The National Academies Press

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From page 35... ... 3 QUALITIES OF AN EFFECTIVE TOOL In the previous chapter current methods for measuring emissions were reviewed and a definition of the carbon footprint of transportation in the supply chain was presented. In order to critique current methods a set of qualities that can be used to evaluate tools must be developed. Read the entire page →
From page 36... ... Both of these definitions include the idea of a difference between high-level standards that provide only guidance regarding calculating emissions and actual tools used for calculating emissions from specific activities. We consider existing greenhouse gas accounting tools to fit into a hierarchy of three different levels: Programs, Methodologies, and Tools. Read the entire page →
From page 37... ... sources. The tool allows for the use of two primary methodologies: one based on total fuel use and the other based on activity data. Read the entire page →
From page 38... ... simulations, surveys, LCA, and econometric analysis. Shippers may prefer activity-based approaches, as they can be used to estimate emissions from more widely available data, such as shipment distances and weight, rather than fuel consumption. Read the entire page →
From page 39... ... When evaluating the performance of any tool it must be done with the intended use in mind. Some tools may fulfill multiple roles, or fill different roles for different users. Read the entire page →
From page 40... ... Working in this manner the tool is used for all three roles, though not necessarily for all users. For carriers the tool acts as both an external reporting tool and an internal control tool. Read the entire page →
From page 41... ... Whether the carbon footprint is a metric that measures performance across the supply chain or within a functional area is dependent on how it is defined. Metrics can be evaluated in a number of categories, but designing metrics that excel in each category is not practically possible. Read the entire page →
From page 42... ... MEASURING ENVIRONMENTAL IMPACT Life Cycle Assessment provides a general framework for measuring the environmental burden of a product or function. Its general structure allows for application to a wide variety of systems, but also allows considerable freedom in implementation. Read the entire page →
From page 43... ... LCAs generally fall into two categories based on their purpose. An attributional LCA is focused on looking back on a product and determining what emissions can be attributed to it. Read the entire page →
From page 44... ... Figure 11: Breadth and Depth Rather than identify what is included in the program, the precision determines the level of detail the program provides. Depending on the level of aggregation in data sources or the approach for generating emissions, programs may provide more or less precision in their estimates of GHG emissions. Read the entire page →
From page 45... ... capture the relevant emissions, while the measurement must be precise enough to allow differentiation between the options. BREADTH, DEPTH, AND PRECISION IN PRACTICE The approaches of two popular GHG calculators provide an illustration of how the breadth, depth, and precision can vary between different programs, and how this impacts the ability to calculate emissions. Read the entire page →
From page 46... ... Figure 13: NTM Methodology80 NTM considers only emissions from transportation, and not additional logistics activities. The calculator does include CH4 and N2O in addition to CO2. Read the entire page →
From page 47... ... The Defra emissions factors are calculated using a survey methodology, which captures average vehicle fuel consumption and load factors for a number of different vehicle types. Emissions factors are provided per tonne-km for a number of different types of road vehicles and watercraft, as well as for rail and air. Read the entire page →
From page 48... ... Carbon Disclosure Project Global Reporting Initiative Greenhouse Gas Protocol Relevance Relevance Relevance Faithful Representation Reliability Completeness Comparability Clarity Consistency Timeliness Comparability Transparency Understandability Timeliness Accuracy Verifiability Verifiability Table 2: Comparison of Principles The high degree of similarity around their principles is immediately obvious. All three programs have been designed around the core principles of financial accounting. Read the entire page →
From page 49... ... reassurance that the results can be used as part of an overall performance measurement system. SUMMARY In all three performance frameworks a common distinction between internal and external uses are present. Read the entire page →
From page 50... ... increase the relevance of the results to making decisions; the ability to incorporate the results into benchmarking and information sharing; and the trustworthiness of claims based on the results. 53 Baldo, G Read the entire page →
From page 51... ... 76 Suh, S Read the entire page →

From page 35...

... 3 QUALITIES OF AN EFFECTIVE TOOL In the previous chapter current methods for measuring emissions were reviewed and a definition of the carbon footprint of transportation in the supply chain was presented. In order to critique current methods a set of qualities that can be used to evaluate tools must be developed.