NOVA Online | Fire Wars | Woodland Lab Transcript

NOVA News Minutes
Woodland Lab
(running time 01:33)

Transcript
May 17, 2002

NARRATOR: We've been told that we must cut back on greenhouse gases or there will be global warming. But, as Steve Mirsky reports in this week's NOVA News Minute, scientists turned part of one forest into a Woodland lab to learn more about natural sources of greenhouse gases.

What's this forest fire have to do with this factory, or this traffic jam? They all produce greenhouse gases. While some scientists are studying ways to reduce industrial greenhouse gases, others are measuring nature's contribution.

NEIL SAMPSON (National Wildfire Consultant): I estimated that in the year 2000 with the fires that were in the 11western states that we may have released the equivalent of 75 million tons of carbon into the atmosphere through the carbon dioxide, carbon monoxide, and methane that was released."

NARRATOR: As shown on PBS's NOVA, scientists set an experimental fire in this forest in Alaska. Burning the forest will release gases from the trees and from the frozen soil beneath them. And fires do burn here regularly. They burned 900 acres of land, and then measured what burned.

BOB VIHNANEK (U.S.D.A. Forest Service Research): We have pins in the ground, which you can see one sticking up right here. Those were placed flush with the forest floor material before the burn, and so was—is exposed in the area that's burned.

NARRATOR: They estimate the fire produced 24,000 tons of greenhouse gases. That's like burning 2.4 million gallons of gasoline. Other scientists are now watching how the fire changed water flow in the forest, and how the forest grows in again and traps greenhouse gases. They're long-term questions to be answered in this "woodland lab." I'm Steve Mirsky.

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