The Importance of Carbon Footprint Estimation Boundaries

Abstract

Because of increasing concern about global climate change and carbon emissions as a causal factor, many companies and organizations are pursuing "carbon footprint" projects to estimate their own contributions to global climate change. Protocol definitions from carbon registries help organizations analyze their footprints. The scope of these protocols varies but generally suggests estimating only direct emissions and emissions from purchased energy, with less focus on supply chain emissions. In contrast, approaches based on comprehensive environmental life-cycle assessment methods are available to track total emissions across the entire supply chain, and experience suggests that following narrowly defined estimation protocols will generally lead to large underestimates of carbon emissions for providing products and services. Direct emissions from an industry are, on average, only 14% of the total supply chain carbon emissions (often called Tier 1 emissions), and direct emissions plus industry energy inputs are, on average, only 26% of the total supply chain emissions (often called Tier 1 and 2 emissions). Without a full knowledge of their footprints, firms will be unable to pursue the most costeffective carbon mitigation strategies. We suggest that firms use the screening-level analysis described here to set the bounds of their footprinting strategy to ensure that they do not ignore large sources of environmental effects across their supply chains. Such information can help firms pursue carbon and environmental emission mitigation projects not only within their own plants but also across their supply chain.

Towards a comprehensive system of methodological considerations for cities' climate targets

“…Matthews et al (2008) also demonstrated that only focusing on Scope 1 or Scope 1 and 2 emissions gives significantly lower results for firms than a full Scope 3 approach. Besides Hillman and Ramaswami (2010;also reported in Ramaswami et al, 2008), Kennedy et al (2010) have developed methodology which includes all indirect emissions, including upstream (product-chain) emissions, except from food and materials consumed in cities and emissions upstream of electric power plants.…”

“…The GHG accounts tend to use CO 2 e, including five of the most important GHG in addition to CO 2 (Murakami et al (2011);ICLEI, 2009;IPCC (2006); WRI-WBCSD, 2004). In this respect the methodologies reported in scientific papers differ, since they typically include only CO 2 (Heinonen and Junnila, 2011a;Weber and Matthews, 2008) or CO 2 , CH 4 and N 2 0 (Kennedy et al, 2010;Sovacool and Brown, 2010;Matthews et al, 2008;Ramaswami et al, 2008). It has been argued that using CO 2 is adequate from a practical perspective (Kennedy et al, 2010), since emissions of CO 2 tend to dominate when estimating the contribution of cities to global warming if the target is delimited to GHG emissions within the city boundaries.…”

Product level embodied carbon flows in bilateral trade

“…Carbon intensities of products have been estimated for industrial and manufactured goods using bottom-up approaches such as LCA (Matthews et al, 2008b). An extensive data search was conducted to collect product carbon intensity factors from multiple data sources (see Table 1).…”

OM Forum—Sustainable Operations Management: An Enduring Stream or a Passing Fancy?

“…Although this can add considerable complexity, it can also add vital perspective when considering sustainability, since the majority of a product's ecological impact often falls beyond any single tier's organizational boundaries. For example, Matthews et al (2008) estimate that the direct carbon emissions from an industry, on average, represent only 14% of that industry's total supply chain emissions.…”