Co2 Emisyonlarını Etkileyen Faktörlerin Zamanla Değişen Katsayılı Parametrik Olmayan Panel Veri Modelleri ile Analizi

Carbon dioxide (CO2) emissions and other greenhouse gases are one of the reasons for climate change, global warming, and environmental degradation. CO2 is distributed throughout the Earth’s surface by human activity and is often harmful to the environment by causing climate change (i.e., global warming). Therefore, the literature has examined many economic and noneconomic social factors that affect CO2 emissions. However, most studies, have ignored the economic uncertainty regarding CO2 emissions effects on main factors such as economic growth and energy use. This study, discusses the relationships per capita CO2 emissions has with other variables, especially economic uncertainty as measured by the World Uncertainty Index. This article examines the relationship by utilizing the data for 14 OECD countries between 2000-2021 using a non-parametric panel data model with time-varying coefficients. By estimating trend functions and nonparametric coefficient functions, the study’s results show nonparametric coefficient functions on CO2 emissions to vary with time. In terms of signs and significance, the nonparametric coefficient function for economic uncertainty had a significant negative effect over the 2000-2021 period. In addition, economic uncertainty sustained a negative impact over time. The signs for nonparametric coefficients regarding GDP per capita, population, and renewable energy were seen to fluctuate, alternating between negative and positive values over time. Although trade was insignificant during the early 2000s, it became a significant variable between 2009-2013, while having no significant sustained effect in 2021.