News Release

Talking 'green' can help candidates win votes, Stanford study finds

Peer-Reviewed Publication

Stanford University

Political candidates get more votes by taking a “green” position on climate change – acknowledging that global warming is occurring, recognizing that human activities are at least partially to blame and advocating the need for action – according to a June 2011 study by researchers at Stanford University.

Among Democratic and Independent voters, a hypothetical United States Senate candidate gained votes by making a “green” statement on climate change and lost votes by making a “not-green” statement – expressing skepticism about global warming – compared to making no statement on climate, the study found. Among Republican voters, the hypothetical candidate neither gained nor lost votes by taking either position.

The results suggest that candidates of either party can gain the votes of Democrats and Independents without losing Republican votes, said lead author Jon Krosnick, professor of communication and of political science at Stanford, and senior fellow at the Woods Institute for the Environment.

“These results are powerful because they suggest what might be clear winning strategies for candidates running for office,” said Krosnick, who has been conducting national surveys of public opinion on climate change for more than a decade.

A policy issue like climate change does not typically influence the votes of all citizens, he explained. Instead, only people who pay close attention to the issue and consider it to be of extreme personal importance are likely to base their votes on it. Of the 38 million Americans who fall into that category, he said, the vast majority hold “green” views on global warming – they believe that the average global temperature has been increasing and that human activities are at least part of the cause, and they believe that government action is needed to mitigate the effects.

The new study was based on a nationwide telephone survey of a representative sample of American adults between Nov. 1 and Nov. 14, 2010 – around the time of the most recent national election – and statewide telephone surveys conducted in Florida, Maine and Massachusetts in July 2010.

Survey interviewers read different quotes about global warming from a hypothetical Senate candidate to survey respondents. “Some respondents heard the candidate say nothing about climate,” said Krosnick. “Other respondents heard the candidate take a green position on climate. And, in the national survey, some respondents heard the candidate take a not-green position on climate.”

All respondents also heard the candidate take positions on a series of issues other than climate change, he added.

Results: Who cares about climate?

According to the results of the nationwide survey, 77 percent of all respondents said they would vote for the hypothetical candidate who took a green position on climate change, while 65 percent supported the candidate who was silent on the topic. “Among respondents who heard the candidate take a not-green position on climate, only 48 percent said they would vote for him or her,” said Krosnick.

Krosnick also examined how people with different political party affiliations responded to the candidates’ statements on climate change.

The majority of Democrats and Independents said they would vote for the hypothetical candidate with a “green” stance on climate – 74 percent and 79 percent respectively. By comparison, a candidate who said nothing about climate received support from 53 percent of Democrats and 63 percent of Independents. Only 37 percent of Democrats and 44 percent of Independents said they would vote for the candidate whose quotes conveyed disbelief in global warming – a statistically significant decline for both groups of voters.

In contrast, the hypothetical candidate’s views on global warming had no significant impact on Republican survey respondents, according to Krosnick, with 83 percent of Republicans saying they would vote for the candidate who was silent on climate, 78 percent for the “green” candidate and 76 percent for the “not-green” candidate.

The researchers found similar results in the three statewide surveys conducted in Florida, Maine and Massachusetts in July 2010.

Green gains

“The results suggest that by taking a green position on climate, candidates of either party can gain the votes of many citizens,” said Krosnick.

Assuming that Independent voters play an especially important role in determining the outcomes of elections, “our results suggest that candidates would do best to take green positions on climate change and would hurt their electoral chances by taking not-green positions,” he added.

Republican candidates might have even more to gain than do Democratic candidates by acknowledging global warming, he said. “In addition to helping to attract Independent voters, Republican candidates who take green positions may have some success wooing Democratic citizens in general elections, especially if their Democratic opponents remain silent on climate,” said Krosnick. “Taking a green position on climate will apparently not hurt a Republican candidate’s standing with Republican voters, so this seems like a cost-free strategy.”

Krosnick noted that the new study does have certain limitations, because a brief survey can’t include all of the issues and world events that candidates address during their political campaigns. Other factors could influence voters in an actual election as voters learn about the background and experiences of candidates, he explained.

The study results don’t necessarily represent the views of people who actually influence election decisions, either, he said. That’s because even though all of the people surveyed were adult Americans, not all of them would vote in an election. And although interviewers asked respondents about their intentions to vote, they didn’t observe how people actually cast ballots in a real election. (However, other studies have confirmed that people’s stated voting intentions are usually consistent with how they end up voting, Krosnick noted.)

“Perhaps most important, we did not examine what would happen in voters’ minds if a candidate took a green or not-green position and was then attacked by his or her opponent for doing so, which could certainly be studied in future experiments,” he said.


The other co-authors of the study are Bo MacInnis and Ana Villar, researchers in Stanford’s Department of Communication and Institute for Research in the Social Sciences.

This research was supported by the National Science Foundation and by the Woods Institute for the Environment.

This article was written by Sascha Zubryd, a science-writing intern at the Woods Institute for the Environment at Stanford University.

Relevant URL:

Woods Institute for the Environment

COMMENT: Jon Krosnick, Woods Institute for the Environment: (650) 725-3031,

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