Yale researchers have found that Americans are growing increasingly alarmed about climate change.

On March 15 Anthony Leiserowitz, director of the Yale Project on Climate Change Communication, appeared on national television saying that Americans are ready for the government to “end the silence” on climate change. He cited a study called “Global Warming’s Six Americas,” published on March 6 by researchers from the YPCC and the George Mason Center for Climate Change Communication, which showed that the number of Americans alarmed about climate change has increased from 10 percent in 2010 to 16 percent in 2012. Researchers from Yale and George Mason are now questioning whether public alarm about climate change is connected to weather extremities such as February’s 38-inch blizzard.

“There is something fundamentally different in the way Americans are engaging with the issue of climate change at this moment,” Leiserowitz said. “Our political leaders have been silent about the issue and the media has been very quiet. Now we are beginning to talk about it again.”

Researchers divided the U.S. population into six categories — alarmed, concerned, cautious, disengaged, doubtful and dismissive — based on their attitudes toward climate change. As of September 2012, the largest audience segment is the concerned group, the 29 percent of Americans who are “moderately certain” climate change is occurring and is human-caused. The smallest audience segment is the dismissive group, the 8 percent of Americans who are certain global warming is not occurring. Between 2010 and 2012, the number of Americans alarmed about global warming increased by 6 percentage points while the number of dismissive Americans decreased by 8 percentage points.

“We first identified the ‘six Americas’ in 2008 and have been tracking the evolution of their climate change beliefs, feelings, policy preferences and actions ever since,” said Edward Maibach, director of the George Mason Center for Climate Change Communication and a principal investigator of the study.

Maibach said he is currently working with Yale researchers to conduct a national survey examining how Hurricane Sandy and other recent weather events impacted American beliefs about climate change. Weather extremities have helped Americans understand that climate change has a dramatic impact on local communities and not only foreign nations, Leiserowitz said.

“[A] pervasive sense up to now has been that climate change is distant — distant in time and distant in space,” Leiserowitz said during his March 15 appearance on “Bill Moyers Journal.” “And what we’re now beginning to see is that it’s not so distant.”

Michael Mann, a climatologist who directs the Earth System Science Center at Pennsylvania State University, said that while scientists cannot conclusively prove that any single weather event in 2012 was caused by global warming, he believes the succession of climate extremities in the past year have elicited public alarm. He added that while there is no scientific consensus on whether global warming is causing more intense storms, there are “suggestive connections.”

“There is reason to believe that storms like Nemo might become more intense on average as the atmosphere warms, because of the clash of increasingly warm, moist air from the south with cold air outbreaks from the north,” Mann said in a Wednesday email.

Researchers interviewed 1,061 adults for their survey on “Global Warming’s Six Americas.”