연결 가능 링크

빙산은 영원히 사라지는가 (melting polar ice)


INTRODUCTION:
Some scientists have long believed in the global warming theory -- that the air and water are getting warmer due to the burning of fossil fuels and industrial pollutants. All of this is, according to experts, contributing to a "greenhouse effect". Now, there is additional evidence of warmer temperatures -- the summer ice pack around the North Pole is melting away at what they say is an alarming rate. V-O-A's Ernest Leong reports.

NARRATOR:
The Arctic Ocean's frozen surface has been called the northern hemisphere's "summertime air conditioner". These vast ice fields have always cooled the summer winds blowing southwards, and are important in keeping the northern hemisphere from heating up too much.

Normally a part of the ice melts in the summer and re-forms in winter. But since the 1970's, nearly 30% of the Arctic sea-ice has melted away in summer. At this rate, some believe the ice could completely melt away one summer before the end of the century. NASA researcher Dr. Waleed Abdalati.

DR. WALEED ABDALATI, NASA RESEARCHER:
"In 2005, it's the lowest on record. We've watched that [ice] retreat year after year. There's really something going on."

This year, 1.3 million square kilometers more ice has melted than in an average year. Less ice means less white surface to reflect the sun's heat away from Earth, and more dark open water to absorb that heat. This, in turn, speeds up the melting process for the remaining ice.

Some scientists theorize that as the water temperature increases, so does the likelihood of violent weather, such as hurricanes.

DR. WALEED ABDALATI, NASA RESEARCHER:
"So this is an unstable system."

An unstable system that has an immediate effect on those who live in the Arctic region. This whale hunter made a surprising discovery when he checked the whale meat in his ice cellar.

WHALE HUNTER:
"The skin and the blubber should be frozen solid. It's thawing out already."

In the past, any ground in the North Pole deeper than 1.2 meters was frozen solid. This hunter's cellar is twice that depth -- 2.4 meters underground.

The Arctic ice protects the shore from the open sea. As that ice retreats, villages such as this one must move to avoid getting washed into the ocean.

The retreating ice also affects the wildlife. Warmer weather birds, such as the black guillemots and puffins, are migrating farther north. And polar bears are starving as their hunting ground, the frozen ocean surface, is shrinking.

For most of us, evidence of a warmer world can be found in hotter summers and more violent weather. Those living on the frozen fields, in the "summer air conditioner," can watch their world melt away before their eyes.

[관련기사]

북극의 빙하 면적이 4년연속 빠른 속도로 축소되고 있는 가운데 과학자들은 이런 추세대로라면, 금세기 말 이전에 북극에 얼음이 남아있지 않게 될 수도 있다고 우려하고 있습니다.
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미국의 인공 위성 자료 결과, 2002년이래 시베리아 북부와 알라스카 지역의 얼음이 봄철에도 이례적으로 녹고 있다는 사실이 밝혀졌습니다.

미국 콜로라도 대학교부설, 국립 설빙 자료 센터는 이같은 현상은 올들어 북극 빙하 지역 전지역으로 확대됐다고 말했습니다.

국립 설빙 자료 센터의 테드 스캄보스 연구원은 이는 여름철의 빙하감소 속도가 더욱 가속화되고 있음을 말해주는 것이라고 말했습니다.

스캄보스 연구원은 여름철 북극의 빙하 감소 속도는 해마다 경신되면서, 그 이듬해에는 더욱 악화되는 현상을 보이고 있다고 말했습니다.

스캄보스 연구원은 이는 일종의 악순환이라면서 북극의 얼음을 처음 녹이기 시작한다고 가정하면 얼음은 실제 어둡고 탁해지기 시작할 것이라면서 하얀 눈은 햇볕의 85퍼세트를 반사하지만, 이를 녹이게 되면 그 밝기는 60퍼센트로 떨어지게 되는데 그럴 경우 햇볕을 반사하는 양이 줄어들면서 태양빛 에너지를 더 많이 흡수하게 되고 더 많이 녹게 되는 원리라고 설명합니다.

스캄보스 연구원은 또 여름철 북극의 얼음층이 줄어드는 것은 겨울철이 해마다 점점 더 짧아지고 있음을 의미한다고 말했습니다.

보고서는 북극의 빙하를 위성으로 감시한지 25년만에 처음으로 지난해 겨울, 빙하의 면적이 최소로 나타났음을 보여주었습니다.

과학자들은 화석 연료를 연소하는 과정에서 발생하는 오염으로 인한 지구 온난화현상에서 가장 큰 이유를 찾고 있습니다.

이 보고서 역시 북극의 기온이 상승하고 있는데 대해서도 경고하고 있습니다. 지난해, 일단의 국제 과학자들은 이산화 탄소같이 대기권에 있는 온실가스들이 지난 50년간 북극의 온도를 섭씨 3도내지 4도가량 상승하게 만들었다고 지적했습니다.

이들은 또 이같은 추세가 다음세기까지도 계속된다면 육지의 평균 기온은 3도에서 5도, 북극의 경우 최고 7도까지 더 상승할 것이라고 전망했습니다.

