Climate change is one of the most critical challenges of the twenty-first century. Public understanding of climate issues and of the goals regarding the climate transition is essential to translate awareness into concrete actions. In this context, social media platforms play a crucial role in disseminating information about climate change and climate policy. To better understand the dynamics of information circulation and the emergence of information voids we propose a model that takes into account the supply and demand of information related to the Italian climate-transition discourse. We conceptualise information supply as the production of content on Facebook, Instagram and GDELT (an online news database) while leveraging Google searches to capture information demand. Our findings highlight responsiveness and temporal coupling between supply and demand, particularly during moments of heightened public attention triggered by significant external events. These responsive interactions reveal an overall adaptive information ecosystem. However, we also observe persistent information voids which may limit public understanding and delay meaningful engagement.