Despite concerns about politicization and polarization in climate change news, previous work has not been able to offer evidence concerning long-term trends. Using computer-assisted content analyses of all climate change articles from major newspapers in the United States between 1985 and 2017, we find that media representations of climate change have become (a) increasingly politicized, whereby political actors are increasingly featured and scientific actors less so and (b) increasingly polarized, in that Democratic and Republican discourses are markedly different. These findings parallel trends in U.S. public opinion, pointing to these features of news coverage as polarizing influences on climate attitudes.