• picture
  • picture
PRI's Environmental News Magazine

Emerging Science Note/Arctic Shrubs

Air Date: Week of September 9, 2005

stream/download this segment as an MP3 file

Living on Earth's Jennifer Chu reports on new shrub growth in the Arctic that may be part of a warming feedback loop.

Transcript

CURWOOD: Just ahead: saving all creatures great and small in the aftermath of Hurricane Katrina. First, this Note on Emerging Science from Jennifer Chu.

[SCIENCE NOTE THEME]

CHU: In the barren core of Arctic tundra, winter seems infinite, endless, as if it could – and would – last forever. And it almost does. Eight to ten months out of the year, it is winter in the treeless land at the top of the world. But cropping up amid the starkness and the snow are increasing numbers of shrubs – shrubs that could shift the tundra’s delicate energy balance and cause warming of several degrees over the next few decades.

A new study by the American Geophysical Union found that increasing vegetation reduces the earth’s albedo, or the reflection of the sun’s rays from the surface. While snow reflects solar energy, dark-colored shrubs absorb it. The study monitored terrain ranging from forested canopy to tundra, and found that melting began several weeks earlier in places where shrubs were exposed than in snow-covered areas.

Climate warming seems to stimulate shrub advancement. Scientists call it a feedback loop- increased shrub growth produces higher temperatures, and higher temperatures induce further growth. Scientists predict that if shrubs continue to grow on the tundra, winter heating could increase by up to 70 percent over a period of decades. And the continued transition from tundra to shrub land could substantially alter the character of the Arctic.

That’s this week’s Note on Emerging Science. I’m Jennifer Chu.

CURWOOD: And you're listening to Living on Earth.

 

 

Living on Earth wants to hear from you!

P.O. Box 990007
Prudential Station
Boston, MA, USA 02199
Telephone: 1-617-287-4121
E-mail: comments@loe.org

Donate to Living on Earth!
Living on Earth is an independent media program and relies entirely on contributions from listeners and institutions supporting public service. Please donate now to preserve an independent environmental voice.

Newsletter
Living on Earth offers a weekly delivery of the show's rundown to your mailbox. Sign up for our newsletter today!

Major funding for Living on Earth is provided by the National Science Foundation.

Committed to healthy food, healthy people, a healthy planet, and healthy business.

Innovating to make the world a better, more sustainable place to live.

Kendeda Fund, furthering the values that contribute to a healthy planet.

The Grantham Foundation for the Protection of the Environment: Committed to protecting and improving the health of the global environment.

Contribute to Living on Earth and receive, as our gift to you, an archival print of one of Mark Seth Lender's extraordinary hummingbird photographs. Follow the link to see Mark's current collection of photographs.