Have we reached a “tipping point” in climate change reporting? How mainstream newspapers cover heatwaves

This paper investigates the evolution of media coverage on heatwaves from 2010 to 2022 focusing on six countries (UK, USA, India, Australia, Canada, and China) through analysis of 27,964 newspaper reports. By employing content analysis and named entity recognition, we examine the volume of heatwave-related reports, their connection to climate change, and the incorporation of environmental science within media narratives. We explain our findings with reference to the concept of a dynamic or mobile public sphere. We identify three types of diffusion in the reporting of climate change in public spheres, which we term temporal diffusion, geographical diffusion, and political diffusion. These concepts illustrate the spread of ideas across time, space, and ideology. These shifts are characterised by an escalating media focus on heatwaves over time and the increasing association between heatwaves and anthropogenic climate change, a diffusion from countries in the Global North to the Global South, and a broadening attention from predominantly left-wing media across a wider ideological spectrum. This study contributes to our understanding of how journalistic practice, accumulated media attention, and environmental science can lead to significant shifts in transnationally linked public spheres, encouraging broader societal recognition of and engagement with climate change issues.