The Woody Biomass for Energy Debate- Manomet Study

As I watch the climate debate, I’ve noticed that biomass has a bad rep in some climate circles. Sometimes it is as simple as biomass is ethanol ethanol is bad therefore biomass is bad. Sometimes it is more nuanced. Seldom is it discussed in a way that reflects differences among places and the variety of possible technologies and material to be used.

Last weekend there was an article in the NY Times on a Manomet study. In this Q&A, John Hagan and Thomas Walker go into some depth describing their findings. Here are some considerations:

The framework we developed for carbon accounting could be used for an individual power facility, a state, a country, or even the European Union (which is importing wood chips from the U.S. and other countries to meet its renewable-energy goals). In order to assess the greenhouse gas implications of using wood for energy, you have to know four things:

• The life cycle of the wood (e.g., logging debris, whole trees, trees vulnerable to catastrophic events) in the absence of the biomass energy opportunity.

• The type of energy that will be generated (heat, electricity, combined heat and electricity), because different types have different efficiencies and thus different CO2 emissions profiles.

• The type of fossil fuel being displaced (coal, oil, or natural gas), because different fuels have different emissions profiles.

• The management of the forest — management can either slow or accelerate forest growth, and therefore recovery of carbon from the atmosphere.

To further complicate the story, while our life cycle analysis looked at greenhouse gas emissions from production and transport of both biomass and fossil fuels, we couldn’t evaluate every possible environmental impact of energy production, such as broken blowout preventers 5,000 feet under water or mountaintop removals to access coal. Rarely (maybe never) does society really weigh the full array of costs and benefits of our decisions. But as the world gets more complicated, and as resources get more scarce, and as the human population climbs to nine billion (and then some), we’re going to have to become more serious about analyzing these kinds of trade-offs.


But our study suggests that it’s important to be specific about how you define biomass. Energy generation from harvests of live whole trees from natural forests has different life cycle implications than energy generation from wood wastes that otherwise would have released their carbon to the atmosphere relatively quickly. The choice of biomass energy generation technologies also matters. Biomass fueling thermal and combined heat and power systems typically produce greenhouse gas benefits sooner than large-scale biomass electricity generation.

Finally, we’d emphasize that there are many other considerations besides greenhouse gas emissions when making energy policy — these include energy security, air quality, forest recreation values, local economics, other environmental impacts of extracting fossil fuels (and not just greenhouse gas emissions of burning fossil fuels), and quality of place, among others. Policymakers need to weigh all these factors in making energy policy.

What we’ve done is put a much sharper point on one piece of the story — greenhouse gas emissions. Until our study came out, it was widely assumed that using wood for energy was immediately carbon- neutral. How this new insight factors into the public’s view of using wood for energy remains to be seen.

As for Manomet, our role is to inform society with science, with the hope that a better informed society will make better decisions.

3 thoughts on “The Woody Biomass for Energy Debate- Manomet Study”

  1. Opponents of biomass use any and all reasoning to bash biomass harvesting. A very recent article claims that 30 million acres of American forests will be clearcut if biomass harvesting is embraced. They want no part of any subsidy to accelerate biomass harvesting. Yes, caution must be used, as I have seen examples in MA where the state is making a patchwork of some state forests, claiming environmental carbon neutrality. What is also amazing is that those “progressive” citizens bought the story.

    Cellulosic ethanol production continues to make steps in polishing their processes, and are much closer to their promise of acceptable efficiency and economy. It remains to be seen whether such biofuels will be cost and environmentally effective. However, biomass producing electricity has seemingly arrived as a significant contributor to our energy puzzle. There are many success stories where supply easily meets demands. Out here in the west, we have ample supplies of dead trees, as well as choked green stands that desperately need thinning.

    Opponents (including Al Gore) claim that we’ll simply repeal dozens of environmental laws to mow our forests down to bare mineral earth, when the truth is that we CAN utilize excess biomass and mill waste to offset coal usage. In some areas, we NEED those subsidies because in places like California, where power plants won’t buy forest biomass when they get agricultural biomass for free!! (They only pay transportation costs)

    The other part of the issue is the eco-preference that “not one stick” ever be cut off public lands, including VAST acreage of dead forests. They also wrongly believe that burning forests are “carbon neutral”. Let’s hope the new Planning Rules and Forest Plans will address such fallacies and beliefs. We need to trumpet the wide array of benefits of thinning crowded and/or dead forests, and capturing the energy, as well as mitigating forest carbon release. The idea of a closed carbon system regarding forests is flawed. Catastrophic wildfires severely impact soils and push CO2 far into the upper atmosphere, resulting in less carbon re-capture in future decades. Scale it up to millions of acres and you have a radically unbalanced carbon cycle.

  2. Biomass seems to be another popular buzz word with the FS lately. I think it’s another of those words that mean different things to different people. When I go out and cut my four cords of “biomass” (firewood) every summer, I wonder why the price I pay the FS is going up while they are subsidizing biomass. The economics of bio mass are challenging. I am convinced they need an integrated approach, a method that yields multiple products from the forest. Lumber, cordwood, fence posts, pulpwood, and hog fuel. All of these would be bio-mass as I see it. There seems to be a bias against making a profit with natural resources, they want to make electricity from burning non-merchantable bush and saplings and not make any lumber. Our local sawmill makes boards, chips, and electricity (co-generation). They need to mix in higher value products like sawlogs to support the low to no value hog fuel or else plan on a continuous program of subsidies.

  3. Also, a big part of the problem is that private southern landowners, who were promised a return for their biomass on pine plantations many years ago, will suddenly have a product and profits for the trees they should thin. That would also lead to increased growth of sawlog trees and another nice payday down the road, leading to another round of clearcuts. Otherwise, those landowners were expected to thin their plantations without much of a return, hoping to gain it back when they harvest the sawlogs.

    With private biomass becoming valuable, the Nature Conservancy can’t buy the land for pennies on the dollar and then “flip it” to the Forest Service for a hefty profit. Yep, there’s a LOT more at-stake than meets the eye, eh?!?


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