We show that this acceleration, which took off in 2002, was not a short-term phenomenon but continues since more than a decade. Our results indicate a significant acceleration of global material flows since the beginning of the 21st century.
In 2015, outflows amounted to 58 Gt/yr, of which 35% were solid wastes and 25% emissions, the reminder being excrements, dissipative use and water vapor. Since materials increasingly accumulate in stocks, outflows of wastes are growing at a slower pace than inputs. A shift from materials for dissipative use to stock building materials resulted in a massive increase of in-use stocks of materials to 961 Gt in 2015. Over the whole time period, we observe a growth in global material extraction by a factor of 12 to 89 Gt/yr.
This enables outlooks on inflows and outflows, which environmental policy makers require for pursuing strategies towards a more sustainable resource use. Based on this approach, we can trace materials from extraction to their use, their accumulation in in-use stocks and finally to outflows of wastes and emissions and provide a comprehensive picture of the evolution of societies metabolism during global industrialization. In this article, we provide a consistent assessment of the development of material flows through the global economy in the period 1900–2015 using material flow accounting in combination with results from dynamic stock-flow modelling. The size and structure of the socioeconomic metabolism are key for the planet’s sustainability.
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