The role of material production as a driver of environmental impacts is increasing, which calls for a better understanding of global material flows. This thesis explores the role of in-use stocks... Show moreThe role of material production as a driver of environmental impacts is increasing, which calls for a better understanding of global material flows. This thesis explores the role of in-use stocks of products, buildings and infrastructure as a key driver of global material demand and discusses the implications with regards to availability of waste flows. The method based on detailed product compositions and lifetimes is applied to generate material use scenario’s towards 2050 for appliances, vehicles, buildings and electricity infrastructure. Under most of the developed scenarios, a growing population and increasing affluence are expected to lead to higher demand for products, and consequentially leads to a continued growth in annual material demand worldwide. While the results can be used to identify sector specific challenges and opportunities for achieving a more circular economy, the method also provides a starting point to incorporate material cycles and resource efficiency strategies more explicitly and consistently in integrated assessment models. This would allow for a more comprehensive assessment of resource use in relation to other global challenges such as climate change. Show less
To limit the effects of climate change, global average temperature since pre-industrial measurements are to be kept well below 2 °C preferably even at 1.5 °C. The 2 °C limit and certainly the... Show moreTo limit the effects of climate change, global average temperature since pre-industrial measurements are to be kept well below 2 °C preferably even at 1.5 °C. The 2 °C limit and certainly the 1.5 °C target means that substantial GHG emission reductions should be realized already by 2050. How these emission reductions should be achieved is unclear. At least it is clear that the use of fossil fuels should be reduced. It is important to know if indeed the introduction of the renewable energy technologies can achieve the deep GHG emission reduction that are required in 30 years’ time against a backdrop of population growth and economic growth. Therefore we investigated the effects of the introduction of renewable technologies on GHG emissions and resource use until 2050. The principal global economy-environment model used in this investigation is based on a global multi-regional environmentally extended input-output framework which might be called a structural economic model. Because long-term socio-economic and technological developments cannot be predicted several scenarios with different penetration rates of low carbon and renewable energy technologies and resulting GHG emissions and resource use have been implemented in the structural economic model. Show less
