The relationship between fossil fuel CO2 emissions and economic growth in the Visegrád (V4) countries (Czechia, Hungary, Poland, and Slovakia) is examined through the lens of the environmental Kuznets curve (EKC) hypothesis. Employing the modified environmental Kuznets curve (MEKC) hypothesis, time-series data from 2010 to 2022 were analyzed. The methodology encompasses a range of econometric techniques, including temporal, comparative, correlational, and regression analyses, to unravel the intricate relationship between economic development (measured by GDP per capita) and environmental pollution (CO2 emissions). Results reveal a complex nonlinear correlation between GDP per capita and CO2 emissions in the V4 countries, following an inverted U-shaped pattern. Specifically, Czechia and Hungary exhibited peak emissions at approximately USD 5000 and USD 4500 GDP per capita, respectively, with corresponding emission levels of 1.15 and 0.64 metric tons. In contrast, Slovakia’s emissions decreased after its GDP per capita exceeded USD 5000 and carbon dioxide emissions reached 0.15 metric tons. However, Poland’s data deviate from the MEKC pattern, exhibiting a consistent rise in CO2 emissions across all levels of GDP per capita. The study highlights that the power industry is the largest source of CO2 emissions in all four countries, contributing 88.09% of total emissions. The transportation and industrial combustion sectors account for about 2.12% and 1.28% of annual emissions, respectively. GDP–CO2 emission correlations vary across the V4 countries. While Czechia exhibits a positive correlation of 0.35, Hungary (−0.37), Poland (−0.21), and Slovakia (−0.11) display negative relationships. Notably, Poland experiences the most significant increase in CO2 emissions from both road transport and air traffic. The conclusions drawn from this study provide a robust foundation for developing tailored environmental policies that support sustainable growth in the Visegrád region and other transitioning economies.
