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Biofuel forests for the future?
by -- April 26th, 2016

The U.S. Senate seems determined to declare the substitution of wood for coal as a positive step to minimize the potential for global climate change. Under the Senate’s latest version of the energy bill, the various states, as they develop plans to reduce CO2 emissions to comply with the EPA’s Clean Power Plan, could count wood as a “carbon neutral” fuel. 

Somehow the Senators are able to overlook the fact that between now and 2030—the target for the President’s commitment to reduce CO2 emissions for the Paris accord—burning wood would substantially increase CO2 emissions to the atmosphere.  When trees are cut to provide biofuel for the generation of electricity, nearly all the carbon they contain is released to the atmosphere immediately.   And, because trees have lower energy content than coal, burning wood releases more CO2 per unit of energy generated than coal. 

The argument that trees are carbon-neutral inasmuch as they grow back after harvest is a moot point because most trees will not return to their preharvest stature before the 2030 target commitment of the Paris Climate accord.  Young trees grow faster than old trees, but it’s the comparative storage of carbon in the year 2030 that will determine whether trees are carbon-neutral or a source of CO2 to the atmosphere.  This is a carbon storage question, not an uptake or carbon sequestration question.  

Arguments that regrowing forests will pay back the carbon debt over 100 years are irrelevant; the most harmful effects of rapid global climate change will be “locked in” in 100-year’s time. 

Widespread harvest of mature forests for biomass energy will motivate the planting of short-rotation plantation forests to supply biomass. However, when we confront models of forest economics with data, they fail.  One-hundred and fifty years of forest management in Europe have not contributed to climate change mitigation.  Plantation forestry results in low-diversity stands with lower value for wildlife habitat.  Most studies showing a positive effect of burning wood to generate electricity ignore the uptake and sequestration of CO2 that might have occurred if the forests had remained intact.

The forest products industry likes to cut trees, but trees are the most efficient way we know to remove CO2 from the atmosphere. 

 

References

Mackey, B., I.C. Prentice, W. Steffen, J.I. House, D. Lindenmayer, H. Keith and S. Berry.  2013.  Untangling the confusion around land carbon science and climate change mitigation policy.  Nature Climate Change 3: 552-557.

Naudts, K., Y. Chen, M.J. McGrath, J. Ryder, A. Valade, J. Otto and S. Luyssaert.. 2015.  Europe’s forest management did not mitigate climate warming.  Science 351: 597-600.

Ricke, R.L. and K. Caldeira. 2014.  Maximum warming occurs about one decade after a carbon dioxide emission.  Environmental Research Letters 9: 124002

Root, H.T., and M.G. Betts. 2015.  Managing moist temperate forests for bioenergy and biodiversity.  Journal of Forestry 113: http://dx.doi.org/10.5849/jof.14-114

Schulze, E.D., C. Korner, B.E. Law, H. Haberl, and S. Luyssaert.  2012.  Large-scale bioenergy from additional harvest of forest biomass is neither sustainable nor greenhouse gas neutral.  Global Change Biology Bioenergy   doi: 10.1111/j.1757-1707.2012.001169.x

Ter-Mikaelian, S.J. Colombo and J. Chen. 2015.  The burning question: Does forest bioenergy reduce  carbon emissions?  A review of common misconceptions about forest carbon accounting.  Journal of Forestry 113: 57-68.

1 Comment

  1. Ted Johnson
    Apr 26, 2016

    Yes, you are right about all. First of all, there is no way to justify cutting down any forest for fuels which is easily done, a political buzzword, not very efficient in harvesting, high cost for the harvesting/processing, low heating value with fresh cut high moisture contents, and lower energy efficiency in combustion. thus more required. It is interesting to observe that it takes more energy to dry the wood, than you will gain in a higher heating value. To do that four any market you will normally end up using Fossil fuels, the very fuels you are suppose to replace.
    There is no way we should be cutting, especially clear cutting, any forest for pellets to ship to another country. We need this energy here, but not at those prices. Short rotation crops do not make sense financially , just as pellets and biochar. Look, gasification, another buzzword, has been around for 100,000 years,
    The only way to utilize wood is to harvest it as residues, such as that remaining after logging operations, fire hazards, insect infestation, dead trees , thinnings, ,residues from saw mils, selected construction debris without any chemicals, slash, brush, unwanted species, and such..
    With all that in mind. it still is not feasible unless you have the most efficient machinery to harvest, process(dry and provide an optimum fuel size), and then use those fuel in one stage of combustion of at least 88% efficiency and with air emissions that are at least 10% lower than the highest standards in any country. Can it be done? For sure, it has been done for over thirty years. There is no way that any use of wood for energy has to be subsidized, use grants or other incentives, even carbon credits, or other monetary incentives to be feasible, such as providing grans to buy wood stoves to use pellets. Either the technology stands by itself, or it is not the right tecnology and that is the same for any part of a project. There is no way you can sustain any project using wood as a fuel unless you can sustain the source. The forest is the only reliable source, if you attend to it.

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