U.S. belief that global warming is occurring weighed over all polls since 1986 to 2012. How you ask the question skews the results when it comes to public opinion on global warming, finds an analysis of hundreds of polls by The Strategy Team. The public mostly agrees on global warming's reality, it says. Graphic: The Strategy Team

By Dan Vergano
23 March 2013 (USA TODAY) – How you ask the question skews the results when it comes to public opinion on global warming, finds an analysis of hundreds of polls. The public mostly agrees on global warming’s reality, it says. The Arctic keeps melting, the atmosphere keeps warming, and polls keep bouncing around on what people think about global warming. After every hurricane, heat wave, or hullabaloo over climate science, the polling results come, watched breathlessly for some shift in U.S. public opinion about global warming. All the hand-wringing may not have amounted to anything, suggests one long-term look at all those polls. The majority of the public pretty much understands that global warming is happening, and has for a long time, the authors say. Some of what looks like confusion about what folks think may result more from the poll questions themselves, rather than from the people answering the questions. “Belief that global warming is happening has been mostly stable and increasing for the last thirty years,” says social scientist Orie Kristel of The Strategy Team, an applied social science company based in Columbus, Ohio. The agreement has approached 75%, and although it dipped in recent years, that consensus has since resumed its upward march, according to a just-released report sponsored by the Skoll Global Threats Fund, a foundation founded by eBay billionaire Jeff Skoll that looks for solutions to global problems such as pandemics, nuclear proliferation, and environmental challenges. In it, Kristel and his colleagues weigh together public opinion polls dating back to 1986, from more than 150 nationwide questionnaires in all. He and his colleagues report that wording of poll questions may have created some of the appearance of shifts in public opinion about global warming. “Do you think the greenhouse effect really exists or not?” a poll first asked U.S. respondents in 1986. About 73% answered “yes” in that year, setting a pattern. When pollsters asked folks whether they believed climate change was happening in some sense, most said they did. When they asked folks, “Is there solid evidence the average temperature on Earth has been getting warmer over the past four decades, or not,” as a Brookings Institution survey asked in 2007, the responses were “consistently lower,” the analysis finds. More polls have been asking the question this way in recent years. In other words, ask people what they believe and they will mostly say they believe global warming is happening. If you pile on top of that question the additional task of asking people to assess what they know of the evidence (which may be very little), they become more doubtful in their answers. In that case, more than half of people say they believe in global warming, but the level of agreement drops below 70%, Kristel says. [more]

Poll questions shift public views on global warming