Editor’s note: This op-ed is by George Wuerthner, an ecologist and author of Wildfire: A Century of Failed Forest Policy and currently working on a book about energy and its impacts on upon the land, water, and climate.
There is an unfortunately a lot of misinformation coming from biomass boosters. Keep in mind that most of these boosters have a direct economic interest in promoting biomass.
Several points need to made about burning trees for biomass electrical generation. Because wood is less energy dense than other energy sources one must burn a lot more of it to get the same amount of power.
Burning trees releases a lot of participates that are a major health problem which is why many medical organizations have voiced opposition to biomass energy. While coal and other fuels also have health risks, we need to do full accounting of all costs before any major efforts are made to promote biomass and/or any other alternative energy sources so that we can measure the full risks of all energy sources.
Beyond the human health costs, there are real ecological costs associated with large scale biomass electrical generation.
Beyond the human health costs, there are real ecological costs associated with large scale biomass electrical generation. Burning trees for biomass energy releases significant amounts of CO2. While regrowth of trees will absorb some of this C02 over time, the problem is that this sequestration of carbon takes many decades, and perhaps hundreds of years. The problem is that we need to reduce C02 now, not a hundred years from now.
Proponents of biomass like to point out that a dead tree releases CO2 when it rots suggesting that releasing by burning is somehow no worse than what happens naturally. First as long as a tree is growing it is absorbing CO2 and larger trees sequential more CO2 than a young tree. Furthermore, when a tree rots this CO2 release occurs over decades. And the larger the trees, the longer it takes to rot, hence the longer that CO2 is out of the atmosphere. This timing of delayed CO2 release is an advantage we need in dealing with our climate challenges.
In addition, much CO2 is stored in the soil, both in tree roots, as well as among other soil components. The disturbance of soils that comes with logging operations, contributes to release of this stored CO2 as well.
Plus there is CO2 released by the transportation of wood to the point of burning. Since wood is a low density and widely distributed, the amount of fuel and carbon released in gathering wood adds even more to the total C02 emissions.
Finally, many of those promoting biomass electrical generation assume that logging the forest has few or little ecological impacts. But in fact, Vermont’s forests are already suffering from biological impoverishment from past logging. There are few old trees in Vermont’s forests. There are few snags and down logs on the ground and in streams. These physical structures are a biological legacy that contributes to functioning forest ecosystems. In essence the amount of logging that would be occur to make any significant contribution to energy supplies would quickly degrade forest ecosystems further.
Our best approach is to reduce overall energy use through efficiency and conservation, not by cutting down our forests. This is like burning the furniture and walls of our home to try to stay warm.
