• This chapter examines the high-impact experiences of project-based language learning (PBLL) as a curricular framework for deep learning about human and ecological sustainability. As a form of content-based instruction, it not only opens students to a broader way of thinking about and valuing the power of language and culture to inform, but also offers the opportunity to change perspectives and behaviors thus facilitating student intellectual and emotional growth. This chapter includes a brief overview of a 3rd-year college-level PBLL Chinese language course on climate action, which addresses the multilingual and multicultural dimensions of climate change. This approach teaches students that other cultures see their relationship to nature and the environment differently, and the language they use to speak about these relationships has the potential to open a multitude of perspectives for seeking solutions to our current climate and humanitarian crises.