Hybrid Life-Cycle Assessment

We combine high-resolution process data with multi-regional input-output tables for complete and scientifically rigorous environmental analyses.

The limitation of traditional approaches

Life Cycle Assessment (LCA) is the most widely used tool for quantifying the environmental impacts of products and services. However, in its traditional formulation — called process-based LCA — it suffers from a methodological problem known as truncation error.

The problem arises from the need to "cut" system boundaries: in practice, only direct suppliers and at most a few upstream levels are considered. But real supply chains extend for dozens of levels, involving hundreds of sectors and countries. Everything outside the boundaries is simply ignored.

Scientific literature documents systematic underestimations: depending on the product and impact category, truncation error can lead to ignoring 20% to 50% of actual emissions.

The hybrid approach

The solution to this problem is Hybrid LCA, which integrates two complementary types of data:

• Process data — Detailed inventories for key value chain processes: energy consumption, materials, transport, waste. These data offer high spatial and temporal resolution, allowing to capture the specificities of the analysed system.
• Multi-regional input-output tables (MRIO) — Matrices representing economic flows between all sectors of all countries. Databases such as EXIOBASE and GTAP contain information on over 160 sectors and 40+ regions, with environmental extensions that allow calculating emissions embodied in each transaction. These tables guarantee systemic completeness: no flow is truncated, because the system includes the entire global economy.

By combining both approaches, we get the best of both: the precision of process data where needed (processes under client's direct control) and the completeness of MRIO tables for the rest of the supply chain.

Why we prefer physical flows

Traditional MRIO tables use monetary data: flows between sectors are expressed in euros or dollars. But the price of a good does not necessarily reflect its environmental impact. A cheap component can be highly polluting; an expensive material may have a modest footprint.

That's why we prioritise physical flows where possible: kilograms of material, kilowatt-hours of energy, tonne-kilometres of transport. This approach reduces sensitivity to price fluctuations and improves estimate accuracy, especially for products with high material or energy content.

Scientific validation

The hybrid approach we adopt is well established in decades of academic research and supported by a broad body of peer‑reviewed literature.

Perkins & Suh (2019) systematically analysed the implications of hybridisation on accuracy and precision, demonstrating that the hybrid approach significantly improves LCA estimate accuracy — with average increases of 38% in greenhouse gas emissions after hybridisation — without compromising statistical precision.

Hagenaars et al. (2025) conducted a systematic review of Hybrid LCA applications to sustainable transitions, confirming the methodological advantages and identifying best practices for integrating process and input-output data.

MARIO: our framework

To implement this methodology we developed MARIO (Multi-regional Analysis of Resources, Inputs and Outputs), an open-source Python framework for environmental input-output analysis.

MARIO allows to:

• Build counterfactual scenarios to evaluate the impact of strategic choices
• Calculate product and organisation footprints with Scope 3 completeness
• Disaggregate sectors and regions for high-resolution analysis
• Integrate technology shocks and decarbonisation assumptions

The framework is published in peer-reviewed scientific journals and available open-source:

Repository GitHub · Scientific publication

Applications

This methodology supports a range of concrete applications:

• Organisation carbon footprint (GHG Protocol Corporate Standard) and product carbon footprint (ISO 14067)
• Greenhouse gas inventories according to ISO 14064
• CSRD/ESRS sustainability reporting with complete and traceable Scope 3 data
• Scenario analysis for decarbonisation strategies and science-based targets
• Supply chain impact assessment and supplier screening

Scientific publications

The methodologies we adopt are documented in peer-reviewed publications in international scientific journals. Our team actively contributes to academic research in life cycle assessment and circular economy.

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