Engaging the public with the climate crisis has proven challenging due to both the technical complexity of the issue and the strong emotions evoked. “Doom and gloom” approaches run the risk of provoking backlash, despair or overwhelm, none of which support constructive action. Here we used unscripted theatre to make room for both scientific content and affective responses, towards enhancing agency in rural communities at the greatest risk of negative impacts from climate change, who are often excluded from scientific, engagement, and policy discussions. We developed a travelling improvised theatre show called ‘We Built This City on Rock and Coal’ that toured diverse Irish coastal and island communities. Mixed methods evaluation showed that self-efficacy of improvisers, scientists, and audience members on the topic of climate change increased after taking part, demonstrating the viability of improvised theatre as a science communication strategy and methodology for co-created engagement with societal challenges.