分享：What Drives Public Opinion About Climate Change?（CJR）

竹林中人

The media influence public opinion about climate change, but not as much as national politicians and the state of the economy do, according to a new analysis of eight years of polling data.
Over time, activists have pointed their fingers in many directions while trying to explain society’s failure to address the threat of climate change. Scientists, policymakers, captains of industry, advocates, and the weather have all been blamed for the nation’s general indifference to the matter, but journalists seem to shoulder a particularly large share of blame.
Take a recent a statement by James Hansen, the director of NASA’s Goddard Institute for Space Studies and one of the country’s preeminent climatologists, who has become a vocal campaigner for reducing heat-trapping greenhouse gas emissions.
“Public doubt about the science is not an accident,” he wrote in a personal letter posted online at the end of January. “People profiting from business-as-usual fossil use are waging a campaign to discredit the science” by manipulating the news:

Today most media, even publicly-supported media, are pressured to balance every climate story with opinions of contrarians, climate change deniers, as if they had equal scientific credibility. Media are dependent on advertising revenue of the fossil fuel industry, and in some cases are owned by people with an interest in continuing business as usual.

Such comments typify the slapdash scapegoating of journalists that is so popular these days. Though the dilemmas Hansen cites are important, “false balance” is not the problem it used be. And while I haven’t seen a breakdown of the media’s latest revenue streams, I’d guess that news outlets are also less financially dependent on the fossil fuels industry than they used to be. That’s no excuse for the poor reporting and conflicts of interest that do exist, but focusing on these flaws to explain the lack of action on climate change distracts attention from more important factors.
That’s the suggestion, at least, of an analysis of public-opinion trends published in the journal Climatic Change on February 3. Using the results of 74 public-opinion surveys conducted between January 2002 and December 2010—which asked a total of 84,086 people 14 questions about their perception of climate change—researchers created a “Climate Change Threat Index” that allowed them to map the swings in public opinion over the course of eight years.
Following stable, tepid concern from 2002 to 2005, apprehension began to climb in 2006, peaked in late 2007, and then fell back to where it was in 2002. But the team of three sociologists, led by Drexel University’s Robert Brulle, wanted to know why, so they gathered data on five likely influences: extreme weather events, scientific information, media coverage, congressional attention, and advocacy groups on both sides of issue. They also looked at four control variables: unemployment, gross domestic product, war deaths in Iraq and Afghanistan, and the price of oil. The team then compared that data to changes in the Climate Change Threat Index.
They found the most important factors that influenced public concern were public statements by Democrats in support of addressing climate change; anti-environmental votes by Republicans; unemployment; GDP; and the number of times The New York Times mentioned the film, An Inconvenient Truth.
Media coverage was an important, third-order influence on people’s perception, but like public opinion itself, it too was “largely a function of elite cues and economic factors,” according to the analysis. The researchers gauged media coverage measured by the number of stories about climate change on the three major broadcast TV networks and in The New York Times, Newsweek, Time, and US News & World Report. Other, minor influences also reflected some media activity, however. For instance, in addition to peer-reviewed papers published in the journal Science, the “scientific information” category included climate change coverage in 15 popular science magazines. And the “advocacy” category included climate change coverage in 12 major environmental magazines and six conservative magazines.
The importance of the media should not be minimized. The study found that “the greater the quantity of media coverage of climate change, the greater the level of public concern,” and that “the importance the media assigns to coverage of climate change translates into the importance the public attaches to this issue.” (In other words, front-page treatment means readers will take an article more seriously.) But, the researchers, wrote:

The implication would seem to be that a mass communication effort to alter the salience of the climate change issue is unlikely to have much impact. A great deal of focus has been devoted to the analysis and development of various communications techniques to better convey and understanding of climate change to individual members of the public. However, this analysis shows that these efforts have a minor influence, and are dwarfed by the effect of the divide on environmental issues in the political elite. Additionally, the analysis has show that, in line with the media effects literature, the effects of communication on public opinion regarding climate change are short lived. A high level of pubic concern over climate change was seen only during a period of both high levels of media coverage and active statements about the issue’s seriousness from political elites. It rapidly declined when these factors declined.

Stanford University’s Jon Krosnick, an expert in public-opinion polling who wasn’t involved in the analysis, told ClimateProgress that there are inherent uncertainties in the study, but he praised its overall methodology.
The authors acknowledged that they could track only the long-term, rather than short-lived factors that affect public opinion. They also cited the need to study a wider variety of variables, such the public demonstrations and advertising by advocacy groups and climate coverage of cable TV networks, talk radio, and comedy programs like The Daily Show. The molding of pubic opinion will always be an immensely complex process that defies simple explanations.
Nonetheless, the study is a valuable contribution to an often vitriolic debate about who is responsible for the general apathy surrounding climate change. Activists, scientists, politicians, and other stakeholders are often quick to point fingers at journalists and the wider media, who are not blameless, to be sure. But those accusations tend to be shortsighted and distract attention from potentially more important factors.