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格陵兰岛是地球上最大的岛屿，大部分面积（84％）被冰雪覆盖。格陵兰岛大陆冰川（或称冰盖）面积达180万平方千米，其冰层平均厚度达2 300米，与南极大陆冰盖的平均厚度差不多。格陵兰岛的冰雪总量为300万立方公里，占全球淡水总量的5.4％。由于近年来全球气温变暖，冰山移动及融化速度加快，导致格陵兰岛的冰山崩塌融化。如果格陵兰岛的冰雪全部消融，全球海平面将上升7.5米。看来，人类应该真正关注我们赖以生存的地球了。
Greenland’s glaciers are dumping twice as much ice into the Atlantic Ocean now as five years ago because glaciers are moving and melting more quickly. This could mean oceans will rise even faster than forecast, and rising surface air temperatures appear to be to blame, the researchers report in a issue of the journal Science.
“This change, combined with increased melting, suggests that existing estimates of future rises in sea level are too low,” Julian Dowdeswell of the Scott Polar Research Institute at Britain’s Cambridge University wrote in a commentary. “At 1.7 million square km (656 000 square miles), up to 3 km (nearly two miles) thick and a little smaller than Mexico, the Greenland Ice Sheet would raise global sea level by about 7 meters (22 feet) if it melted completely.”
The study did not explore what is causing the rising air temperatures in Greenland, but most scientists agree that human activity, notably the burning of fossil1 fuels, is playing an important role in global warming. Eric Rignot of NASA’s Jet Propulsion Laboratory at the California Institute of Technology and Pannir Kanagaratnam of the University of Kansas used satellite data to track the movement of Greenland’s glaciers, which slide slowly down to the sea and deposit ice.
They calculated that Greenland contributes about 0.02 inch (half a millimeter) to the annual 0.1 inch (3 mm) rise in global sea levels. Since 1996, southeast Greenland’s outlet2 glaciers have been flowing more quickly, and since 2000, glaciers farther north have also sped up. Rignot and Kanagaratnam found that ice loss due to glacier flow has increased from 12 cubic3 miles of ice loss per year in 1996 to 36 cubic miles of ice loss per year in 2005.
“It takes a long time to build and melt an ice sheet, but glaciers can react quickly to temperature changes,” Rignot said in a statement. He said the models now used to predict how much ice Greenland will lose, and what effect that will have on sea levels, may underestimate4 the outcome.
Rising air temperatures are clearly a factor, the researchers told a meeting of the American Association for the Advancement of Science, which publishes Science. Over the last 20 years, the air temperature in southeast Greenland has risen by 5.4 degrees F (3 degrees C). Warmer air lubricates5 the bottoms of glaciers, helping them slide faster. “Climate warming can work in different ways, but generally speaking, if you warm up the ice sheet, the glacier will flow faster,” said Rignot. And it may melt even more quickly in years to come, he added. “The southern half of Greenland is reacting to what we think is climate warming. The northern half is waiting, but I don’t think it’s going to take long,” Rignot said.
由于气温变暖，冰河移动及融化速度加快，格陵兰岛的冰河崩塌融化，向大西洋倾注的冰量是五年前的两倍。这意味着海平面上升的速度比人们预想的要快。似乎大气表层的温度升高是导致这一现象出现的元凶——《科学》杂志的研究人员在一篇报道中说。
“这种变化伴随着融化速度的加快，这意味着目前人们低估了未来海平面上升的情况。” 英国剑桥大学斯科特极地研究院的朱利安·道兹威尔在一篇评论中说，“面积约为170万平方千米（65.6万平方英里），厚度为3 000（接近2英里），比墨西哥的面积略小的格陵兰冰盖如果完全融化，海平面将会升高7米（22英尺）。”
这项研究并没有探究什么是导致格陵兰岛的空气温度上升的原因，但众多科学家认为，人类的行为，特别是石化燃料的燃烧在全球变暖这一现象中扮演着重要的作用。加州理工学院的美国宇航局喷气推进实验室的埃里克·里格诺特和美国堪萨斯大学的潘尼尔·卡那格拉特纳利用卫星数据对格陵兰岛冰河的运动进行了监控研究。结果表明，它缓缓地滑向大海并把冰河沉积下来。
他们计算出：全球海平面每年升高0.1英寸（3毫米），就有0.02英寸（半毫米）是由于格陵兰岛冰河融化所致。1996年，格林兰东南部冰河的漂流速度就已经加快；2000年起，位置更靠北的冰河也开始加速。埃里克·里格诺特和卡那格拉特纳发现，由于冰河移动所造成的冰川流失从1996年的每年12立方英里上升到了2005年的每年36立方英里。
对此，利格诺特在一份声明中指出：“冰河的形成和融化需要很长时间，但是它们会对温度的变化做出快速反应。”他还说，目前人们用来预测格陵兰岛冰河消融情况以及它对海平面产生何种影响的模型可能会低估真实结果。
研究人员在出版《科学》杂志的美国科学探索联盟的一次会议上宣布，很明显气温升高是一个原因。在过去20年中，格陵兰东南部的气温提高了5.4华氏度（约3摄氏度）；温暖的空气让冰河的底座变得更光滑，冰河的移动速度从而也更快了。“气候变暖会以多种形式表现出来，但基本上如果冰盖遇到的温度升高，冰河的漂流速度会更快。”里格诺特说。他还补充说，在未来的几年中，融化速度也会更快。“格陵兰南部现在的情况就是在对我们所认为的气候变暖做出反应。北部虽然还没有发生这样的情况，但我想这种状况不会持续很长时间了。”里格诺特说。
大河 摘译自Science
Greenland’s glaciers are dumping twice as much ice into the Atlantic Ocean now as five years ago because glaciers are moving and melting more quickly. This could mean oceans will rise even faster than forecast, and rising surface air temperatures appear to be to blame, the researchers report in a issue of the journal Science.
