The End OF The World

【王潔予╱綜合外電報導】拜全球暖化之賜，人類尋求逾500年的北極圈「西北通道」即將開通。歐洲太空總署前天發布衛星空照圖，加拿大北極海沿岸永凍層厚度融至史上新低，西北通道上月已全面開通，歐美船隻今後毋須繞道蘇伊士運河或巴拿馬運河，能夠以更短的時間抵達遠東。 

歐洲太空總署（European Space Agency，簡稱ESA）環境衛星Envisat，本月初拍到加拿大北極海沿岸海冰面積，僅剩300萬平方公里（約83個台灣大），創下人類1978年藉衛星觀測北極以來新低。丹麥國家太空中心科學家派德森指，「過去10年，北極海冰每年平均減少10萬平方公里，近1年來縮小100萬平方公里已達巔峰。」
這項變化對人類的影響是，從美國波弗特海（Beaufort Sea）到加拿大巴芬島（Baffin Island）北端的狹長「西北通道」（Northwest Passage）可望提前開通。 


北極海冰山融化使西北通道完全開通，可從大西洋西岸經北極海直通太平洋。圖為歐洲太空總署拍攝的北極海衛星空照圖。法新社

新航道夏季可通行
英王亨利七世曾於1497年派義大利探險家卡波特（John Cabot）尋找這條航道。科學家現在估計，此通道夏季已可通行，最快2025年變得一年四季都萬里無冰。此捷徑一旦開通，歐亞航行距離將比通過巴拿馬運河少9000公里。
儘管聯合國科學家警告，北極是地球面臨氣候暖化時最易受創的地區，但西北通道開通帶來的商業價值，令周邊國家難以抗拒，其中最大受益者之一是加拿大，溫哥華水道有機會變成「新巴拿馬運河」。
霍斯舒灣（Horseshoe Bay）海業集團負責人斯皮爾斯（Joseph Spears）在加拿大一個海事會議上說，最快在明年，加拿大北極海地區就可作為商船貿易航道。加拿大邱吉爾航務開發公司執行長朱爾表示：「我們不樂見全球暖化，但以船務發展觀點來看，我們必須搭上這班順風車。」 

初期須配有破冰船
目前，各國郵輪或科學考察船會趁夏季通過西北通道，但受限結冰期長，商用航運無法固定出航，海冰融化後，情況將隨之轉變。不過，美國航太總署日前表示，西北通道在開放初期不見得利於航行。該航線地處偏遠，距北極中心點約1930公里，北極圈還在它南邊800公里處，航行者若非配有堅固破冰船，很難順利過關。
然而，北極海冰加速融化已成趨勢。聯合國跨政府氣候變遷小組今年的評估報告指出，海洋「反照率」（albedo）降低加快海冰融化。表面光亮的海冰原可將日光反射回空中，海冰面積減少，日光被顏色較深的海水吸收，非但使融冰速度加快，新冰也難以成形。 

西北通道航線示意圖
西北通道開通後，由東北亞至美洲東北岸及歐洲的海運航線可不須再經巴拿馬運河，預估可節省9000公里航程，圖為由日本東京至美國波士頓分別走太平洋經巴拿馬運河，及行經北極海西北通道兩條路線。因地球緯線以赤道最長，從赤道向兩極，緯線逐漸縮短，因此在地圖上看來兩條路線距離相差不大，但實際距離以經由北極海的路線較短。資料來源：綜合外電 


北極融冰加快事件簿
2006年12月 美國地球物理學會警告，北極2040年夏季將無積雪，到2060年9月不會再有冰雪。
2007年8月 美國國家冰雪數據中心表示，北極夏日冰比常年平均厚度薄30%，今年將出現史上最薄冰層。
2007/09/04 美國科學家瑟雷茲發表數據警告，北極冰山將在2030年夏季融化殆盡。
2007/09/07 美國地質調查所公布報告，因全球暖化導致北極冰面融化，2050年北極熊數量恐將減少2/3。
2007/09/14 歐洲太空總署稱北極海洋冰塊以破紀錄速率縮減，「西北通道」現已全面開通，較原估2012至2080年更早。
資料來源：綜合外電 

各國競相宣示北極主權
2007/08/02 俄羅斯潛艇「和平一號」將一面防鏽鈦金屬製國旗插在4261公尺深的北極海底。
2007/08/10 加拿大總理哈波宣布，將位於北極圈一座軍事基地翻新為駐北極部隊訓練中心，並在北極圈興建軍用深水港。
2007/08/12 丹麥科學團隊出發到北極，在北極海域蒐集資料，證明2千多公里長的羅蒙諾索夫海嶺為丹麥領土格陵蘭島大陸棚延伸。
2007/08/14 多架可攜帶核彈頭俄羅斯戰略轟炸機在北極進行5天軍演。天然資源部批准設立名為「俄羅斯北極區」的自然保育區。
2007/08/17 美國海岸防衛隊「西力號」破冰船出發到北極繪製海底地圖，確定阿拉斯加北部大陸棚延伸範圍。
資料來源：《蘋果》資料室 


