggers and foresters have done this work for many decades, so the workers, the skills, the knowledge and the equipment are available
When some of the excess larger and medium-size trees are sold for use to make forest products there often are requirements for most of the smaller excess trees and brush to be removed at the same time, resulting in less fuel. This makes it safer to reintroduce periodic, low-intensity ground fires. But if there are too many smaller trees and brush that also must be removed (at a cost) then even a commercial harvest (normally profitable) can be a net cost item.
Scientific studies and practical experience have proven that commercial harvesting of trees (thinning forests in ways that provide some income to the landowner) can provide dramatic benefits in many forested places. But commercial tree harvesting won’t help with grasslands or brushlands. In those places, and in some forests, the cutting, mowing and/or chipping that needs to be done before doing a prescribed (controlled) burn is expensive. Costs can be many hundreds of dollars per acre; there are millions of acres requiring such treatment. Long term, brush treatment followed by prescribed fire saves money and it saves lives, but it is expensive to do, and so not enough of it is getting done.
Summary: Our western forests need more funding, more freedom for thoughtful, practical use of the tool of commercial forest products harvesting, more prescribed fires, and time. This must be done on a large scale to restore our western forests to conditions where large, intense fires are rare, and most fires are safe, controllable, and not a major threat to property and human health.
This Washington Policy article provides some data to back this up.
This PBS news article provides more background information and statistics on wildfire in California.
Written by Mike Ferrucci, Interforest, LLC