What 'Eco-Unions in the Transition towards a Low Carbon Economy’ is a comparative, interdisciplinary and mixed methods study that will explore and seek to explain (a) how trade unions approach the “jobs versus environment” dilemma in their policies, discourses and initiatives; (b) how organisational and institutional dynamics shape and condition their transformative scope, and (c) what role trade unions play in public debate on the transition towards a low carbon economy. Why Tackling the global crisis of human-induced climate change is the most urgent and immense challenge of the twenty-first century. To help achieve this, the European Union has subscribed to the Paris Agreement and the 17 Sustainable Development Goals of the UN. Trade unions have a crucial role to play in implementing these measures since the most significant impact on climate change will be through a transformation of industrial production. However, trade union action is limited by a “jobs versus environment” dilemma between protecting the environment and protecting jobs in polluting industries which millions of workers depend on for their livelihood. This research project provides much-needed new knowledge on how trade unions in different European countries are navigating this dilemma. How Eco-Unions combines a mix of in-depth interviews, documentary and content analysis with digital methods that fit the multi-level structure of the project. The empirical analysis focuses on the largest and most influential general trade unions in each country with members across all sectors of the economy. It is structured along three mutually informing levels of analysis. The organisational level is focused on how union strategizing is shaped by internal contestation between union officials representing different sectors of the economy. The institutional level is focused on trade union involvement in climate policy formation. Finally, the societal level is focused on the role of trade unions in public debate on the transition to a low carbon economy. SSR The project will provide knowledge into the conditions under which truly transformative trade unions can flourish to help the EU and its member states meet their commitments to the Paris Agreement and the UN Sustainable Development Goals.