Establishing CO2 Emission Calculation Rules for the Entire Software Lifecycle to Promote the Creation of Low-Carbon Software-Related Businesses

NTT Advanced Technology Corporation (NTT-AT), as part of its efforts toward the decarbonization of the software industry, participated in the Japan Environmental Club's*1 Working Group on Decarbonization in the Software Field. Through these discussions, it has established CO2 emission calculation rules covering the entire lifecycle of software products*2. These rules enable the calculation of CO2 emissions associated with the procurement, development, operation, and disposal of software products, in accordance with the Ministry of Economy, Trade and Industry's (METI) 'Carbon Footprint Guidelines'*3. This achievement extends the scope of CO2 emission calculations for software products, which were previously limited to the procurement and development stages, to the entire lifecycle, including operation and disposal. It promotes the enhancement of corporate value for software development companies, operators, and procurers through the promotion of green procurement and its use in Scope 3 calculations and reporting.

Leveraging 30 years of knowledge and experience in LCA*4 consulting, NTT-AT made proposals for the establishment of these calculation rules and facilitated consensus among the members of the working group. The company will continue to develop these calculation rules and contribute to the realization of a sustainable society.

1. Background

With the development and widespread use of AI, there is growing concern about the increasing environmental impact of the ICT industry*5*6, and the sustainability of AI technologies and data centers, which are composed of software, is gaining attention. While software itself does not consume physical resources, it is a factor that indirectly increases energy consumption through the use of clouds, data centers, networks, and user terminals, affecting the overall environmental impact of the ICT sector. In recent years, societal demands for companies to disclose their Scope 3 emissions have also intensified, and the disclosure of CO2 emissions originating from software products has become increasingly important as a factor in procurement evaluations and business transactions.

In March 2024, as part of the 'FY2023 Project to Support the Formulation of Product-Specific Calculation Rules for Carbon Footprints to Promote GX,' solicited by METI, a Cradle-to-Gate*7 version of the calculation rules (v1.0) was established, enabling the evaluation of CO2 emissions during development. However, since software products are generally used for a long period after development, evaluating CO2 emissions throughout the entire lifecycle, including operation and disposal, remained a challenge.

2. Achievements of This Initiative

The Working Group on Decarbonization in the Software Field at the Japan Environmental Club has established a Cradle-to-Grave*8 version of the calculation rules, expanding the scope of the conventional rules, which were limited to the procurement and development stages, to the entire lifecycle. These new rules enable the calculation of CO2 emissions from procurement, development, operation, to disposal, based on METI's 'Carbon Footprint Guidelines.' This has laid the foundation for formulating strategies to reduce CO2 emissions originating from software and for considering and promoting greening across the entire supply chain.