S M Nazmuz Sakib Gas-Mix Phase Number for Supply Chain Greenhouse Gas Emissions
サプライチェーン温室効果ガス排出のためのS M Nazmuz Sakibガス混合相数 (AI 翻訳)
Sakib, S M Nazmuz
🤖 gxceed AI 要約
日本語
サプライチェーンGHG会計では複数ガスをCO2換算で合算するが、ガス構成の変化は隠れる。米EPAの2022年データを用い、KLダイバージェンスに基づく「Sakib数」を提案。マージンと生産段階のガス構成の乖離を定量化し、畜産セクターで高く、サービス業で低いことを示した。
English
Supply-chain GHG accounting aggregates gases into CO2e, hiding composition shifts. Using EPA 2022 data, this paper introduces the Sakib number, a KL-divergence-based index quantifying gas-mix divergence between margin and production phases. Livestock sectors show high values; services near zero. Provides a transparent, data-driven method for multi-gas analysis.
Unofficial AI-generated summary based on the public title and abstract. Not an official translation.
📝 gxceed 編集解説 — Why this matters
日本のGX文脈において
日本ではSSBJ開示やScope3算定が進むが、ガス構成の詳細分析は稀。本指標はサプライチェーン排出の質的理解を深め、セクター別の排出削減優先度の検討に示唆を与える。
In the global GX context
Globally, GHG accounting standards (GHG Protocol, ISO) focus on CO2e totals. This paper adds a novel dimension by analyzing gas-mix divergence along supply chains, which could inform more nuanced Scope 3 strategies and sector-specific mitigation priorities.
👥 読者別の含意
🔬研究者:Provides a new information-theoretic metric for analyzing multi-gas composition in supply-chain emission factors, useful for methodological advancement.
🏢実務担当者:Offers a way to identify sectors where gas composition differs significantly, potentially informing more targeted Scope 3 reduction efforts.
🏛政策担当者:Highlights the importance of gas-specific data in supply-chain accounting, which could influence future disclosure requirements.
📄 Abstract（原文）
Most supply-chain greenhouse gas (GHG) accounting aggregates multi-gas emissions into a single carbon-dioxide-equivalent (CO 2 e) factor per monetary unit using global warming potentials. This aggregation hides how the composition of gases changes between different stages of the value chain. Using the publicly available U.S. Environmental Protection Agency (EPA) "Supply Chain Greenhouse Gas Emission Factors v1.3 by NAICS-6" dataset for 2022, this paper introduces a new information-theoretic index, the S M Nazmuz Sakib Gas-Mix Phase Number (short: Sakib number). For each NAICS-6 commodity, the Sakib number is defined as the Kullback-Leibler divergence between the normalized gas composition of the "with-out margins" phase and the "margins" phase of the spend-based emission factors. The Sakib number quantifies how strongly the gas mix of margin-related emissions diverges from the gas mix of upstream production emissions. A value close to zero indicates that margins have a similar gas composition to production, whereas larger values identify sectors where the composition of GHGs in margin-related activities differs markedly. An economy-wide mean over all sectors, the S M Nazmuz Sakib Supply-Chain Gas-Mix Phase Constant (Sakib constant), is estimated for the 2022 U.S. factors as C S ≈ 0.0206 (in natural-log units). 1 Using only the EPA data (no simulation), ten data-based illustrations are constructed. These show: (i) the distribution of CO 2 e intensities across 1,016 NAICS-6 commodities; (ii) top contributors by CO 2 e intensity and by Sakib number; (iii) sec-toral patterns in gas-mix divergence; and (iv) how the Sakib number varies with methane share, sector group, and margin share. Livestock-related NAICS codes (e.g., beef cattle ranching and farming) exhibit the highest Sakib numbers, while many service sectors have values close to zero, indicating nearly identical gas mixes between phases. The proposed Sakib number and Sakib constant provide a transparent , mathematically grounded way to characterize multi-gas composition shifts along supply chains using existing spend-based factors.
🔗 Provenance — このレコードを発見したソース
- openalex https://doi.org/10.5281/zenodo.17796933first seen 2026-08-02 18:37:07
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