Authors: Sam Sherrill, Ph.D. and Steve Bratkovich, Ph.D., Dovetail Partners
In 2011 Dovetail Partners conducted a study on the potential for carbon sequestration (storage) in three urban hardwood products: landscape mulch, biomass for fuel, and solid wood products. An Excel model was developed that focused specifically on tons of sequestered carbon dioxide equivalent (CO2e) of solid hardwood products from urban forests in the United States. Estimates for a 30-year period were developed for several situations based on assumptions about variations in carbon and wood harvest. The minimum estimate from the 2011 study was approximately 124 million tons of CO2e that could be sequestered (stored) nationally in urban hardwood products over a 30 year period.
Beginning in 2016, a follow-up study reconstructed the national model developed in the previous investigation to convert tons of sequestered CO2e into board feet. In addition, to making the results more user-friendly to urban wood industries, architects, and other interested parties, two products were selected, and sequestered CO2e was estimated. The hardwood products were a white oak dining room table and chairs, and green ash flooring.
At the national or macro-level, results of the current study show that a minimum or baseline estimate of approximately 53 billion board feet of urban hardwood lumber could be produced to sequester an equivalent of over 124 million tons in CO2e over a 30 year period. The 30-year total is equal to an average of 1.8 billion board feet per year. The maximum (upper limit) realistic estimates are 105 billion board feet (over 30 years) and 3.5 billion board feet (annually). Both the minimum and maximum estimates are under the lower limits from two independent studies by Bratkovich (2001) and MacFarlane (2009).
At the local or micro-level, results illustrate that a white oak dining room table with ten chairs (120 board feet) sequesters approximately 730 pounds of CO2e. Also, 105 board feet of green ash flooring sequesters 535 pounds of CO2e. These examples demonstrate the capacity for determining the carbon footprint of specific urban forest products. The white oak table and chairs, plus the flooring, results in a total CO2e weight of 1,265 pounds. This combination equals the CO2 emissions from a typical four-stroke gas-powered lawn mower for fourteen years.