(Political) party animals

Americans are real party animals — at least when it comes to interpreting global warming. That’s the conclusion of a new report in the September/October Environment. In it, university scientists use Gallup poll data to show that Democrats and Republicans have exhibited increasingly consistent but divergent beliefs over the past decade about the certainty of climate change.

During this period, climatologists, environmental scientists and geologists have largely reached a consensus that the planet is warming and that human activities must carry much of the blame. While Democrats have generally grown to accept that assessment, increasing numbers of Republicans have done the opposite.

Polling data are notoriously suspect. The answers people give are often heavily influenced by the precise wording of a question. And sometimes people offer up answers that they think the questioner wishes to hear — or vice versa. That said, if the authors’ assessment of the polling data in this paper turn out to be true, we’re in trouble. Because they suggest that a large share of Americans make science take a back seat to partisan rhetoric and/or boosterism.

In 1997, some 27 percent of Democrats and 37 percent of Republicans thought news of global warming was exaggerated. As of March of this year, only 17 percent of Democrats still held that view, while a whopping 59 percent of Republicans did.

When respondents were asked whether most scientists believe global warming has been empirically established, only 52 percent of polled Democrats said yes in 1997 compared to 75 percent of them today. A smaller increase was observed among Republicans over that period — from 42 percent a decade ago to 54 percent now.

As for the human role in climate change: Democrats have held steady — at around 70 percent — in their belief that a considerable share of global warming is due to human activities such as burning fossil fuels. Over the same decade, Republicans’ belief that humans must take much of the blame for warming has fallen — from 53 percent in 1997 to 40 percent this past March.

Gallup pollsters also have asked groups of politically affiliated people about whether they feel global warming poses a serious threat to the American way of life. Over the past decade, Dems have increasingly said yes — from 31 percent initially, to 49 percent now. Republicans have also increasingly said yes, though the overall share has been much smaller: 20 percent initially, compared to 26 percent now.

In other words, while virtually half of Democrats currently view global warming as posing a serious threat within their lifetimes, only one-quarter of Republicans feel similarly, report Oklahoma State University sociologist Riley E. Dunlap (who’s also a Scholar for the Environment at the Gallup Organization) and sociologist Aaron M. McCright of Lyman Briggs College and Michigan State University.

The pair argue that the polling data suggest Republicans and Democrats are becoming “more ideologically polarized,” at least on the issue of global warming. They attribute the increasingly divergent views on this issue to “party sorting” — that is, people choosing a party on the basis of its general views on this issue, or people within a party increasingly assuming the views on this issue that are espoused by leaders of their party.

Dunlap and McCright find that the tight correlation between party affiliation and attitudes about climate hold even after accounting statistically for other potentially confounding demographic factors such as gender, age, race, income and education. Moreover, they observe, throughout the past decade, “Republicans and Democrats who believe they understand global warming reasonably well [have been holding] more divergent views compared with their presumably less-informed counterparts.”

The bottom line: Democrats’ views have tended to reflect the scientific assessments on climate change at the same time that Republicans have tended to dismiss the scientific assessments.

This doesn’t bode well for the possibility that Republicans in Congress, the Statehouse or even the White House would base future environmental policies on sound science. At least not if they decide that science is discretionary — something to embrace only if it jibes with some preexisting objectives.

Both Senators John McCain and Barack Obama have argued that they believe the planet is warming, that human activities have played a large role in this, and that our way of life is in peril if we don’t quickly move away from deriving most of our energy from the burning of fossil fuels.

In fact, it’s because McCain’s views on global warming deviate from the Republican norm that Dunlap and McCright suspect a McCain victory in November may offer the best chance of winning over climate-change skeptics.

If Obama wins and cites science as the basis for new and costly climate-protection policies, Republicans might dig in their heels and fight them. But if McCain wins, Dunlap and McCright argue, he might sway others in his party to embrace global-change data and action.

It’s an interesting hypothesis. And there’s only one way to test it .…

Janet Raloff is the Editor, Digital of Science News Explores, a daily online magazine for middle school students. She started at Science News in 1977 as the environment and policy writer, specializing in toxicology. To her never-ending surprise, her daughter became a toxicologist.

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