Max Boykoff has written a cool book (material from which played a major role in a panel session at the 2012 Ocean Sciences conference) examining media coverage of climate change in the U.S.
Who Speaks for the Climate? documents in a more rigorous and informative way than anything I've ever read the conservation of "balance" in the media coverage of the climate change debate no matter how lopsided the scientific evidence becomes.
Boykoff's own take -- and that of pretty much everyone I've heard comment on this phenomenon -- is negative: there is something wrong w/ norms of science journalism or the media generally if scientifically weak arguments are given just as much space & otherwise treated just as seriously as strong ones.
I have a slightly different view: "balanced" coverage is evidence of the expressive rationality of public opinion on climate change.
News media don't have complete freedom to cover whatever they want, however they want to. Newspapers and other news-reporting entities are commercial enterprises. To survive, they must cover the stories that people want to read about.
What people want to read are stories containing information relevant to their personal lives. Accordingly, one can expect newspapers to cover the aspect of the "climate change story" that is most consequential for the well-being of their individual readers.
The aspect of the climate change story that's most consequential for ordinary members of the public is that there's a bitter, persistent, culturally polarized debate over it. Knowing that has a much bigger impact on ordinary individuals than knowing what the science is.
Nothing an individual thinks about climate change will affect the level of risk that climate change poses for him or her. That individual's behavior as consumer, voter, public discussant, etc., is just too small to have any impact --either on how carbon emissions affect the environment or on what governments do in response.
However, the position an individual takes on climate change can have a huge impact on that' person's individual social standing within within his or her community. A university professor in New Haven CT or Cambridge Mass. will be derisively laughed at and then shunned if he or she starts marching around campus with a sign saying "climate change is a hoax!" Same goes for someone in a mirror image hierarchical-individualistic community (say, a tobacco farmer living somewhere in South Carolina's 4th congressional district) who insists to his friends & neighbors, "no, really, I've looked closely at the science -- the ice caps are melting because of what human beings are doing to the environment."
In other words, it's costless for ordinary individuals to take a positon that is at odds with climate science, but costly to take one that has a culturally hostile meaning within groups whose support (material, emotional & otherwise) they depend on.
Predictably, then, individuals tend to pay a lot of attention to whatever cues are out there that can help them identify what cultural meanings (if any) a disputed risk or related fact issue conveys, and to expend a lot of cognitive effort (much of it nonconscious) to form beliefs that avoid estranging them their communities.
Predictably, too, the media, being responsive to market forces, will devote a lot more time and effort to reporting information that is relevant to identifying the cultural meaning of climate change than to information relevant to determining the weight or the details of scientific evidence on this issue.
So my take on Boykoff's evidence is different from his.
But it is still negative.
It might be individually rational for people to fit their perceptions of climate change and other societal risks to the positions that predominate in their communities but it is nevertheless collectively irrational for them all to form their beliefs this way simultaneously: the more impelled culturally diverse individuals are to form group-congruent beliefs rather than truth-congruent ones, the less likely democratic institutions are to form policies that succeed in securing their common welfare.
The answer, however, isn't to try to change the norms of the media. They will inevitably cover the story that matters to us.
What we need to do, then, is change the story on climate change. We need to create new meanings for climate change that liberate science from the antagonistic ones that now make taking the "wrong" position (any position) tantamount to cultural treason.