Princeton University and University of Oxford researchers found that negative media reports seem to have only a passing effect on public opinion, but that positive stories don't appear to possess much staying power, either. Measured by how often people worldwide scour the Internet for information related to climate change, overall public interest in the topic has steadily waned since 2007. To gauge public interest, the researchers used Google Trends to document the Internet search-engine activity for "global warming" (blue line) and "climate change" (red line) from 2004 to 2013. They examined activity both globally (top) and in the United States (bottom). The numbers on the left indicate how often people looked up each term based on its percentage of the maximum search volume at any given point in time.