Energy and climate change are salient topics in the external relations of the European Union (EU) and its individual Member States. Both energy and climate are policy areas falling under the scope of ‘shared competences’. The Treaties, however, do not stipulate external competences. As a result, the ‘shared external competences’ in energy and climate change generate different effects in practice. This is partly due to substance: climate action constitutes a global common goods challenge, whereas energy security is more of a national concern, largely being demarcated by Member State sovereignty. There are also important ‘trade-offs’ and linkages between these two areas. Institutionally, differences exist, since there is a universal (Paris) agreement on climate change mitigation, while such an agreement is absent in the areas of global energy (security). Future research should aim to combine the analysis of EU and Member State external action on energy and climate change, as these agendas are aligned and sometimes respective policy avenues contradict each other. Furthermore, research could focus on the effects of other actors, such as the private sector, local authorities, populist parties or major third parties, such as Russia, on the external policies, institutional framework and global scope of the actions of the EU.