Annex 4 analytical methods

The Domestic Footprint is a set of 16 LCA-based indicators, aimed at quantifying the environmental impacts of domestic production and consumption activities within the EU territory (Sanye Mengual & Sala, 2023). The Domestic Footprint aims at assessing the environmental impacts associated to emissions and resource extraction occurring within a Member State boundary (or the whole EU boundary) by adopting a production- and territorial-based perspective. Therefore, it accounts for both production and consumption activities taking place within the Member State’s domestic territory, e.g., from economic sectors such as industry, agriculture, energy, mining, and services; and also encompasses those impacts from households and government’s activities (e.g., transport, heating). The geographical scope of the Domestic Footprint is both the EU and Member States level.

The Domestic Footprint implements the Life Cycle Assessment (LCA) methodology, which entails four main steps:

1. Definition of goal and scope. This step includes the overall design of the study, e.g. the definition of the specific objectives of the study, the description of the modelling assumptions, the identification of the intended audience etc.
2. Definition of the life cycle inventory (LCI). In this step, data on inputs, i.e. resources, and outputs, i.e. emissions in the environmental compartments (air, water, soil), entering and leaving the system under study should be collected.
3. Assessment of the environmental impacts. In this step, the environmental impacts due to resources use and emissions reported in the inventory are calculated through the use of impact models. Sixteen indicators referred to different impacts are considered, such as climate change, eutrophication of water bodies, use of fossil, mineral and metal resources. Furthermore, endpoint assessment models can be applied to assess effects of these 16 impacts on 3 areas of protection, i.e. human health, ecosystem health, and natural resources. These 16 indicators may be normalised by global impacts and weighted to be summarised in one “single score” indicator. Compared to the 16 indicators, the single score indicator has the advantage of being more effective for communication and for supporting the selection of alternatives, but at the same time “hides” part of the complexity of the different environmental impacts, and introduce a subjective element, i.e. weighting, which may affect the results.
4. Interpretation of the results. This step is aimed at fulfilling the goal and scope of the study. Typical questions which may be answered at this stage are “which are the most impacting stages of the supply chain?”, “which are the effects on the environment of a certain policy?”. LCA results are characterised by different sources of uncertainty which should be considered in the interpretation of the results. The definition of the life cycle inventory is subject to the availability of average information describing the system. In addition, impact assessment models are characterised by uncertainties, which to different extent influence the robustness of the 16 indicators

The Domestic Footprint is a comprehensive collection of data on resource use (e.g., minerals and metals, energy carriers, land use, water use) and emissions to air (e.g., greenhouse gases, particulate matter), water (e.g., nitrogen, phosphorous) and soil (e.g., heavy metals, pesticides) taking place in the territory complemented by emission estimates based on modelling. This collection results in a Life Cycle Inventory (LCI) and includes an exhaustive list of environmental pressures resulting from domestic activities. Environmental pressures are then translated into environmental impacts through the implementation of the Environmental Footprint 3.1 (EF reference package 3.1) method in the Life Cycle Impact Assessment (LCIA) stage. The EF 3.1 method includes 16 impact categories, which can be normalized and weighted for their aggregation into a single weighted score. Normalization Factors (NFs) correspond to the EF global NFs, while Weighting Factors (WFs) of the EF weighting set are employed in this study. Finally, the assessment against PBs as absolute ecological thresholds is performed by employing the LCIA-based PBs developed for the EF framework.

The Domestic Footprint is based on the combination of:

1. the emissions to air, soil and water as well as the resources used in the territory;
2. the Environmental Footprint (EF) impact assessment method, which translates emissions and resource consumption into potential environmental impacts.

The Domestic Footprint results from aggregating the environmental impacts of resource use and emissions to the environment in the territory. Resource use and emissions (life cycle inventory) are based either on statistics or on modelling.

The Domestic Footprint results can be reported at different scales:

• At EU level
• At Member States level
• Per environmental pressure (resource use, environmental emission)
• Per environmental impact category (Climate change, Ozone depletion, Particulate matter, Ionising radiation, Photochemical ozone formation, Acidification, Terrestrial Eutrophication, Freshwater Eutrophication, Marine Eutrophication, Freshwater ecotoxicity, Human toxicity (non-cancer), Human toxicity (cancer), Land use, Water use, Resource use (fossils), Resource use (minerals and metals)
• As a single headline indicator (domestic footprint)

The Domestic Footprint has been designed aiming at supporting policy-making in:

• Monitoring: yearly updates of the indicator allow tracking the evolution of impacts associated with changes in production and consumption patterns within Member States boundaries. This may be strategic for monitoring e.g.,:
  • how much the EU is decoupling environmental impacts from economic growth,
  • the benefits of transition towards circular economy,
  • the ability of the EU to remain within planetary boundaries
  • as well as progress related to the UN Sustainable Development Goals (SDGs) (especially SDG12 on responsible consumption and production) (UN, 2015).

• Identification of environmental hotspots: identification of most contributing pressures (emissions or resources) to the environmental impacts e.g. towards reaching environmental targets. This can be performed at multiple levels:
  • elementary flows (resource use, emissions to the environment) to a specific environmental impact,
  • identifying the environmental impacts beyond the planetary boundaries requiring more urgent action.
• Setting a baseline for monitoring and against which testing policy options and scenarios: the Domestic Footprint sets a baseline for monitoring purposes of domestic impacts or for assessing scenarios based on, e.g., modelling exercises, such as expected effect of circular economy on resources use and climate change emissions.

• Agriculture and rural development 
• Climate action 
• Maritime affairs and fisheries 
• Energy 
• Environment 
• Transport 
• Consumers 
• Business and industry 
• Public health 
• Trade