|
The ancient frozen dome cloaking Greenland is so vast that pilots have crashed into what they thought was a cloud bank spanning the horizon. Flying over it, you can scarcely imagine that it could erode fast enough to dangerously raise sea levels any time soon. 格陵蘭島上覆蓋著的遠古冰穹一望無際，許多飛行員飛過上空時都曾誤以為是地平 線上的云層而俯沖失事。從空中俯瞰的話，很難想象冰穹融化速度是如此之快，過不了多久海平面就將上升至危險水平。 Along the flanks in spring and summer, however, the picture is very different. For an increasing number of warm years, a network of blue lakes and rivulets of melt-water has been spreading ever higher on the icecap. 但是，在春夏季節，冰穹兩側的景象則迥然不同。 隨著溫暖年份不斷增多，融冰形成的藍色冰川湖和溪澗逐漸自下而上侵蝕著冰帽/在冰穹上的海拔越來越高。 The melting surface darkens, absorbing up to four times as much energy from the sun as snow, which reflects sunlight. Natural drainpipes called moulins carry water from the surface into the depths, in some places reaching bedrock. 融冰的表層發黑，吸收的太陽熱量是雪的四倍，因為雪可以反射太陽光。冰川壺穴是天然排水管，融冰水通過壺穴從表層一直滲透至底層，在有些地區甚至會到達底部基 巖。 The process slightly, but measurably, lubricates and accelerates the grinding passage of ice towards the sea. 整個過程對冰劃入海洋起著潤滑和加速的作用，雖然過程緩慢，但是作用明顯。 Most important, many glaciologists say, is the break-up of huge semi-submerged clots of ice where some large Greenland glaciers, particularly along the west coast, squeeze through fiords as they meet the warming ocean. As these passages have cleared, this has sharply accelerated the flow of many of these creeping, corrugated and frozen rivers. 在格陵蘭島的一些大型冰川特別是西海岸的冰川在進入逐漸變暖的海洋前勉強穿過峽灣，這時一些大型的半潛入水中的巨大冰體會斷裂開來，許多冰川學家認為這是最重要的一環。當冰川通過峽灣后，這些緩慢流動、泛著波紋的融冰河流動速度將大大加快。 Some glaciologists fear that the rise in seas in a warming world could be much greater than the upper estimate of about 60 centimetres this century made by the Intergovernmental Panel on Climate Change last year. (Seas rose less than 30 centimetres last century.) 去年聯合國政府間氣候變化專家小組曾預測，本世紀海平面升幅上限為約 60厘米， 但是，一些冰川學家擔心，隨著全球變暖不斷加劇，海平面升幅可能會遠遠高于上述預 測。（上世紀，海平面上升幅度不到 30厘米。） （上世紀，海平面上升幅度不到 30厘米。） The panel's assessment did not include factors known to contribute to ice flows but not understood well enough to estimate with confidence. A scientific scramble is under way to clarify whether the erosion of the world's most vulnerable ice sheets, in Greenland and west Antarctica, can continue to accelerate. The effort involves field and satellite analyses and sifting for clues from past warm periods. 專家小組的預測并沒有考慮到那些影響冰流的人類已知但尚未了解透徹的因素，只有對這些因素有了全面認識才能做出準確預測。 現在正在開展一些科考活動，以確定格陵蘭島和南極洲西部等冰川易融地區冰川的融化速度是否會繼續加快，其中包括實地考察、衛星分析以及研究過去地球溫暖周期的變化情況。 Things are definitely far more serious than anyone would have thought five years ago. 現在形勢肯定比各方五年前預估的情況要嚴峻得多。
|
|
|
