The European Union (EU) is one of the strongest, but most complex unions in the world with a competitive tourism industry. The aim of this study, therefore, is to account for economic complexity index (ECI), Brexit and other crisis episodes in the growth-energy-emissions nexus. Theoretically, the traditional Environmental Kuznets Curve (EKC) model is assessed by adopting a One-step System Generalized Method of Moment (Sys GMM) on data for 26 EU member states over the period from 1995 to 2018. For the first time, an EU-macro regional analysis is conducted with and without the UK. Empirical results reveal that an increase in tourism, real GDP per capita, and energy use across the four EU macro regions leads to increase in carbon emission. In some regions, it was observed that tourism, ECI, Brexit, and the Greece bailout have no significant impact on carbon emission. This suggests that the increase in international travel, complexity of the economy, and financial crisis do not accelerate environmental crisis in such regions. However, where such factors are statistically significant, Brexit and the Greece bailout crisis both heighten emissions. Particularly, when the UK is excluded, Brexit and the Greece bailout crisis increase and reduce emissions, respectively. The EKC hypothesis, however, holds in either scenario. Based on these empirical findings, vital policy directions are suggested for a post-Brexit EU-UK energy and environmental relations. • We examined ECI, Brexit and other crisis episodes in the growth-energy-emissions nexus. • An increase in tourism, real GDP per capita, and energy use lead to increase in carbon emission. • In some regions, tourism, ECI, Brexit, and the Greece bailout have no significant impact on carbon emission. • When the UK is excluded, Brexit and the Greece bailout crisis increase and reduce emissions, respectively. [ABSTRACT FROM AUTHOR]