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 effect of materials becomes highly crucial, especially from the climate mitigation perspective. However, its effect 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 first decompose CO2 emissions into four effects based on the two different model specifications (materials and energy models). We secondly determine the impact decoupling status and efforts of countries with two different approaches: Tapio-based decoupling elasticity (TAPIO) and decoupling effort index (DEI). Our LMDI and TAPIO results show that material and energy-related efficiency effects 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, developing countries need to further improve their mitigation efforts. Designing and implementing some policies only centering energy/material intensity or carbon intensity of energy might not be sufficient to achieve the decoupling. Both energy- and material-related strategies should be considered in harmony.

Decomposition and decoupling analysis of energy-related carbon emissions in Turkey.

This study focuses on CO2 emission trends and its decompositions as well as decoupling performance between CO2 emissions and economic growth of Turkish case for the period of 1990-2016. The drivers of CO2 emission changes are calculated by using an extended Kaya identity and the well-established logarithmic mean Divisia index (LMDI) method. Decomposition results indicate that economic growth and population effects are the main driving forces in increases in carbon emissions in Turkey throughout the whole period, while other technology-based driving factors' impacts have been rather minimal in reducing the emissions. Decoupling analysis results demonstrate that there is either no decoupling or weak decoupling in most of the years. Moreover, total decoupling effort index suggests that Turkey's performance has been worsened in recent years as we found no decoupling between CO2 emissions and economic growth over the period of 2013-2016. The overall findings suggest that Turkish economic growth is unsustainable both environmentally and economically. Based on these findings, some policy implications and recommendations are discussed for the possible emission reductions.

How production-based and consumption-based emissions accounting systems change climate policy analysis: the case of CO2 convergence.

Much of the existing research analyses on emissions and climate policy are dominantly based on emissions data provided by production-based accounting (PBA) system. However, PBA provides an incomplete picture of driving forces behind these emission changes and impact of global trade on emissions, simply by neglecting the environmental impacts of consumption. To remedy this problem, several studies propose to consider national emissions calculated by consumption-based accounting (CBA) systems in greenhouse gas (GHG) assessments for progress and comparisons among the countries. In this article, we question the relevance of PBA's dominance. To this end, we, firstly, try to assess and compare PBA with CBA adopted in greenhouse gas emissions accounting systems in climate change debates on several issues and to discuss the policy implications of the choice of approach. Secondly, we investigate the convergence patterns in production-based and consumption-based emissions in 35 Annex B countries for the period between 1990 and 2015. This study, for the first time, puts all these arguments together and discusses possible outcomes of convergence analysis by employing both the production- and consumption-based CO2 per capita emissions data. The empirical results found some important conclusions which challenge most of the existing CO2 convergence studies.