이번 보고서 작성을 주도한 미국 국립 기상 협회의 로버트 코렐씨는, 북극의 빙하 면적이 줄어들면서 북극곰과 일부 바다 표범어종이 멸종될지도 모르고 그결과 북극에 살고 있는 사람들은 극심한 경제적 피해로 고통을 받게 될 것이라고 말했습니다.

코렐씨는 사실상 북극에서 기후의 변화가 일어나고 있고 이는 지구 생태계에 해로운 영향을 미치고 있다면서, 그곳에 살고 있는 사람들, 동물과 식물들에게 매우 힘겨운 시간이 되고 있다는 확실한 증거들이 있다고 말했습니다.

테드 스캄보스 씨는 북극의 공기는 전세계 기후에 강력한 영향을 미치고 있다고 말했습니다.

스캄보스씨는, 북극과 남극의 찬공기와 적도의 더운 공기가 만나 만드는 바람의 형태에 힘입어 인간주거지의 기상조건이 결정된다는 사실을 지적했습니다. 북극의 온난화는 그동안의 생태계 균형적인 현상을 변화시킵니다.

스캄보스 씨는 근본적 방식으로 그 균형을 바꾸면 북극해의 얼음을 몇달안에 잃게되는 일이 다시 재현될 것이며 중대한 변화를 맞게 될 것이라고 경고하면서 먼저 북극이 더욱 따뜻해지게 될 것이고, 대서양의 따뜻하고 습한 공기가 기후를 조절하면서 지구 곳곳에서도 다른 변화들이 나타날 것이라고 말했습니다. 콜로라도 대학교 연구진의 보고서는 또 북극의 봄철 해빙기가 매년 조금씩 빨라지고 있다고 지적했습니다.

1978년의 인공 위성 자료를 이용해 과학자들은 올해의 해빙은 예년보다 2주 반정도 일찍 시작되면서 새로운 기록을 나타냈다고 말했습니다.

(영문)

Scientists say new U.S. and Canadian satellite images have tracked what they call a stunning reduction in Arctic Sea ice following the northern summer. The shrinkage is far more extensive than normal for the fourth consecutive year. As we hear from VOA's David McAlary in Washington, the researchers say the current rate of decline could mean that the Arctic would be free of ice well before the end of the century.

Since 2002, U.S. satellite data have revealed unusual springtime melting in areas north of Siberia and Alaska. Now, the National Snow and Ice Data Center at the University of Colorado says the trend expanded this year to include the entire Arctic ice pack.

"What it's telling us is that the pace of retreat of ice in summer is accelerating."

This is snow and ice data center researcher Ted Scambos [SCAM-boss]. He says the record Arctic ice sheet reductions each summer are feeding on themselves, making each subsequent year worse.

"It's sort of a vicious circle. What happens is if you start to melt the sea ice up in the Arctic, it actually starts to get darker. Dry, white snow reflects 85 percent of the sunlight that falls on it.

If you start to melt it, though, that brightness goes down to about 60 percent, and so it starts to absorb more energy. Once it gets a little more darker, it starts absorbing more heat, leading to further melting."

Mr. Scambos says the shrinking summer Arctic ice cap means less and less expansion each winter, with less thickness. The new report shows that last winter's recovery was the smallest in a quarter century of satellite monitoring.

The researchers believe the best explanation is a general global warming caused by pollution from burning fossil fuel.

The findings are the latest warning about rising Arctic temperatures. Late last year, an international team of scientists said heat-trapping gases in the atmosphere, such as carbon dioxide, have caused a three to four degree Celsius rise in Arctic temperatures over the last 50 years.

The group predicted a continuation of the trend over the next century with an additional average temperature increase of three to five degrees over land and up to seven degrees over the Arctic Ocean.

The chairman of the panel that wrote the report, Robert Correll of the American Meteorological Society, says that as the Arctic ice cover shrinks more, polar bears and some seal species might become extinct and Arctic peoples will suffer severe economic consequences.

"Climate change is really happening in the Arctic and it is having deleterious effects on many systems. The preponderance of evidence is suggesting that it is creating some very difficult times for the people who live there, for the animals and plants that are residing there."

Ted Scambos at the National Snow and Ice Data Center says Arctic air contributes powerfully to the world's climate. He points out that frigid air at the poles and the heat at the equator create global wind patterns that cause the weather we experience. Arctic warming changes the balance.

"If we start to change that balance in the fundamental way that losing Arctic ice for a few months out of the year would represent, we can expect to see major changes, first in the Arctic, where it will be a lot warmer, and then other changes that would propagate elsewhere in the world as climate adjusts to having a warm and humid patch of air over the Arctic ocean."

The most pronounced global effect of Arctic warming will be rising sea levels, according to Michael McCracken of the U.S.-based non-profit organization the Climate Institute. He says coastlines and other low-lying areas will be threatened with inundation.

"Once we start this melting going, it has the potential for raising sea level very significantly. We're not talking about sea level rise just in the Arctic. We're talking about sea level rise around the globe, so everybody is going to experience it, particularly regions that have low lying areas."

The report from the University of Colorado team says the Arctic spring thaw is coming a little earlier each year. Using a satellite record going back to 1978, the researchers show that this year's melt began two-and-a-half weeks earlier than usual, a new record.

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