Understanding material and energy use in the processes of decoupling CO2 emissions from economic growth

The share of emissions from materials has dramatically increased over the last decades and is projected to rise in the coming
years. Therefore, understanding the environmental efect of materials becomes highly crucial, especially from the climate
mitigation perspective. However, its efect on emissions is often overlooked and more attention is heavily paid to the energy
related policies. In this study, to address this shortcoming, we investigate the role of materials on the decoupling of carbon
dioxide emissions (CO2) from economic growth and compare it with the role of energy use in the world's top-19 emitting
countries for the 1990–2019 period. Methodologically, using the logarithmic mean divisia index (LMDI) approach, we frst
decompose CO2 emissions into four efects based on the two diferent model specifcations (materials and energy models).
We secondly determine the impact decoupling status and eforts of countries with two diferent approaches: Tapio-based
decoupling elasticity (TAPIO) and decoupling efort index (DEI). Our LMDI and TAPIO results show that material and
energy-related efciency efects have an inhibitory factor. However, the carbon intensity of materials has not contributed
to CO2 emissions reduction and impact decoupling as much as the carbon intensity of energy has. DEI results indicate that
while developed countries make relatively good progress towards decoupling, particularly after the Paris Agreement, devel
oping countries need to further improve their mitigation eforts. Designing and implementing some policies only centering
energy/material intensity or carbon intensity of energy might not be sufcient to achieve the decoupling. Both energy- and
material-related strategies should be considered in harmony.