Sunday, February 20, 2011 - Tacoma, WA
At first glance, it might seem that promoting the burning of wood to generate energy would harm the environment.
Indeed, the Thurston County Board of Commissioners recently adopted a moratorium on generating biomass power, and various groups have opposed biomass energy.
But these well-intentioned concerns are predicated on incomplete analysis that doesn’t withstand serious scrutiny.
Biomass, in fact, is a solar resource and need not have negative environmental consequences compared with fossil sources of energy.
Many believe that burning wood for energy has the same impact on carbon emissions as burning coal. But burning coal releases carbon that was trapped in rock and otherwise would have remained stored. This is not the case with biomass.
Trees absorb carbon from the atmosphere, reducing greenhouse gases. In sustainably managed forests, harvests do not exceed net new growth. The equal two-way flow of forest carbon means that the impact of harvest on atmospheric carbon is neutral, not 100 years in the future, but on an ongoing basis.
As forests age, tree mortality and decay increase. This limits the amount of carbon that can be stored in the forest.
By removing wood before the growth rate declines, forests can maintain a high rate of carbon removal from the atmosphere.
Biomass energy is produced by burning wood not suitable for building materials. Whether lower-value wood is burned for energy or left to decay, the carbon is ultimately recycled back into the atmosphere.
Leaving wood in the forest to decay results in the same quantity of emissions – without the benefit of using its energy value to reduce the one-way flow of fossil carbon into the atmosphere.
When forests are managed to remain carbon neutral, the sustainable harvest of products and biofuels displaces fossil-intensive materials and fuels, resulting in a net reduction of carbon emissions into the atmosphere.
Over the past decade, a consortium of scientists has conducted extensive research into the life-cycle greenhouse gas impacts of forest products and biofuels.
We found that for every megawatt of energy produced, biomass emits just 4 percent of the greenhouse gases of coal. It is also sustainable and domestic, contributing to energy independence that supports domestic economic activity and jobs.
However, because coal and other fossil fuels are cheap, companies will favor them over renewable sources if biomass emissions are penalized in the same way as fossil emissions. We have found that while using more wood in buildings has the highest leverage in reducing fossil fuel emissions, using waste wood as biofuels is also very effective.
We have also documented that managing federal lands to help control unnatural catastrophic wildlife results in lower greenhouse gas emissions.
By stifling biomass energy development, we can expect the fuel loads in our national forests to increase, more devastating fires, more greenhouse gas emissions, and the transition of some forests from a net sink for carbon storage to a net contributor to greenhouse gas emissions.
These unintended consequences are not consistent with America’s carbon mitigation objectives. They can only be resolved by a science-based understanding of the implications of proposed policies on the life cycles of all carbon pools.
This can provide a path to a cleaner energy future and put many Americans to work in green energy jobs by using wood as a renewable resource to absorb carbon from the atmosphere and displace fossil intensive emissions.
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Bruce Lippke is a professor emeritus and Elaine Oneil is a research scientist in the University of Washington School of Forest Resources in the College of the Environment.
Read more: http://www.thenewstribune.com/2011/02/20/v-lite/1552294/biomass-policy-can-have-unintended.html#ixzz1EXzygDEY
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