Stacy Rebich Hespanha* - National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara
Joao Hespanha - Department of Electrical and Computer Engineering, University of California, Santa Barbara
Ronald E. Rice - Department of Communication, University of California, Santa Barbara
Daniel R. Montello - Department of Geography, University of California, Santa Barbara
Stephanie E. Hampton - National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara
The US news media has been delivering information about global warming and climate change to the public since the early 1970s, yet the link between news coverage and public awareness of and knowledge about the issue is anything but clear. Crucial to characterizing that link is a better understanding of what the news media actually covers, and how. Our study takes a first step toward elucidating connections between US news content and public understanding by creating a detailed picture of the individuals, institutions, concepts, locations, and processes that have garnered climate-related media coverage over the past four decades. Data for the study include more than 100,000 newspaper and magazine articles, television and radio transcripts and weblogs from major news outlets. A statistical topic modeling algorithm (Latent Dirichlet Analysis) was used to extract most probable themes for each news story, and dimensionality reduction and network analysis approaches were used to identify thematic and temporal patterns. Building upon the results of this text mining approach, we propose a set of broad themes that have been used to frame US news about climate change and examine how emergence and development of these themes may relate to political and cultural events, weather phenomena, business and economic conditions, and news media dynamics.