Accounting for Emissions and Sinks from the Biogeochemical Cycle of Carbon in the U.S. Economic Input‐Output Model

Abstract

Summary Biogeochemical cycles are essential ecosystem services that continue to degrade as a result of human activities, but are not fully considered in efforts toward sustainable engineering. This article develops a model that integrates the carbon cycle with economic activities in the 2002 U.S. economy. Data about the carbon cycle, including emissions and sequestration flows, is obtained from the greenhouse gas inventory of the U.S. Environmental Protection Agency. Economic activities are captured by the economic input‐output model available from the Bureau of Economic Analysis. The resulting model is more comprehensive in its accounting for the carbon cycle than existing methods for carbon footprint (CF) calculations. Examples of unique flows in this model include the effect of land‐use and land‐cover change on carbon dioxide flow within the U.S. national boundary, carbon sequestration in urban trees, and emissions resulting from liming. This model is used to gain unique insight into the carbon profile of U.S. economic sectors by providing the life cycle emissions and sequestration in each sector. Such insight may be used to support policies, manage supply chains, and be used for more comprehensive CF calculations.

Footprints of carbon and nitrogen: Revisiting the paradigm and exploring their nexus for decision making

“…For details about the method, readers are referred to (Singh and Bakshi, 2014). The Ghosh matrix and the V ph vector for the current inventory correspond to the 2002 US economy.…”

“…The footprint calculations in this work are based on the inventory developed in (Singh and Bakshi, 2014) and (Singh and Bakshi, 2013) for the 2002 US input-output model. This inventory connects the biogeochemical cycles of carbon and nitrogen with the most recent IO model of the economy.…”

“…Examples of these flows are C sink in farmland or ranchland that produces goods responsible for supporting production from the given system. Various flows that can be categorized as carbon sequestration are included in the Eco-LCA C inventory and discussed in detail in (Singh and Bakshi, 2014). The output-side carbon footprint includes emissions of CO 2 to air, water or land.…”

“…Recently, other emissions have also been given tremendous importance due to significant increase in C emissions related to Land Use and Land Use Change (LULUC) and agricultural emissions due to liming and urea fertilization. However, quantification of these emissions on life cycle scale is challenging and life cycle inventory for inclusion of these streams at this scale has been developed only recently in the Eco-LCA model (Singh and Bakshi, 2014).…”

“…Utilizing this shift in paradigms we suggest "input-side" (impact on ecosystems due to resource extraction) and "output-side" (impact on ecosystems due to waste and emissions disposal) footprint measures and apply them to improve carbon and nitrogen footprints. The choice of these footprints is based on insights developed in (Singh and Bakshi, 2014) and (Singh and Bakshi, 2013) about the dependence of human systems on various flows that constitute carbon and nitrogen cycles. This work shows that decisions can vary with the perspective adopted for development of the footprint metric.…”