In recent years there has been growing concern over the atmospheric build-up of greenhouse
gases, particularly carbon dioxide, as a cause for global warming. The science underlying
this concern has been compiled in the various reports of the Intergovernmental Panel on Climate Change (IPCC), including the First, Second, and Third Assessment Reports on Climate Change (IPCC 2001).
It is well recognized that the major greenhouse gas is carbon dioxide and the major cause of human-generated carbon in the atmosphere is the burning of fossil fuels for energy. It is also well recognized that biological systems can play a significant role in the level of atmospheric carbon. Deforestation and land-use change both can contribute to increased emissions of carbon dioxide.
However, this is reversible in that carbon can be sequestered in expanding biological systems, particularly forests (IPCC 2001). The process of forest growth captures carbon in the cells of the wood and the carbon is held captive in the forests. Additionally, the carbon continues to be held in the cells of wood that is used for long-lived products such as lumber and poles, thereby mitigating the build-up of atmospheric carbon dioxide.
A number of studies have compared the total life cycle energy utilization of the use of wood products with the use of substitute materials such as steel, concrete, bricks and aluminum. These studies were undertaken by different researchers at different times in countries in North America and Europe, as well as New Zealand. The examinations included a wide range of different construction materials as well as a detailed case study investigating the use of different materials for utility poles.
Without exception, all the studies found that the total energy requirements associated with wood materials are substantially lower than those of other commonly substituted materials.
The greenhouse gas implications will vary, depending upon the type of energy used. At the one extreme, nuclear and hydropower create no greenhouse gases in their direct production of energy, although the construction of nuclear and hydro facilities undoubtedly generates some greenhouse gas emissions.
Additionally, emissions of carbon vary with the type of fossil fuel used. For example, natural gas emits substantially less carbon dioxide per unit of power than does coal. Nevertheless, there is no question but that in most countries, where fossil fuels provide a substantial part of the energy base, wood materials will emit significantly less carbon dioxide than would the commonly substituted materials.
It is clear from the findings of Kunniger and Richter (1995) that wooden poles are more environmentally benign than concrete or steel poles with regard to their utilization of energy and their potential to contribute to atmospheric carbon dioxide. The KR study concludes “the results show that impregnated roundwood utility poles in fact have certain environmental benefits when considered over their whole life cycle.” These findings are consistent with the earlier results of Koch (1992).
An estimate of the effect of converting wood poles to steel shows that, although the greenhouse gas emissions associated with pole conversion were modest compared to the national total, they were nevertheless a significant percent of US annual emissions. Emissions would increase by about 163 million tons of CO2 equivalent greenhouse gas, approximately 2.8 percent of US annual emissions (estimated at 5.28 billion tons of CO2 annually). Thus, the conversion from wood utility poles to steel would result in a small but significant increase in total US emissions.
More broadly, these studies provide empirical confirmation of concepts developed in the Third Assessment Report (IPCC 2001), whereby the substitution of high energy intensive materials for low-energy-using wood materials contributes substantially to the overall increase of carbon dioxide emissions through their overall higher energy requirements.
About the Author
Author or editor of 13 books on forestry and resources, Dr. Roger Sedjo is Senior Fellow in the Energy and Natural Resources Division of Resources for the Future. He is also director of that organization’s Forest Economics and Policy Program. He holds a Ph.D. in economics.
Note: This discussion is available in an expanded version, “Wood Materials Used as a Means to Reduce Greenhouse Gases (GHG): An Examination of Wooden Utility Poles,” from a member of the North American Wood Pole Coalition or in the utility sections of www.WWPInstitute.org or www.preservedwood.com
gases, particularly carbon dioxide, as a cause for global warming. The science underlying
this concern has been compiled in the various reports of the Intergovernmental Panel on Climate Change (IPCC), including the First, Second, and Third Assessment Reports on Climate Change (IPCC 2001).
It is well recognized that the major greenhouse gas is carbon dioxide and the major cause of human-generated carbon in the atmosphere is the burning of fossil fuels for energy. It is also well recognized that biological systems can play a significant role in the level of atmospheric carbon. Deforestation and land-use change both can contribute to increased emissions of carbon dioxide.
However, this is reversible in that carbon can be sequestered in expanding biological systems, particularly forests (IPCC 2001). The process of forest growth captures carbon in the cells of the wood and the carbon is held captive in the forests. Additionally, the carbon continues to be held in the cells of wood that is used for long-lived products such as lumber and poles, thereby mitigating the build-up of atmospheric carbon dioxide.
A number of studies have compared the total life cycle energy utilization of the use of wood products with the use of substitute materials such as steel, concrete, bricks and aluminum. These studies were undertaken by different researchers at different times in countries in North America and Europe, as well as New Zealand. The examinations included a wide range of different construction materials as well as a detailed case study investigating the use of different materials for utility poles.
Without exception, all the studies found that the total energy requirements associated with wood materials are substantially lower than those of other commonly substituted materials.
The greenhouse gas implications will vary, depending upon the type of energy used. At the one extreme, nuclear and hydropower create no greenhouse gases in their direct production of energy, although the construction of nuclear and hydro facilities undoubtedly generates some greenhouse gas emissions.
Additionally, emissions of carbon vary with the type of fossil fuel used. For example, natural gas emits substantially less carbon dioxide per unit of power than does coal. Nevertheless, there is no question but that in most countries, where fossil fuels provide a substantial part of the energy base, wood materials will emit significantly less carbon dioxide than would the commonly substituted materials.
It is clear from the findings of Kunniger and Richter (1995) that wooden poles are more environmentally benign than concrete or steel poles with regard to their utilization of energy and their potential to contribute to atmospheric carbon dioxide. The KR study concludes “the results show that impregnated roundwood utility poles in fact have certain environmental benefits when considered over their whole life cycle.” These findings are consistent with the earlier results of Koch (1992).
An estimate of the effect of converting wood poles to steel shows that, although the greenhouse gas emissions associated with pole conversion were modest compared to the national total, they were nevertheless a significant percent of US annual emissions. Emissions would increase by about 163 million tons of CO2 equivalent greenhouse gas, approximately 2.8 percent of US annual emissions (estimated at 5.28 billion tons of CO2 annually). Thus, the conversion from wood utility poles to steel would result in a small but significant increase in total US emissions.
More broadly, these studies provide empirical confirmation of concepts developed in the Third Assessment Report (IPCC 2001), whereby the substitution of high energy intensive materials for low-energy-using wood materials contributes substantially to the overall increase of carbon dioxide emissions through their overall higher energy requirements. About the Author
Author or editor of 13 books on forestry and resources, Dr. Roger Sedjo is Senior Fellow in the Energy and Natural Resources Division of Resources for the Future. He is also director of that organization’s Forest Economics and Policy Program. He holds a Ph.D. in economics.
Note: This discussion is available in an expanded version, “Wood Materials Used as a Means to Reduce Greenhouse Gases (GHG): An Examination of Wooden Utility Poles,” from a member of the North American Wood Pole Coalition or in the utility sections of www.WWPInstitute.org or www.preservedwood.com
