Structural Path Analysis of Carbon Emissions in Supply Chains

Structural Path Analysis (SPA) offers a rigorous framework for tracing greenhouse-gas emissions through the complete network of interlinked production and consumption activities. By decomposing multi-sector input-output models into discrete pathways, SPA quantifies both direct emissions at the point of production and indirect emissions embodied in upstream inputs. This approach reveals the “hidden” contributions of final-demand categories and intermediate industries, identifies critical hotspots within global and regional supply chains, and supports targeted mitigation measures. SPA has been applied across diverse sectors—from power generation and steel to construction and agriculture—illuminating how shifts in consumption, trade flows and industrial structure propagate through complex value chains. The insights derived inform policy on carbon pricing, technology adoption and supply-chain optimisation, enabling stakeholders to prioritise interventions that deliver greatest reductions in embodied carbon intensity while maintaining economic resilience.

Research from Nature Portfolio

Recent studies have harnessed SPA in combination with health-impact assessments to map particulate-matter pathways through energy supply chains and quantify associated mortality burdens. By distinguishing direct and indirect electricity use, researchers demonstrated that indirect consumption drives a significantly larger share of air-pollution–related deaths than on-site emissions. The analysis further partitioned domestic and international final-demand effects, revealing that export-oriented rice supply chains contribute substantially to pollution-linked fatalities. Methodological innovations include integration of structural decomposition with inventory databases, enabling simultaneous evaluation of environmental and public‐health outcomes and offering a template for analogous analyses of carbon emissions along complex trade networks.

Structural Path Analysis of Carbon Emissions in Supply Chains publication trend

The graph below shows the total number of articles in structural path analysis of carbon emissions in supply chains across all publications each year (not limited to Nature Index journals).

Technical terms

Structural Path Analysis (SPA): A technique that decomposes input-output models into ordered chains of production and consumption activities to quantify direct and indirect emissions.

Multi-Regional Input-Output (MRIO) Analysis: A framework that extends national input-output tables to multiple regions or countries, capturing cross-border trade and emission transfers.

Environmental Extended Input-Output Analysis (EEIOA): An approach that integrates environmental data—such as emission coefficients—into economic input-output models to link economic activity with environmental impacts.

Embodied Emissions: Greenhouse-gas releases associated with all upstream processes required to produce a final good or service, including extraction, manufacturing and transport.

Final Demand: The consumption, investment and export expenditures that drive production and trigger emissions throughout the supply chain.

References

1. Structural Path Analysis of Fossil Fuel Based CO2 Emissions: A Case Study for China. PLOS ONE (2015).
2. Greenhouse Gas Emissions of Global Construction Industries. IOP Conference Series Materials Science and Engineering (2022).
3. Critical supply chains for mitigating PM2.5 emission-related mortalities in India. Scientific Reports (2021).
4. Study on the Mechanism of Agricultural Greenhouse Gas Emission Reduction Under Macro Emission Reduction Measures. Agriculture (2024).