Driving forces of CO2 emissions in the G20 countries: An index decomposition analysis from 1971 to 2010

The G20, a grouping of the largest developed and developing economies in the world, accounts for almost 86% of global Gross Domestic Product and 76% of global CO2 emissions. In recent years, the G20 global summit has not only aimed to support an economic agenda, but also to coordinate actions towards a cleaner energy and low-carbon future. However, in different countries driving forces for the change in CO2 emissions may vary due to being at different stages in their development and being on different development pathways. Due to their increasing share in global greenhouse gas emissions, emerging economies are likely to play a more important role in the future to promote multi-level cooperation on key issues, especially in mitigating climate change. Therefore, a better understanding of driving forces of each country's change in CO2 emissions is essential to tackle global climate change and to develop a broadly acceptable agenda for climate change mitigation. Using index decomposition analysis, this study aims to identify the main driving forces of CO2 emissions in the G20 countries.The results show that the driving forces of CO2 emissions are significantly different in advanced economies versus emerging economies. In general, economic growth was the main factor for increasing CO2 emissions. Apart from economic growth, population growth shows the strongest effect on CO2 emission growth in the emerging economies such as Mexico, South Africa, Brazil, Turkey, and Argentina. This growth in emissions was partly compensated by improved energy efficiency and reduced carbon intensity in most advanced economies and some emerging economies, whereas in other G20 countries, such as France, Brazil, Mexico, South Africa, and Saudi Arabia, energy intensity was increasing. Our results imply that different countries require different policies to do justice to the differences in trajectories and factors influencing CO2 emissions.