This paper reports on a study that was undertaken to contribute to knowledge of learning and teaching of sustainable development in relation to global contexts. To better understand how transdisciplinary teaching of education for global learning of sustainable development (GLSD) becomes subject to different conceptualizations and approaches, variations in how different subject area teachers experienced collaborative ESD were analyzed and described. To achieve this, the study utilized a phenomenographic approach with semi-structured interviews to investigate the teaching of GLSD among 12 teachers at an upper secondary school in Sweden (2010–2011), who engaged with transdisciplinary planning teaching for sustainable development with a global focus. Findings from these interviews showed the value of awareness raising dialogues among teachers and the importance of mutual development of content and approaches to ESD. This presentation will describe the study and outcomes, and outline five main teaching attitudes (critical; supportive; complementing; cogent; and respectively persuasive) that were identified among the teacher approaches of transdisciplinary teaching for GLSD.