An indicator for Criterion 5: Maintenance of Forest Contribution to Global Carbon Cycles
What is indicator and why is it important?
Nearly 80 percent of gross 7,054.2 Tg of CO2 equivalents emitted by United States in 2007 came from combustion of fossil fuels for energy. If combustion of forest biomass for energy occurs in lieu of burning fossil fuels, n fossil fuel emissions may be reduced. If 100 percent of removed/harvested forest biomass is eventually regenerated and, n re will be a net reduction in greenhouse gas (GHG) emissions because burning of nonrenewable fuels (e.g., coal) was avoided. If forest sources of wood are used, net offset of emissions is attained slowly over time and pace of attaining offsets depends on what would have happened to wood source (growth, decay) if it was not used for energy.
What does indicator show?
In 2007, more than 2,100 trillion BTUs (British rmal Units) were generated in United States from combustion of wood in form of fuelwood logs, wood chips, mill wastes, and black liquor at pulp mills (fig. 24-1). This amount is about 2 percent of all energy consumed in 2007. Burning fossil fuels is primary remaining source for generating BTUs. Most wood energy was consumed in industrial applications (67 percent), followed by residential (21 percent), electric utility (8 percent) and commercial applications (3 percent). energy generated by burning wood has decreased from a high level in 1989, but wood used for electric power production has increased about 90 percent from a low level in 1989. Because burning of wood may potentially avoid GHG emissions over a period of time given sustainable forest management, avoided CO2 emissions may be stated in terms of offsetting burning of several alternate fossil fuels. burning of wood for energy in 2007 avoided emissions of approximately 59, 35, or 48 Tg CO2e if coal, natural gas, or fuel oil was fossil energy source, respectively (fig. 24-2). A great variety of electric utility applications have used wood as a source of energy across United States in 2007 (fig. 24-3), often through co-generation at wood processing facilities. Most of electric utility sites are located near sources of forest biomass, such as West coast, Lake States, Norast, and Souast. Currently, hundreds of electric utility plants use wood derived as waste from forest product industries for power generation and, thus, avoid GHG emission. However, amount of power produced from wood residue burning is a small fraction of power produced by fossil fuel electric utility plants nationwide.
What has changed since 2003?
use of wood as an energy source and reby avoidance of fossil fuel emissions has been decreasing since mid-1990s. Although widespread use of, and access to, wood as an energy source exists in United States, it still represents less than 1 percent of power generation nationwide.