The dependence on fossil fuels, which are still re-sponsible for the majority of the greenhouse gas emissionsof humanity, is a strong driver for global climate change.Circular economy, which includes the reuse and repair ofproducts and the recycling of materials, can contribute sig-nificantly to a reduction of the CO2footprint of materialsand products. In this paper, potentials for the reduction ofgreenhouse gas emissions, mainly in the material systemsof steel, aluminium and plastics, are shown and analyzed.