Since 1972, environmental education and sustainable development (ESDD) has been recognized as a powerful lever for changing attitudes and behaviour and enabling societies to make an ecological and inclusive transition (objectives 4 and 4.7 of the 17 Sustainable Development Goals for Agenda 2030, UN).At the time of the UN World Climate Summit in September 2019, we are in urgent need of action.The world of ESD education is very diverse in Europe, supported by several types of institutions and structures with actors with very different professions, functions and status, ranging from voluntary action to higher education. They work in the field with a variety of audiences. The professional sector of EESD is still young, self-organized, with a training offer that is being structured. Our ETRES European Educational & Training Resources for Environment & Sustainability project brings together partners involved in EESD training: an association combining EESD research and training (IFREE and Montpellier SupAgro), a regional network of professional EESD actors (GRAINE Occitanie association), an international network of EESD actors based in Greece (Polis NGO), a social cooperative bringing together social workers committed to sustainable development: Social cooperative Alchimia in Italy, a training centre ed EEDD located in a regional natural park (Area Parchi Lombardia - Parco Nord Milano Italy), and a Spanish company specializing in communication on the environment (Tekieroverde).Our main objective is to contribute to the professionalization of ESD actors in Europe and in our respective countries. More specifically, we have worked to highlight an emerging function for these actors and in our territories: the support of the ecological transition through citizen dynamics. With regard to this new function, our objective was to set up an online training platform and integrated training systems in the networks of EESD actors in our different territories.In our four countries, we have highlighted the outlines of this new support function. We have drawn up a reference framework of key activities with the actors in the field. We have developed educational resources in the form of fact sheets and videos to illustrate key situations and activities and provide theoretical, methodological and practical elements for the training and self-training of EESD practitioners in line with the skills needed in the field.ETRES is currently an online training platform (https://etreserasmus.eu/), free of rights, translated into four languages, structured in the form of five modules containing about sixty downloadable educational resources formatted and presented in a pedagogical booklet facilitating their use for training structures and actors in self-training.ETRES is now integrated into about ten training systems in the four countries of the partnership, under various modalities: within professional continuing training, initial training formally validating the acquired skills (certificate, ECTS, digital badges). Two digital badges highlight the skills of accompanying practitioners and trainers who are familiar with ETRES tools.ETRES is a territorial and European dynamic bringing together actors committed to supporting the ecological transition through citizen dynamics: the main ESD networks of the four countries are mobilized and about twenty referents and relays are identified on the ETRES website. The animation of an ETRES dynamic is planned until 2021.The organizations participating in the project have all developed expertise on the issue of supporting the ecological transition through citizen dynamics and on pedagogical engineering in a European context.We have created training and reflection processes within our countries and we have been able to reactivate a network of exchanges and mutualisation on these issues at European level.We have already trained about a hundred EESD actors whose acquired skills are valued in the form of certificates, ECTS credits or digital badges. We have carried out about ten participatory events and many meetings in order to disseminate ETRES in our territories.The scheme, which gradually involves new participants, will be presented in Bangkok at the World Environmental Education Network (WEEC) Summit from 3 to 7 November 2019.