Greenhouse Gas Inventory Guide: Best Practices

This document provides guidance for air navigation service providers (ANSP) which are interested in assessing and managing their greenhouse gas (GHG) emissions. By producing this document, CANSO is encouraging ANSPs to consider how they can benefit from measuring their GHG inventory and how this is a crucial first step in identifying and delivering environmental improvement.

The purpose of this guide is to provide contextual material and best practices. While publicly available standards from the GHG Protocol describe the methodology to compile a GHG inventory, this guide also serves to clarify the GHG inventory methodology from an ANSP’s perspective, including the treatment of aircraft emissions. In addition, an International Organization for Standardization (ISO) describes how businesses can approach a GHG inventory in terms of assurance and verification. This document does not seek to restate these approaches but describes specific considerations for ANSP organisations, whether it is considering its emissions for the first time or has already begun assessing its own GHG inventory.

The approach is neither prescriptive nor mandatory. Instead, it seeks to be flexible and fully respects the variability and differences in local regulations and priorities around the world. While individual needs and the level of implementation differ between organisations, measuring environmental impacts is a responsible and necessary first step in effectively managing them. GHG inventorying also allows comparison between the internal inventories of each ANSPs, albeit while remaining conscious of contextual differences.

Using the GHG Protocol as guidance, the rest of this document focuses on Scope 1, Scope 2 and Scope 3 and how they apply to ANSPs. This includes the management of ‘estate’ related carbon impacts, such as the emitted carbon because of powering ANSP buildings and infrastructure associated with delivering ANSP operations and services. The document also includes value chain emissions including aircraft operations, and touches on avoided emissions which is defined as Scope 4.