格陵蘭島現(xiàn)在的融冰速度是上世紀90年代的7倍

格陵蘭島現(xiàn)在的融冰速度是上世紀90年代的7倍

The Greenland ice sheet's losses have accelerated so fast since the 1990s it is now shedding more than seven times as much ice each year, according to 89 scientists who use satellites to study the area.

89名使用衛(wèi)星研究該地區(qū)的科學家表示，自上世紀90年代以來，格陵蘭冰蓋的消融速度如此之快，現(xiàn)在每年的消融量是以前的7倍多。

The sheet's total losses nearly doubled each decade, from 33 billion tons per year in the 1990s to an average now of 254 billion tons annually. Since 1992, nearly 4 trillion tons of Greenland ice have entered the ocean, the new analysis found, equivalent to roughly a centimeter of global sea-level rise.

這個島的總損失幾乎每十年翻一番，從1990年代的每年330億噸增加到現(xiàn)在的平均每年2540億噸。新的分析發(fā)現(xiàn)，自1992年以來，近4萬億噸的格陵蘭冰流入海洋，大約相當于全球海平面上升一厘米。

While a centimeter may not sound like much, that uptick is already affecting millions.

雖然一厘米聽起來不多，但這種上升已經(jīng)影響了數(shù)百萬人。

The results, from a scientific group called the Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE), were published Tuesday in the journal Nature.

研究結果發(fā)表在周二的《自然》雜志上。

The research suggests an alarming pace of change for the Earth's second-largest body of ice, which could theoretically drive more than 20 feet (6 metres) of sea-level rise over a millennium.

這項研究表明，作為地球上第二大的冰體，其變化速度之快令人擔憂，從理論上講，這將導致海平面在一千年內上升超過20英尺(6米)。

The recent Greenland losses, the experts suggest, match a more dire sea-level projection outlined by the United Nations' chief climate science body, the Intergovernmental Panel on Climate Change. Under that high-end scenario, Greenland could contribute about 16 centimeters, or around half a foot, to ocean levels by 2100.

專家們認為，最近格陵蘭島的損失與聯(lián)合國主要氣候科學機構政府間氣候變化專門委員會(Intergovernmental Panel on climate Change，簡稱ipcc)提出的更可怕的海平面預測相符。在這種高端情景下，到2100年，格陵蘭島可能為海平面貢獻約16厘米，或約半英尺。

Much more sea-level rise would then come from melting in Antarctica and smaller glaciers around the world, along with the expansion of ocean water that stems from warmer temperatures.

更多的海平面上升將來自于南極洲的融化和世界各地更小的冰川，以及由于溫度升高而導致的海水擴張。

It is not yet clear whether these other components of the sea-level equation are also following the high end, or worst-case, path, however, and the current study was focused only on Greenland. (While Greenland is the biggest contributor to sea-level rise at the present moment, Antarctica ultimately has a larger long-term potential to raise seas.)

然而，目前尚不清楚的是，海平面公式的其他組成部分是否也遵循高端路線，或最壞情況，目前的研究只集中在格陵蘭島。(雖然格陵蘭是目前海平面上升的最大貢獻者，但南極洲最終有更大的長期海平面上升潛力。)

Sea-level rise would only continue — and, perhaps, accelerate further — after 2100.

2100年后，海平面只會繼續(xù)上升，而且可能進一步加速。

Greenland is the world's largest island, covered with a continuous sheet of ice produced by many thousands of years of snowfall. The ice sheet's size rivals that of Alaska, and its center is well over a mile thick.

格陵蘭島是世界上最大的島嶼，覆蓋著由數(shù)千年降雪形成的連續(xù)冰層。冰蓋的大小堪比阿拉斯加，其中心厚達一英里多。

The ice flows outward under its own weight toward the ocean, but because of Greenland's mountainous and rocky coastline, it usually reaches the sea in fingerlike glaciers that extend outward through fjords. These fjords are partially submerged valleys, which were themselves excavated over vast stretches of geological time by the glaciers' movement.

冰在自身重量的作用下向外流向海洋，但由于格陵蘭島多山和多巖石的海岸線，它通常通過峽灣向外延伸的指狀冰川到達海洋。這些峽灣部分是被淹沒的山谷，是冰川運動在漫長的地質時期中挖掘出來的。

Several large glaciers account for the biggest ice losses — with Jakobshavn Glacier, in central Greenland, leading the way. But there are hundreds of glaciers overall, and now more are losing ice as warming seas come in contact with them through the fjords.

幾個巨大的冰川造成了最大的冰川損失，其中位于格陵蘭島中部的雅各布港冰川首當其沖。但總體上有數(shù)百個冰川，現(xiàn)在隨著變暖的海洋通過峽灣與它們接觸，更多的冰川正在消融。

The ice sheet itself is also being exposed to warming air temperatures. Most of Greenland has warmed by more than 2 degrees Celsius (3.6 degrees Fahrenheit) already, compared with the late 19th century, according to a Washington Post analysis of the globe's fastest-warming regions.

冰蓋本身也暴露在變暖的氣溫下。根據(jù)《華盛頓郵報》對全球變暖最快地區(qū)的分析，與19世紀末相比，格陵蘭島大部分地區(qū)已經(jīng)變暖了2攝氏度(3.6華氏度)以上。

That is double the global average rate of warming.

這是全球平均變暖速度的兩倍。