2006年VOA标准英语-Alaska Feeling Impact of Global Warming（在线收听）

By Brian Padden
Anchorage, Alaska
09 August 2006
 
watch Alaska Global Warming

Global warming is considered a cause of glaciers melting   
  
While there is still an ongoing debate about the extent and impact of global warming worldwide, many scientists believe global warming is having profound effects in the arctic and sub-arctic regions.  Glaciers are said to be melting at an unprecedented rate.  Species of flora and fauna -- which thrive in the cold -- are now being threatened. 

-------

 
Biologist Jeff Welker 
  
Biologist Jeff Welker with the University of Alaska in Anchorage says the melting of Porter Glacier in the last 20 years illustrates how global warming is dramatically changing the sub-arctic climate here in the U.S. state of Alaska.   

"There are a few bits of the Portage glacier that are here in front of us. This is the kind of proximity that the glacier front was to the visitor center that was built here 15 to 20 years ago.  Today now all we have are these small little remnants that we see directly here in front of the glacier.  While the glacier itself is over a mile, a mile and a half away now."   

Stream ecologist Sue Mauger   
  
Stream ecologist Sue Mauger has been documenting a less dramatic, but unprecedented rise in water temperature in Alaska's rivers and streams.   "We are finding that the water temperatures are increasing and that the numbers of days they're exceeding, the water temperature is increasing, the numbers of hours per day they're increasing, and the maximum temperatures are increasing."

Ecologist Ed Berg with the U.S. Fish and Wildlife Service in Alaska digs below the earth's surface to put this period of global warming into historical context.

Ecologist Ed Berg  
  
"When I dated one of the spots where I augured I got a radiocarbon date of 13,000 years. In the last few decades, this bog has dried out and the shrubs and trees are moving in big time.  That a very typical example of the drying landscape in this area and, as I say, it is a profound change from 13,000 years of being a pretty wet place." 

These scientists are not just documenting that the Earth is warmer than is has ever been in recorded history.  They are also warning that the impact of global warming -- being felt first and foremost in the fragile arctic and sub-artic eco-systems -- could dramatically change life on Earth. 

Ed Berg says, while beetles are responsible ravaging much of the spruce forests in Alaska and Canada, the real culprit is global warming. "In 1987 we went into overdrive essentially and had an 11-year run of warm summers and that we think is unprecedented in the last 250 years.  It allowed the beetles to grow and grow and essentially eat themselves out of house and home."

Ecologist Sue Mauger says that if temperatures continue to rise, Alaskan salmon will be threatened by parasites that thrive in warmer climates. "The predictions are that our air temperatures here in sub-arctic Alaska will increase as much as three to five degrees centigrade.  And if the water temperatures increase that same amount, we are going to be seeing a much less healthy fish population."

  
  
As Alaska changes into a warmer environment, some species will adapt and some, like the polar bear, could face extinction.  But that's not all.  Professor Welker says increased temperatures also mean increased energy in the atmosphere, which is causing more extreme weather events worldwide.  "Climate change increases the rate of unusual events.   We have very hard evidence now that the warming of the oceans across the globe is resulting in increased energy in the ocean to create a hurricane." 

He says while Alaska is not responsible for creating hurricanes, it is indicative of the consequences of warmer terrestrial habitats and warmer ocean systems.

-----

Note: It should also be noted that not all scientists agree that global warming is connected to extreme weather or that rising temperatures will have catastrophic effects.  They dispute the rate of rising temperatures and sea levels and say the scientific community should refrain from making premature and alarmist predictions. See our other reports in this series.