What happens to researchers when the topic they study poses an existential threat to the world as we know it? When communication on the topic is politically polarized, but at the same time institutionally encouraged and existentially needed? By what means do researchers come to navigate this complex communication environment? The climate crisis and changing social, political, and academic conditions bring such questions to the forefront in researchers’ public communication on climate issues. This thesis engages with open letters as a form of research communication to explore the practices climate scholars engage in to convey information and inspire urgent action in climate matters. Contrary to views of open letters as political opinion pieces used for popular mobilization, this dissertation explores their multifaceted roles through a variety of information and communication practices. The thesis illustrates how open letters provide a space to contemplate one’s role as an academic in the climate crisis, emphasizing the transformative and constitutive potential of communication as practice. Moreover, researchers’ practices and engagement in open letters on climate change also contribute to reconceptualizing the notion of mobilization, thus expanding the breadth and understanding of how information is put into action.