Arctic Science Journeys
Radio Script
1997

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Longer Arctic Summers Not All Sunshine
for the Environment
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STORY: In your rush to get the garden planted and pack for summer vacations, you may not have noticed that spring came a bit earlier to the Arctic this year. Spring has been coming to the northern latitudes earlier and earlier since about 1981. Ranga Myneni is a scientist at Boston University.

MYNENI: "What we found was that north of 45 degrees north, the greenness has increased by approximately ten percent over a 10-year period. The second thing is that the springtime greening-up is happening about 8 days earlier in 1991 compared to 1982 or 1981."

Myneni examined satellite measurements of springtime plant growth north of the US-Canada border. He says the earlier spring is the result of a warmer Arctic climate that has reduced the amount of snow cover.

MYNENI: "Springtime snow cover extent had decreased in the high latitudes. So when you take away the reflective snow, there is more solar radiation absorbed at the surface and that contributes to near-surface warming. This warming is what has contributed to an earlier springtime greenup. Alaska, incidentally, is one area where we see substantial warming and greening."

Glenn Juday is a ecologist at the University of Alaska Fairbanks. He's examined tree rings as part of a long-term study of how the Arctic is responding to a warmer climate. Juday says a warmer climate should make the trees grow more. But just the opposite seems to be happening in the vast forested Interior region of Alaska. He says the problem is a lack of water.

JUDAY: "It's not a little thing. It's the thing that is holding back the trees right now. Even if we just keep the same amount of precipitation, it's bad because a warmer climate sucks more water out of the ground and out of the plants. If they don't have more moisture to make up for that, they're in deep weeds."

Juday says a prolonged warming of the Arctic will have a host of negative effects. Infestations of tree-killing insects like the spruce bark beetle that have already ravaged thousands of acres of forests in Alaska and Canada will become more common. Forest fires also will become larger and more frequent.

JUDAY: "That's kind of the short-term. I don't know if the climate is going to keep warming or not, but if it doesn't stop the trend that it's on, it's not going to be too far down the road that we'll see the forests beginning to thin out and the grasslands beginning to expand here in the Interior."

Scientists can't say for sure what's causing the Arctic climate to warm. But they say the likely cause is too much carbon dioxide gas in the atmosphere. Co2 gas given off by cars and factories through the burning of fossil fuels traps heat near the Earth.

Juday is among dozens of scientists who attended a four-day workshop in Fairbanks recently to talk about how global climate warming is affecting the Arctic's environment. The workshop is sponsored by the National Science Foundation, the University of Alaska Fairbanks Center for Global Change and the U.S. Department of the Interior.

OUTRO: For Arctic Science Journeys, this is Debra Damron reporting from Fairbanks, Alaska.