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Despite the intrinsic differences of the two approaches, the results converged in the description of an overall absolute decoupling of the Consumption Footprints Top-down and Bottom-up from indicators of economic growth, such as GDP and Final Consumption Expenditure (FCE). However, the extent is different depending on the approach. The Trade Footprints show a deviation from the economic value of imports and exports in both approaches (Figure 31). The comparison between the temporal trends is done considering years between 2005 and 2014 for the reasons explained in section 3.3.1 and because results for the bottom-up approach in 2004 are interpolated (see section 3.4.1).

As highlighted in section 3.3.2, the Consumption Footprint Top-down, which was relatively stable within 2005 to 2014, highlights a decoupling of GDP and FCE from environmental impacts, which raised respectively by 8% and 7%. The Consumption Footprint Bottom-up, instead, decreased by 23% and showed an absolute decoupling, aligned with the decrease of the Domestic Material Consumption (DMC), measuring the total amount of materials directly used by an economy. Such divergences rely on the different methodological approaches, which add uncertainty in measuring the decoupling. While the top-down approach is based on economic data from Multi-Regional Input-Output Tables, the bottom- up approach uses process-based LCA for assessing individual products and up-scale the impact according to mass volumes.

The gap between the Consumption Footprints Top-down and Bottom-up is justified by the higher differences in absolute values between Trade Footprints Bottom-up and Top-down, (Figure 32). In other words, this means that import plays a considerable influence in the Consumption Footprint Top-down (the ratio between Import and Consumption Footprints is between 84% and 108% depending on the years), which is not the case of the Consumption Footprint Bottom-up, having a ratio between Import and Consumption Footprint comprised between 32% and 38%. Beneficial to the negative trend of Consumption Footprint Bottom-up are the concomitant reduction of the Domestic Footprint (-19%), the reduction of the Import Footprint Bottom-up (-5%), and the considerable increase of the Export Footprint Bottom-up (+27%) (“export effect”).

Figure 31. Temporal trends (2005-2014) of Trade and Consumption Footprint Top-down and Bottom-up, and economic figures (GDP, FCE, RME).

Note. Ec. value=Economic value; GDP=Gross Domestic Product; FCE=Final Consumption Expenditure; RME= Raw Material Equivalents; DMC=Domestic Material Consumption. (Sources: Eurostat, JRC analysis). Bottom-up footprints are calculated for 2005, 2010, and 2014, whereas the other years are interpolated.

The Import Footprint Top-down follows the trend of the economic value of imported products, although a relative deviation happens, since the economic value increases more (+43%) than the Export Footprint Top-down (+29%). The Import Footprint Bottom-up, instead, has a decreasing trend (-5%) very similar to the mass of imported products (- 6%), opposite to the increasing trend of the economic value. The Raw Material Equivalents (RME), which describes the amount of raw materials embodied in imports over the whole production chain, increased by 8% despite an overall reduction of the mass of imports. The Export Footprints, the indicators related to mass and resources embedded in exported products (RME), and the economic figures related to export highlight a considerable increasing trend from 2005 to 2014. A partial deviation from the trend of the economic value of exported products, which increase by 62%, is found both with the top-down and the bottom-up approaches, although the extent of the deviation is different: the Export Footprint Top-down increases by 40%, whereas the Export Footprint Bottom-up increases by 27%. Overall, the top-down approach brings to a higher estimation of the impacts, compared to the bottom-up. Possible reasons for this difference may be the broader objective of the top-down approach, which includes services and governments, intrinsic differences in the way the inventories are calculated with the two approaches, and potential overestimation of the impact on mineral resource use, which has a considerable influence on the Consumption Footprint Top-down (see section 3.3.1 for details).

The bottom-up approach is in general closer to the trend expressed in mass of products, e.g. Consumption Footprint Bottom-up and DMC, and Trade Footprints Bottom-up and

70% 75% 80% 85% 90% 95% 100% 105% 110% 2 0 0 5 2 0 0 6 2 0 0 7 2 0 0 8 2 0 0 9 2 0 1 0 2 0 1 1 2 0 1 2 2 0 1 3 2 0 1 4 Apparent consumption GDP +8% FCE +7% Consumption Footprint Top-down 0% Consumption Footprint B-up -23% DMC -17% Import Export 60% 80% 100% 120% 140% 160% 180% Ec. value Mass Trade Footprint Top-down Trade Footprint B-up RME 60% 80% 100% 120% 140% 160% 180% +43% -6% +29% -5% +8% +62% +33% +40% +27% +35% Domestic Footprint -19%

mass of imported/exported products. In contrast, the top-down approach is more similar to the trends of economic indicators, e.g. Consumption Footprint Top-down and GDP or Final Consumption Expenditure (FCE), Trade Footprints Top-down and economic value of imported/exported products. This divergence may rely on the different scope of the two approaches, namely the fact that the top-down approach accounts for elements, e.g. services, which do not have any mass but have an economic value, which are instead omitted in the bottom-up approach. The increase in the indicator related to resource use, the RME, is in case of both imports and exports, between the increase of the mass of products and the economic value.

Further refinements of the modelling in both bottom-up and top-down approaches would be beneficial for a more in-depth analysis of the extent of decoupling at EU level. From a bottom-up perspective, an option to improve the account would be to include selection criteria for products based on environmental relevance as reported by Lavers et al. (2017), to increase the number of representative products and to refine life cycle inventories for representative products (Box 6). For the top-down approach, a broader coverage of elementary flows and, at the same time, a higher disaggregation of flows, would guarantee a more adequate assessment of impacts.

Figure 32. Import, Export and Consumption Footprints.