As the world’s population continues to increase, there are two topics which are becoming important for teachers to include in classroom studies: bilingualism/multilingualism (foreign language acquisition) and environmental awareness (Environmental Education for Sustainable Development). ‘Green Immersion’ (GI), which originated in the EU-funded ELIAS project, combines both topics into one educational session. GI teaches young children the fundamentals of environmental education (the combination of ecology, sociology, economics, culture) while using the foreign language as the language of communication. This course covers the theoretical and practical themes of GI. Beginning with the theoretical, the course will cover principles of language acquisition in young children and how these apply to Green Immersion, and then continue with the origins and application of Environmental Education for Sustainable Development (ESD), and how a ‘non-scientific’ teacher can incorporate this knowledge into the Sachunterricht, natural sciences or EFL classroom, promoting cross-curricular learning. Then finally, this course will cover how to effectively combine language acquisition and ESD into one session, through the use of teaching materials and methods. This final section of the course will include practical experiences and work on acquiring, creating and delivering Green Immersion sessions. The objective of this course is to prepare foreign language educators for using GI sessions in the classroom, by equipping them with theoretical knowledge and the creation of their own GI teaching material portfolio.