Though a majority of Americans believe in global warming, Bill Moyers said -- 74% percent, according to a new study by Yale University and George Mason University -- the topic has been curiously absent from the U.S. presidential elections.

But on this week's Moyers & Company, he discussed some of the long-term effects of the phenomenon with photographer turned documentarian James Balog, who documents the disappearance of the Earth's glaciers in both a new book and film.

Using specially-designed cameras, Balog tracked what he called "glacial retreat," including one glacier that had dropped 11 miles since 1984.

"It's like air being let out of a balloon," Balog said. "You can see what's called the trim line; it's the high water-mark of the glacier in 1984. That vertical change is the height of the Empire State Building."

Though the planet has always gone through cycles of glaciers ebbing and flowing, Balog said, environmental changes over the past four decades have led to a level of carbon dioxide concentration in the atmosphere unseen in tens of millions of years.

"So people say, you know, why do we care about this warming that’s happened before? Well, guess what? People didn't live here when it was like that," Balog told Moyers. "The age of agriculture, the age of industrial civilization depends on us living within this relatively comfortable range of temperature and precipitation and atmosphere that we've been in for the past 10,000 years. We're pushing ourselves far outside our range of comfort right now. And that's the real danger."

Moyer's discussion with Balog, published Friday, can be seen below.

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