VOICE ONE: This is SCIENCE IN THE NEWS in VOA Special English. I'm Doug Johnson. VOICE TWO: And I'm Faith Lapidus. This week, we will tell about ice loss in the Arctic Sea.
(MUSIC) VOICE ONE: American scientists say ice covering the Arctic Sea continued to shrink last winter. The scientists say they recently found that older, thicker sea ice was increasingly replaced with new ice. The new ice is thinner and melts faster than the older ice.
The scientists work for the American space agency and the National Snow and Ice Data Center in Boulder, Colorado. The two government agencies have been studying Arctic Sea ice from space since nineteen seventy-nine. One of the scientists says the past six years have shown the lowest Arctic sea ice cover ever measured.
VOICE TWO: The study found an average ice cover of about fifteen million square kilometers in March. That is seven hundred thirty kilometers above the record low set three years ago. But it represents a loss of about five hundred ninety thousand kilometers from the yearly average between nineteen seventy-nine and two thousand.
Scientists say ninety percent of all Arctic sea ice is only one or two years old. This is up from forty to sixty percent in the nineteen nineties. The newer ice, experts say, is less resistant to melting during the summer months.
VOICE ONE: The amount of ice cover and its thickness are two measures of the health of the Arctic Sea. Arctic sea ice is important because it throws sunlight back into space, keeping the sea cold. The ice also cools the air. But when the ice melts, the sun warms ocean waters.
Walter Meier is a scientist with the National Snow and Ice Data Center. He says a warmer Arctic and thinner sea ice changes the balance between the normally cold Arctic and warmer areas. He says changes to the ice cover also affect Arctic wildlife and people who depend on the local environment. The melting has already threatened native animals like the polar bear. Arctic melting could also affect Earth's climate. Professor Meier also says the possibility of ships being able to move through newly unfrozen parts of the Arctic could lead to losses of natural resources. He says the competition this could create may also threaten international security.
VOICE TWO: The study follows a separate report by the United States Oceanic and Atmospheric Administration and the Joint Institute for the Study of Atmosphere and Ocean. That study used computers and current ice-level information to predict future ice levels. The findings predicted that most of the Arctic's summer ice could disappear in thirty years. Parts of Antarctica are also believed to be melting because of climate change. Satellite images show an ice bridge that held a huge Antarctic ice shelf in place recently broke apart.
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