Clark Planetarium director Seth Jarvis reads a great deal of scientific literature as part of his job. Scientific research, he said, presents evidence that is, "dare I say, overwhelming," that global warming is taking place — and he thinks humans are causing it.

Don Colton, an amateur astronomer who also closely follows scientific studies, has a different view.

Global warming is taking place, but humans are not to blame, he said. Warming is part of a cycle of climate variations that Earth has been going through for hundreds of thousands of years, Colton added.

Where do Utahns in general stand on this important issue?

Perhaps surprisingly for a politically conservative state, they side with Jarvis, according to a new Deseret Morning News/KSL-TV poll.

The results were tallied by Dan Jones & Associates, who interviewed 410 Utahns throughout the state. The poll, conducted June 26-28, has a 5 percent margin of error.

Asked if they believe that Earth's weather is growing hotter — "in other words, do you believe in global warming?" — positive responses came from more than two-thirds, at 69 percent. Those who disagreed were 25 percent, with others saying they don't know.

Of those who believe in global warming, 84 percent thought humans are causing or increasing it.

Democrats were much more likely to believe in the phenomenon than those of other political affiliations: Among Democrats, 87 percent think global warming is taking place; among Republicans, 56 percent; independent voters, 76 percent; other political groups, 74 percent.

"There is a consensus" among scientists, Jarvis said in a telephone interview. "The consensus is growing clearer by the day that climate change is happening, that it is significant, and happening faster than we previously experienced."

He said the "overwhelming likelihood is, it is human-caused."

Colton said changes in solar activity might play a role in the present warming trend.

"What we're seeing is just a cyclical thing," he added.

Colton said trails, way stations and artifacts, all from the Medieval period, have been emerging from the snow in the Alps.

The Alpine region is growing warmer, but the ancient paths are not yet fully open. The implication is that Earth was warmer back when the trails were made, according to Colton.

A strong majority of Utahns, however, don't believe today's global warming is strictly a natural process. They think global warming is real and that it is caused or increased by humans, according to the new poll.

Yet they don't think it's a significant problem.