The turning points of carbon Kuznets curve: Evidences from panel and time-series data of 164 countries

With the dramatic economic development, global warming caused by carbon emission has become increasingly serious, and carbon emission reduction therefore comes to be the principle in most countries. Turning point (TP), which represents carbon emission turns from increasing to decreasing tendency with the economic growth, has become a major focus of political and academic concern. However, previous studies on TP were contextualized only in individual countries or regions but barely from a global perspective, which are insufficient for solving the carbon emission as a global issue. Therefore, this study aims to provide a global picture of the carbon emissions by identifying the TPs of 164 countries and five panel groups (i.e. global, high-income, upper-middle-income, lower-middle-income and low-income levels) in the world and the patterns of them. The results show that 123 individual countries and all the five panel groups accept the carbon Kuznets curve (CKC) hypothesis. Then, the TPs of them are identified. In particular, three close correlations are identified throughout the study: (1) the proportion of the CKC hypothesis and income level, i.e., the higher income level, the larger proportion of countries meeting the CKC hypothesis; (2) the TPs and income level, i.e., the higher income level, the higher TP; and (3) the turning years and income level, i.e., the higher income level, the shorter turning years. The identified TPs in this study provide valuable references for not only individual countries but also countries at different income levels to tailor their strategies and policies to finally achieve global carbon emission reduction.