DEFINE-MATTER is a simplified module of DEFINE that shows how economic activity leads to the extraction of matter and the generation of waste. A brief description of the DEFINE-MATTER module is available is available here. The R code of the module can be downloaded here. This web interface allows you to use DEFINE-MATTER to explore how the use of matter and the generation of waste are affected by the following key factors:

• The rate of economic growth after 2022. With everything else given, the higher the rate of growth the higher the use of matter and the higher the generation of waste. The default value is 2.9%.

• The recycling rate after 2022. An increase in this rate has a favourable effect on the use of matter and the generation of waste, since it permits the production of goods and services by relying more on already used matter and less on the extraction of new matter. The default value is 27% which is close to the current rate of recycling.

• The material intensity after 2022. This is defined as the use of matter (in gigatonnes) per GDP (in trillion US$, 2018 prices). The higher the level of material intensity the more adverse the impact of economic activity on material depletion and the generation of waste. The default value is 0.61 gigatonnes per US$ trillion , which is close to the current level of material intensity.

Note: If the material depletion ratio becomes higher than 1, this means that the global economy has exhausted all its material reserves, thus further economic expansion is not possible. This is not reflected in this interface, since the module does not include the feedback effects of matter depletion (as well as of waste generation) on economic growth. These effects are incorporated in DEFINE, but have been assumed away in the interface for simplification purposes.