海底藏石油 五國爭主權

兵家必爭
北極海冰層厚度達數公里至數十公里，因此難以確定海床下資源分布，且開採成本極高，使北極乏人問津，如今原本常年冰封的「西北通道」全面開通，政治上來說，讓北極海成為本世紀兵家必爭之地，料將使得俄羅斯及美國等周邊國家對北極主權的爭議白熱化，加速各國對該區蘊藏資源爭奪戰。

俄國派潛艇插國旗
據《聯合國海洋法公約》，沿海國家擁有距該國海岸200浬以內大陸棚海床，範圍以外海床若能證明是海底大陸棚延伸，仍可主張主權，因此俄羅斯、美國、加拿大、丹麥和挪威五國積極爭取。上月2日俄羅斯派出潛艇，將一面防鏽鈦金屬製國旗插在北極海底，宣示主權，掀起最近一波主權競賽，兩周後又在北極進行空中軍演，展現野心勃勃的企圖心。
美國與丹麥分別派員到北極偵測，要證明該國所屬大陸棚，與北極海底的羅蒙諾索夫海嶺相連。加拿大也宣布要在北極圈興建新軍事基地，而該國宣稱擁有西北通道的主張，美國上月21日已明確表示不同意，堅稱西北通道是國際航道。編譯張翠蘭 


Yahoo! News - Sep 16

Arctic ice melt opens Northwest Passage 
By JAMEY KEATEN, Associated Press Writer
Sun Sep 16, 12:07 AM ET

PARIS - Arctic ice has shrunk to the lowest level on record, new satellite images show, raising the possibility that the Northwest Passage that eluded famous explorers will become an open shipping lane. 

The European Space Agency said nearly 200 satellite photos this month taken together showed an ice-free passage along northern Canada, Alaska and Greenland, and ice retreating to its lowest level since such images were first taken in 1978.

The waters are exposing unexplored resources, and vessels could trim thousands of miles from Europe to Asia by bypassing the Panama Canal. The seasonal ebb and flow of ice levels has already opened up a slim summer window for ships.

Leif Toudal Pedersen, of the Danish National Space Center, said that Arctic ice has shrunk to some 1 million square miles. The previous low was 1.5 million square miles, in 2005.

"The strong reduction in just one year certainly raises flags that the ice (in summer) may disappear much sooner than expected," Pedersen said in an ESA statement posted on its Web site Friday.

Pedersen said the extreme retreat this year suggested the passage could fully open sooner than expected — but ESA did not say when that might be. Efforts to contact ESA officials in Paris and Noordwik, the Netherlands, were unsuccessful Saturday.

A U.N. panel on climate change has predicted that polar regions could be virtually free of ice by the summer of 2070 because of rising temperatures and sea ice decline, ESA noted.

Russia, Norway, Denmark, Canada and the United States are among countries in a race to secure rights to the Arctic that heated up last month when Russia sent two small submarines to plant its national flag under the North Pole. A U.S. study has suggested as much as 25 percent of the world's undiscovered oil and gas could be hidden in the area.

Environmentalists fear increased maritime traffic and efforts to tap natural resources in the area could one day lead to oil spills and harm regional wildlife.

Until now, the passage has been expected to remain closed even during reduced ice cover by multiyear ice pack — sea ice that remains through one or more summers, ESA said.

Researcher Claes Ragner of Norway's Fridtjof Nansen Institute, which works on Arctic environmental and political issues, said for now, the new opening has only symbolic meaning for the future of sea transport.

"Routes between Scandinavia and Japan could be almost halved, and a stable and reliable route would mean a lot to certain regions," he said by phone. But even if the passage is opening up and polar ice continues to melt, it will take years for such routes to be regular, he said.

"It won't be ice-free all year around and it won't be a stable route all year," Ragner said. "The greatest wish for sea transportation is streamlined and stable routes."

"Shorter transport routes means less pollution if you can ship products from A to B on the shortest route," he said, "but the fact that the polar ice is melting away is not good for the world in that we're losing the Arctic and the animal life there."

The opening observed this week was not the most direct waterway, ESA said. That would be through northern Canada along the coast of Siberia, which remains partially blocked.

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Associated Press Writer Louise Nordstrom in Stockholm, Sweden, contributed to this report.

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On the Net:

http://www.esa.int/esaCP/SEMYTC13J6F_index_1.html