Airport Greenhouse Gas Emissions Management - Zurich Airport

4 INVENTORY
4.1 Background
4.1.1 This section is designed to assist an airport operator developing an inventory of GHG emissions.
The intent is to outline the essential elements of the two documents, ACRP (2009) and WRI
(2004).
4.1.2 The WRI document (2004) sets down five principles that should be kept in mind.
inventory
• Relevance – The inventory serves the decision-making needs of the users.
• Completeness – All relevant sources and emissions are counted and reported.
• Consistency – Consistent methodologies allow for meaningful comparison with other
periods and with other sites.
• Transparency – Full discloser of data sources and methodologies with a clear audit trail.
• Accuracy – Emissions quantification is systematically neither over nor under actual
emissions, and uncertainties minimized, within reason. Users are able to make decisions
with reasonable assurance as to the integrity of the information.
4.2 Purpose of Inventory
4.2.1 The purpose of the inventory will depend on what is driving the decision to address GHG emissions
as discussed in Section 3. Understanding this will guide the breadth of sources that need to be
included within an inventory and the appropriate level of detail and accuracy required.
4.2.2 In general terms, unregulated and voluntary inventories, such as an airport CSR or sustainability
programme, should include as wide a range of relevant sources and emissions species as practical.
A regulatory regime, such as the EU ETS, will usually specify exactly which sources and species
should or should not be included.
4.3 Pollutants Species
4.3.1 The ACRP (2009) defines 3 levels of pollutant categories that airport operators can address.
• Level 1: CO 2 only. The ACI Europe ACA scheme addresses only CO 2 . Generally CO 2
represents over 95 percent of the emissions at most airports.
• Level 2: Gases covered in the Kyoto Protocol, which are carbon dioxide (CO 2 ),
methane (CH 4 ), nitrous oxide (N 2 O), hydrofluorocarbons (HFC), perfluorocarbons
(PFC), sulphur hexafluoride (SF 6 ). This is the level recommended by the ACRP
(2009).
• Level 3: All six Kyoto pollutants, precursors and any others exerting a GHG effect.
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