This photo from NASA's Suomi NPP satellite shows the Eastern Hemisphere of Earth in "Blue Marble" view. The photo, released Feb. 2, 2012, is a companion to a NASA image showing the Western Hemisphere in the same stunning detail. This photo was taken on Jan. 23.

A prominent physicist has publicly announced that he is no longer a climate-change skeptic, but broader public sentiment may be becoming more, rather than less, entrenched.

Recent research has found that an increased number of Americans have a knee-jerk reaction to global warming, believing it to be a hoax or conspiracy. And climate change has entered the realm of politics, said Anthony Leiserowitz, the director of the Yale Project on Climate Change Communication. There, it's become subject to the same polarizing forces that are pushing Republicans and Democrats apart more generally.

"It's the trend that I find in some ways the most disturbing, because in the end, the climate system doesn't care whether you're a Democrat or a Republican," Leiserowitz told LiveScience. "It's not like the floods are only going to hit Democrats and not Republicans or that the droughts are going to impact liberal farmers and not conservative ones. In the end, we all will suffer together and in the end, we'll all have to solve this together."

Skeptic's change of heart

The latest volley in the public-relations battle over climate change was launched by University of California, Berkeley physicist Richard Muller. Muller was skeptical of the broad agreement among climate scientists that the globe is warming and that humans are the primary cause. He and his colleagues, funded in part by the libertarian Charles Koch foundation, which has traditionally backed groups that seek to deny climate change, began a massive independent assessment of more than 200 years of land-temperature reports to try to confirm or deny warming. The results revealed an increase in global average land temperature of 2.5 degrees Fahrenheit (1.4 degrees Celsius) over the past 260 years, an increase that followed closely with the increase in carbon dioxide emissions, consistent with earlier findings by other climate researchers. [The Reality of Climate Change: 10 Myths Busted]

On July 28, Muller wrote a New York Times op-ed piece stating that his results had not only convinced him that climate change is happening, they also strongly suggested that "humans are almost entirely the cause."

The reactions to Muller's findings, now playing out on climate blogs Internet-wide, are way too "inside baseball" to widely affect public opinion on climate change, Leiserowitz said.

"It is completely gone out of most people's heads already of the limited amount of Americans that even saw any of this, so will it change public opinion? Not at all," he said.

On the other hand, such a prominent turnaround does convey an important message about science, said Ed Maibach, the director of the Center for Climate Change Communication at George Mason University.

"If the evidence is clear, [scientists] will change their minds," Maibach said. "That's exactly what's happening here, though whether or not it ends up changing minds of people in the public remains to be seen."

The politicization of climate change

Part of the problem is that climate change has moved out of the realm of research and into the political arena, Leiserowitz said. The climate-change views of the two political parties were not significantly different until the Kyoto Protocol negotiations of 1997, when policymakers began to look for solutions to global warming.

This was in the midst of the polarizing Clinton administration, and for some, the association made global warming belief seem unsavory. Even today, many climate-change naysayers think of former vice president Al Gore when they hear the words "climate change."

"They loathe Al Gore," Leiserowitz said. "Sometimes I joke that Al Gore could hold a press conference tomorrow to say that science has determined that the Earth is round and people out there would say, 'Well, no it isn't.'" [50 Cool Facts About Earth]

The findings about Gore come from a recent paper published by Leiserowitz and his colleagues in the journal Risk Analysis. In large public surveys, the researchers asked Americans to give their first thoughts when hearing the words "global warming." In 2003, just 7 percent of Americans responded with "naysayer" answers, such as "hoax" or "scam." By 2010, that number had risen to 23 percent. (Studies show that the majority of Americans do believe in global warming, Maibach said, but there is also a widespread misconception that there is disagreement among scientists over whether it is happening.)

The Earth truly is a planet of extremes, from ice-cold tundra to steamy rain forests, from ocean trenches to snow-covered peaks.

Earth Quiz: Mysteries of the Blue Marble

The trend is driven by a few factors, Leiserowitz said. Political polarization is one. Like being anti-abortion or in favor of strict immigration laws, denial of climate change has become a "litmus test" for the Republican Party, he said. The "Climategate" scandal, in which emails between climate researchers were hacked from a University of East Anglia server in the United Kingdom, also diminished trust in climate scientists. Those emails were taken by some to suggest climatologists were making false statements about global warming. Climategate was covered more often in conservative media, Leiserowitz said. Though the scientists involved were eventually cleared of wrongdoing, the stigma stuck.

Finally, President Barack Obama's stated concern about climate change turns off people who don't like the president for his other policy stances, Leiserowitz said.

"If you don't trust the messenger, you're going to discount or reject the message," he said.

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