Income inequality and economic complexity impacts on ecological footprint were researched for a panel of twenty-five countries, from 1970 to 2016, using the panel quantile regression approach. Results support that the economic complexity index in the 10th and 25th quantiles and pooled OLS regression positively affects ecological footprint, but not in the 75th and 90th quantiles. Gross Domestic Product in the 10th, 25th, 50th, 75th, and 90th quantiles have a positive effect on ecological footprint. Consumption of fossil fuels and population growth positively affects the ecological footprint in 10th, 25th, 50th, 75th, and 90th quantiles and the pooled OLS. Income inequality in the 10th, 25th, and 50th quantiles and the OLS model regression positively affect ecological footprint. Economic openness in 10th, 25th, 50th, 75th, and 90th quantiles and the pooled OLS negatively affect ecological footprint. Policymakers should promote policies to (i) encourage investment in green energy technologies and implement upgraded energy and environmental laws; (ii) diversify exports and sophisticate products in countries with a high ecological footprint; (iii) depth of human development to control for the population growth and stimulate the economic complexity; (vi) negotiate international trade agreements to open the economy; (v) implement measures to curb income inequality.

The contribution of battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs) to mitigating/reducing fine particulate matter (PM2.5) emissions was researched through a panel of 29 European countries from 2010 to 2019, using the econometric technique of method of moments quantile regression (MM-QR). This research is innovative by connecting the increasing use of electric vehicles with PM2.5 emissions and using the MM-QR to explore this relationship. Two models were estimated to analyse their contribution to reducing PM2.5 in European countries. The nonlinearity of the models were confirmed. The statistical significance of the variables is strong for the upper quantiles (75th and 90th), resulting from the effectiveness of European policies to improve the environment. Electric vehicles (BEVs and PHEVs), economic growth, and urbanisation reduce the PM2.5 problem, but energy intensity and fossil fuel consumption aggravate it. This research sheds light on how policymakers and governments can design proposals to encourage electric vehicle use in European countries. To achieve the long-term climate neutral strategy by 2050, it is imperative to implement effective policies to reduce the consumption of fossil fuels and promote the adoption of electric vehicles using renewable energy sources.

The decarbonisation of the transportation sector is crucial to reducing carbon dioxide (CO₂) emissions. This study analyses evidence from European countries regarding achievement of the European Commission’s goal of achieving carbon neutrality by 2050. Using panel quantile econometric techniques, the impact of battery-electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs) on CO₂ emissions in twenty-nine European Union (EU) countries from 2010–2020 was researched. The results show that BEVs and PHEVs are capable of mitigating CO₂ emissions. However, each type of technology has a different degree of impact, with BEVs being more suited to minimizing CO₂ emissions than PHEVs. We also found a statistically significant impact of economic development (quantile regression results) and energy consumption in increasing the emissions of CO₂ in the EU countries in model estimates for both BEVs and PHEVs. It should be noted that BEVs face challenges, such as the scarcity of minerals for the production of batteries and the increased demand for mineral batteries, which have significant environmental impacts. Therefore, policymakers should adopt environmentally efficient transport that uses clean energy, such as EVs, to reduce the harmful effects on public health and the environment caused by the indiscriminate use of fossil fuels.