This paper demonstrates that information systems (IS) researchers and practitioners can make a significant contribution to the grand challenge of sustainability in light of global climate change. In doing so, the paper takes a novel perspective by going beyond the dominant emphasis in the Green IS literature on climate change mitigation to focus on climate change adaptation. To demonstrate how IS researchers and practitioners can engage with the grand challenge of sustainability, we report the findings of an investigation into the role of IS in climate change adaptation programmes of the government of New South Wales, Australia. Canonical action research, informed by activity theory, proved to be an appropriate methodology for this investigation by combining iterative collaborative engagement and rigorous scholarly reflection. Activity theory has previously been successfully used in IS research as a framework for inquiry and description but not for prediction. This raised questions, addressed in this study, about whether or not activity theory could be used to guide interventions and make sense of their impact. The findings reveal how activity theory provides an appropriate balance between scope and detail to accommodate the complex processes of planning and implementing climate change adaptation programmes. We conclude that while climate adaptation is complex, activity theory, specifically five dynamic dimensions for deep sense‐making, can inform interventions in climate change adaptation projects. Most significantly, we demonstrate that IS experts can make a positive contribution to addressing one of the most important grand challenges of our time.