Two-thirds of all Americans are confident that climate change is real, and well-supported by evidence, according to a new National Survey on Energy and Environment (NSEE), a twice-yearly study from the University of Michigan and Muhlenberg College in Pennsylvania. Meanwhile, the number of respondents who say there is no solid evidence of global warming is at a record low: just 15 percent, versus 24 percent one year ago.

The NSEE has been measuring public opinion on climate change since 2008, when 72 percent of respondents said global warming was a reality. But with the early months of 2016 marking some of the hottest in human memory, and election season now in full swing, the results of this year's survey may be especially telling.

A majority of Americans believe that there is evidence that climate change is occurring, but the question remains a deeply polarizing one: conviction in their own viewpoint has also increased, among both believers and skeptics.

“This study certainly represents a shift in thought,” one of the study’s authors, Sarah Mills, a postdoctoral researcher at the University of Michigan’s Gerald R. Ford School of Public Policy, tells The Christian Science Monitor. “More than ever in the past, the science is not necessarily up for debate.”

Just 15 percent of Americans believe that there is no doubt that climate change is occurring, according to the study, while 66 percent of Americans believe that there is solid evidence for world climate change. Both of these numbers are down from last fall’s survey, which showed that 70 percent of Americans saw that there was solid evidence for climate change, while 16 percent believed that there was not solid evidence.

As recently as two years ago, in 2014, a third of the country had serious doubts as to whether or not there was evidence for global warming, meaning that this spring’s rate of 15 percent is a more than 50 percent reduction over a short period of time.

Yet there is still a steep partisan divide between climate change believers and skeptics, a difference thrown into sharper relief during the presidential election, says Dr. Mills.

Last fall, the NSEE found that among Republicans surveyed, 26 percent had doubts about the evidence for climate change. This spring, that number jumped to 34 percent. The number of those unsure whether or not evidence supports climate change also rose, from 18 to 26 percent.

Donald Trump's history of calling climate change a "hoax" and sudden rise to political prominence may have affected Republican views on the issue, Mills believes.

"This change in belief is one of the most dramatic shifts we have seen in the six month period between the fall and spring surveys," she tells the Monitor.

David Konisky, an associate professor at the University of Indiana, Bloomington's School of Public and Environmental Affairs, cautions that other factors have also shaped the sudden rise in GOP skepticism.

"I don't think we can ascribe any changes in public opinion to Donald Trump alone," Dr. Konisky tells the Monitor. "People are paying more attention to politics and to where the Republican party stands."

Among both camps, convictions have grown stronger. A record 71 percent of those who believe climate change is occurring say they are "very confident" about their view, while another 24 percent say they are "fairly confident." Among doubters, 55 percent are "very confident" it is not occurring – also an all-time high – while 29 percent are "fairly confident."

Belief in climate change normally drops slightly after the winter has ended, Mills says, but unseasonably warm temperatures this winter seem to have mitigated that effect. It's a trend she expects will continue, although she is curious to see how Republican views will change as the election continues.

"Given how hot the year has been, I would expect belief in climate change to increase in the fall," she adds.

Nationwide, the number of Americans who believe there is "no solid evidence" of climate change has reached its lowest point since the NSEE was first conducted in 2008: just 15 percent. Those who are becoming more entrenched in that view aren't necessarily sticking their heads in the sand, says Mills, but often point to events in their own lives to back up their position: strong winter storms, for example.

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The survey does leave out one crucial question, Konisky says: How many climate change believers are convinced that the process is caused by humans? And – perhaps more importantly, he says – how many respondents are actually concerned about climate change?

"There's a difference between people expressing support for something, and the salience of the issue," he tells the Monitor. "Until climate change becomes an issue of great importance for people, I don't think that we're likely to see a change in public policy."