To combine the teaching of scientific concepts with the challenging problems of socioscientific issues (SSI) has been shown to be effective on engaging students in discussions and in developing students’ skills in decision-making and critical thinking. Research has revealed that teaching SSI in science education is a challenging task for science teachers alone suggesting a co-operation with teachers of the humanities, proposing that these teachers might be better at managing debates and other pedagogical methods related to a SSI driven instruction. However, to our knowledge no one has yet investigated the outcomes of a co-operation between language teachers, who regularly in their courses teach topics like argumentation, debate and how to write an argumentative text, and science teachers. Hence, the aim of our study is to investigate how the co-operation of teachers from different disciplines (language and science teachers) can contribute to upper secondary school students’ argumentation skills about global warming. A total of ten teachers from the subjects of Swedish (mother tongue), English, biology, physics and chemistry will participate in this study together with two classes of science major students in their first year of upper secondary school, which they teach. Data will be collected from both the teachers by interviews at the end of the teaching sequence and from students making a pre- and post-test of written argumentation about global warming, as well as interviews. Since this study is an ongoing project, we are still collecting data. We foresee that we will find that the teachers as well as the students can provide us with insights on how they perceive a cross-disciplinary teaching with focus on SSI, and also that we will be able to follow some progression in students argumentation through the pre- and post-test. Our findings on the learning outcome and how teachers and students perceive a cross-disciplinary teachers’ cooperation on SSI will be presented at the ERIDOB-conference. We believe that the results from our study will provide valuable insights on how to develop future SSI-teaching by using a cross-disciplinary approach and how the involvement of language teachers may be of help to the science teachers in doing this.