Climate change has expanded beyond a matter of scientific consensus, becoming one of the most contested political issues of our time. How do media networks and digital platforms shape our understanding of the environmental crisis? This book offers a comparative analysis of climate discourse in the United States and Italy, focusing on the ideological divides driving online public opinion and media narratives. Drawing on a mixed-methods approach including topic modeling, qualitative content analysis, and Actor-Network Theory, the author examines how selected progressive and conservative media frame environmental science, activism, and related populist narratives, and how the public reacts to them online. From the highly partisan, anti-elite rhetoric prevalent in the United States to the more technocratic, policy-driven debates in Italy, this study describes how populist narratives and political identities shape the perception of scientific consensus, possibly posing a threat to democratic deliberation. Recommended reading for scholars of political communication and anyone seeking to understand the intersection of science, media, and politics.