“To capture politicization, the researchers looked at how often those articles mentioned Republicans, Democrats and scientists. This allowed for a comparison over time between different environmental issues. In the 1980s and 1990s, there were more mentions of scientists thanpoliticians in climate change coverage, but this trend changed in the 2000s as politicians were cited more often.”
https://m.phys.org/news/2020-03-polarization-climate-news-hoax.html