“This change, combined with increased melting, suggests that existing estimates of future rises in sea level are too low,” Julian Dowdeswell of the Scott Polar Research Institute at Britain’s Cambridge University wrote in a commentary. “At 1.7 million square km (656 000 square miles), up to 3 km (nearly two miles) thick and a little smaller than Mexico, the Greenland Ice Sheet would raise global sea level by about 7 meters (22 feet) if it melted completely.”
The study did not explore what is causing the rising air temperatures in Greenland, but most scientists agree that human activity, notably the burning of fossil1 fuels, is playing an important role in global warming. Eric Rignot of NASA’s Jet Propulsion Laboratory at the California Institute of Technology and Pannir Kanagaratnam of the University of Kansas used satellite data to track the movement of Greenland’s glaciers, which slide slowly down to the sea and deposit ice.
They calculated that Greenland contributes about 0.02 inch (half a millimeter) to the annual 0.1 inch (3 mm) rise in global sea levels. Since 1996, southeast Greenland’s outlet2 glaciers have been flowing more quickly, and since 2000, glaciers farther north have also sped up. Rignot and Kanagaratnam found that ice loss due to glacier flow has increased from 12 cubic3 miles of ice loss per year in 1996 to 36 cubic miles of ice loss per year in 2005.
“It takes a long time to build and melt an ice sheet, but glaciers can react quickly to temperature changes,” Rignot said in a statement. He said the models now used to predict how much ice Greenland will lose, and what effect that will have on sea levels, may underestimate4 the outcome.
Rising air temperatures are clearly a factor, the researchers told a meeting of the American Association for the Advancement of Science, which publishes Science. Over the last 20 years, the air temperature in southeast Greenland has risen by 5.4 degrees F (3 degrees C). Warmer air lubricates5 the bottoms of glaciers, helping them slide faster. “Climate warming can work in different ways, but generally speaking, if you warm up the ice sheet, the glacier will flow faster,” said Rignot. And it may melt even more quickly in years to come, he added. “The southern half of Greenland is reacting to what we think is climate warming. The northern half is waiting, but I don’t think it’s going to take long,” Rignot said.
由于气温变暖，冰河移动及融化速度加快，格陵兰岛的冰河崩塌融化，向大西洋倾注的冰量是五年前的两倍。这意味着海平面上升的速度比人们预想的要快。似乎大气表层的温度升高是导致这一现象出现的元凶——《科学》杂志的研究人员在一篇报道中说。
“这种变化伴随着融化速度的加快，这意味着目前人们低估了未来海平面上升的情况。” 英国剑桥大学斯科特极地研究院的朱利安·道兹威尔在一篇评论中说，“面积约为170万平方千米（65.6万平方英里），厚度为3 000（接近2英里），比墨西哥的面积略小的格陵兰冰盖如果完全融化，海平面将会升高7米（22英尺）。”
这项研究并没有探究什么是导致格陵兰岛的空气温度上升的原因，但众多科学家认为，人类的行为，特别是石化燃料的燃烧在全球变暖这一现象中扮演着重要的作用。加州理工学院的美国宇航局喷气推进实验室的埃里克·里格诺特和美国堪萨斯大学的潘尼尔·卡那格拉特纳利用卫星数据对格陵兰岛冰河的运动进行了监控研究。结果表明，它缓缓地滑向大海并把冰河沉积下来。
他们计算出：全球海平面每年升高0.1英寸（3毫米），就有0.02英寸（半毫米）是由于格陵兰岛冰河融化所致。1996年，格林兰东南部冰河的漂流速度就已经加快；2000年起，位置更靠北的冰河也开始加速。埃里克·里格诺特和卡那格拉特纳发现，由于冰河移动所造成的冰川流失从1996年的每年12立方英里上升到了2005年的每年36立方英里。
对此，利格诺特在一份声明中指出：“冰河的形成和融化需要很长时间，但是它们会对温度的变化做出快速反应。”他还说，目前人们用来预测格陵兰岛冰河消融情况以及它对海平面产生何种影响的模型可能会低估真实结果。
研究人员在出版《科学》杂志的美国科学探索联盟的一次会议上宣布，很明显气温升高是一个原因。在过去20年中，格陵兰东南部的气温提高了5.4华氏度（约3摄氏度）；温暖的空气让冰河的底座变得更光滑，冰河的移动速度从而也更快了。“气候变暖会以多种形式表现出来，但基本上如果冰盖遇到的温度升高，冰河的漂流速度会更快。”里格诺特说。他还补充说，在未来的几年中，融化速度也会更快。“格陵兰南部现在的情况就是在对我们所认为的气候变暖做出反应。北部虽然还没有发生这样的情况，但我想这种状况不会持续很长时间了。”里格诺特说。
大河 摘译自Science