The Paris Agreement of 2015, the development of its rules in Katowice and the 2030 Agenda for Sustainable Development demonstrate that there is a political consensus about the relevance of the ecological transition. It implies a decarbonized economy resilient to the effects of climate change and in which nobody is left behind. This transition, which aspires to become a key vector of the economy, has its own rules and legal principles, which have their origin fundamentally in environmental and energy law. For its application and interpretation, our trajectory and experience in reading technically complex regulations places the firm in a privileged position.