Development of a Sankey diagram of material flows in the EU economy based on Eurostat data

Europe relies on reliable and robust knowledge on materials stocks and flows to promote innovation along the entire value chain of raw materials. The concept of the circular economy, recently adopted by the European Commission, aims at maintaining the value of products, materials, and resources in the economy for as long as possible, and minimize waste generation. One of the prerequisites for better monitoring materials use across the whole life-cycle is a good understanding of material stocks and flows. The goal of this report is thus to show how readily available statistical information can be used to generate a Sankey diagram of material flows and their circularity in the 28 member states of the European Union (EU-28).

Despite several data challenges, it is possible to develop a visual representation of material flows and their level of circularity in the EU-28 as well as for individual member states for the period 2004 to 2014 (with future updates possible as new statistical data sets become available). The focus is on non-energy and non-food materials in line with the European Innovation Partnership on Raw Materials (EIP-RM). This includes material flows used for their material quality including, e.g., metals, construction minerals, industrial minerals, and biomass like timber for constructions or fibres for paper or textiles. Materials used for their energy content like fossil fuels, fuel wood, feed or food are excluded. A combination of regularly available data sources including economy-wide material flow accounts (EW-MFA) and EU waste statistics are used to generate a Sankey diagram showing the flows and net additions to stocks of four major material categories (metals, construction minerals, industrial minerals, and biomass (timber and products from biomass)).

In 2014, the turnover of non-energy and non-food materials in the EU economy is found at 4.8 Gt[1] (direct material input + recycling and backfilling). Recycled materials make up around 0.7 Gt (15%) of all materials used in the EU-28 in 2014. Socioeconomic stocks are growing in the EU-28 at about 2.2 to 3.4 Gt each year (net additions to stocks during the period from 2004 to 2014). For example, in 2014 around 51% (2.3/4.5 Gt) of all non-energy and non-food materials used domestically within the EU were added to stocks. Stock accumulation limits the potential for current recovery because material stocks are not immediately available for recycling (but will become available in the future when products providing useful services to the EU economy reach their end-of-life). In 2014, total waste generated from non-energy and non-food materials use in the EU-28 amounted to 2.2 Gt. Some 1.9 Gt of this waste was treated in the EU-28. The largest share of this waste (about 41%) was subject to landfilling operations. About 33% of the waste treated in the EU-28 in 2014 was sent to recycling operations (recovery other than energy recovery and backfilling) and 10% was used in backfilling. The EU is largely self-sufficient for construction minerals and industrial minerals, somewhat import dependent for biomass (for materials purposes), but highly import-dependent for metals.

Sankey diagrams for eight individual member states including Austria, Belgium, Czech Republic, Finland, Spain, France, Germany, and Italy are generated and compared with each other. Overall material throughput is highest for Germany, France, and Italy. Belgium’s economy depends on imports of a large number of raw materials, while several other EU countries domestically produce construction minerals and industrial minerals. Metals are imported by all member states although some EU countries (e.g., Finland) also have limited metal mining activities. In the eight EU member states examined, recycling and backfilling ranges between 11% and 68% at end-of-life (output side) and 6% and 27% when compared to overall material inputs (input side). Germany is used as a case study to show how the proposed visualization framework can be used to generate member state Sankey diagrams for multiple years.

Further research is needed to confirm these findings, fill in data gaps (e.g., trade in waste products), and better estimate selected flow parameters. However, the proposed assessment and visualization do provide a reasonable first picture of raw material uses and their flow magnitudes (by major material categories) in Europe, and how these evolve over time. The resulting Sankey diagrams will feed into the EC’s Raw Material Information System’s (RMIS) MFA module[2] (currently in development) to better visualize related material flows for the EU and at individual country level. The level of circularity can be measured considering different groups of raw materials. Because for materials used for energy purposes materials recovery is mostly not possible, we recommend including resource categories including fossil energy materials and biomass for food and energy purposes in future studies to obtain a more holistic picture of raw materials use in the EU.

Non-energy and non-food material flows in Belgium

The background report with the revised methodology is available from the EU bookshop.

[1] One gigaton (Gt) is equal to 1,000,000,000 metric tons.