A new film that took Northern Arizona University researchers from Colorado to Alaska to Switzerland to study past climates will make its local television debut later this month.

Taking Earth’s Temperature: Delving into Climate’s Past, produced by NAU’s IDEA Lab, is scheduled to air at 6 p.m. Saturday, Sept. 20, on Phoenix’s KAET (Channel 8).

The one-hour documentary follows NAU Regents’ professor Darrell Kaufman and his research team as they explore records of past climate changes found in lake sediment from arctic lakes. It also shows how scientists from around the world have collaborated to paint a new and detailed picture of the last two millennia of the Earth’s temperature history using evidence from coral reefs, caves, tree rings, glaciers and more.

“Climate changes of the past provide us with tremendous scientific value,” Kaufman said. “Think of a planet where climate is decoupled from fossil-fuel consumption. We’d still want to know what lies ahead: How the next uptick in solar energy will impact the rate of ice-sheet melting, or how the next major volcanic eruption will influence monsoons in the Southwest.”

By looking at how the Earth’s climate has changed over time and comparing records from different parts of the world, scientists have been able to come to a much more intricate understanding of why those patterns fluctuate, to recognize variations that are not natural and to test and improve predictive climate models. If those models can accurately explain past changes, then they may also provide a look at what will happen to Earth’s climate in the future.

“Climate is always changing, and it always will,” Kaufman said. “To understand these longer-term fluctuations requires a perspective that transcends the space and time of most daily human experience. It requires a long-term and global view of climate.”

NAU researchers Deborah Huntzinger, Nicholas McKay, Scott Anderson and David Fortin also appear in the film. Filmmakers from the IDEA Lab include Dan Boone, Ryan Belnap and Peter Friederici.

For a full schedule of show times on PBS stations across the country, visit http://www.takingearthstemperature.org/showtimes.