In ten years, the union movement`s perception of environmental challenges has evolved and, with it, the definition, limits and scale of the necessary “just transition”. Today, the “just transition” can be understood as the conceptual framework within which the labor movement seizes the complexity of the transition to a low-carbon, climate-resilient economy, highlights the needs of public policies, and aims to maximize the benefits and minimize the hardships for workers and their communities in this transformation. Supporting workers in their efforts to acquire skills that enable them to preserve better and more sustainable jobs is the key to creating an electorate to fight climate change. It is essential to ensure the adequacy of skills development portfolios, which are obsolete in many countries or do not correspond to the opportunities offered by the labour market. The term “just transition” was first coined in the 1990s by North American unions to describe a system of support for unemployed workers due to environmental protection measures.  The concept can be seen as an ecological application of the economic conversion developed in the 1980s, when anti-war militants attempted to form a coalition with military workers and give them a share of the peace economy. The European Union has adopted Just Transition as an important part of its European Green Deal to help fossil fuel-dependent regions of the European Union transition to a greener economy. .