南极洲和格陵兰岛正在失去成千上万亿吨的冰
南极洲和格陵兰岛正在失去成千上万亿吨的冰
As the climate has warmed, Antarctica and Greenland have lost enough ice in the last 16 years to fill Lake Michigan, according to results from a new NASA mission.
美国国家航空航天局(NASA)一项新任务的结果显示，随着气候变暖，南极洲和格陵兰岛在过去16年里失去了足以填满密歇根湖的冰。
And drove up sea levels around the world.
这导致全球海平面上升。
The findings show how the massive ice sheets at the far ends of the planet will affect millions of people on coastlines everywhere.
这些发现表明，地球远端巨大的冰原将如何影响世界各地海岸线上的数百万人。
"It will reach us eventually here, even though it's really far away and hard to think about," said Helen Fricker, a glaciologist with the Scripps Institution of Oceanography at the University of California-San Diego. "How much ice we are going to lose, and how quickly we are going to lose it, is a really key thing that needs to be understood, so that we can plan."
加州大学圣地亚哥分校斯克里普斯海洋学研究所的冰川学家海伦·弗里克说：“它最终会到达我们这里，尽管它真的很遥远，很难想象。”我们将失去多少冰，以及我们将以多快的速度失去它，这确实是一个需要了解的关键问题，这样我们才能制定计划。”
The data was measured by ICESat-2. a NASA satellite launched in 2018. which uses lasers to take detailed measurements of ice. It's the sequel to a previous satellite, ICESat, that gathered data from 2003 to 2009. Using information from both missions, researchers were able to quantify the massive scale of melting.
这些数据是由NASA于2018年发射的ICESat-2卫星测量的，该卫星使用激光对冰进行详细测量。这是在前一颗卫星ICESat之后发射的，ICESat收集了2003年至2009年的数据。利用来自这两个任务的信息，研究人员能够量化大规模的融化。
The mission is also shedding light on what's driving the melting. Antarctica's ice, now sitting on land, makes a slow progression to the ocean. When it reaches the coast, it floats, creating ice shelves skirting around the continent. Those shelves are natural barriers that slow the rate of ice loss, but as they melt in a warming ocean, that barrier is shrinking.
这次任务也揭示了导致冰川融化的原因。南极洲的冰现在位于陆地上，缓慢地向海洋移动。当它到达海岸时，它会漂浮起来，形成环绕大陆的冰架。这些冰架是减缓冰融化速度的天然屏障，但随着它们融化在不断变暖的海洋中，这一屏障正在缩小。
"It's like an apple tart and the ice shelves are like the wall of pastry around the edges of the tart," says Fricker. "And if those walls are too thin or they're not baked well enough, then the filling will ooze out."
弗里克说：“它就像一个苹果馅饼，冰架就像馅饼边缘的糕点墙。”如果这些墙太薄或者烤得不够好，那么馅料就会渗出来。”
Warmer air temperatures around Greenland are directly melting its ice, as well as causing ice to calve off into the ocean. Greenland holds enough ice to raise global sea levels as much as 23 feet and other NASA studies have found melting is accelerating.
格陵兰岛周围较高的气温直接融化了它的冰，并导致冰裂入海洋。格陵兰岛拥有足够的冰，足以使全球海平面上升23英尺，美国宇航局的其他研究发现，融化正在加速。
Combined, melting ice from both places has caused about half an inch of sea level rise, around a third of what's been seen over the 16-year period.
这两个地方融化的冰加在一起，导致海平面上升了大约半英寸，大约是过去16年里所看到的上升幅度的三分之一。
Sea levels are also rising because warmer water expands. "The ocean expands first and then the ice responds to the warming ocean and warming air," said Robin Bell, a research professor at the Lamont-Doherty Earth Observatory.
由于水温升高，海平面也在上升。“海洋首先膨胀，然后冰对海洋变暖和空气变暖做出反应，”拉蒙特-多尔蒂地球天文台的研究教授罗宾·贝尔说。
With ICESat-2 still circling the planet, scientists say it will continue to provide crucial information, helping refine their understanding of how the planet is changing.
由于ICESat-2仍在围绕着地球运转，科学家们表示，它将继续提供关键信息，帮助他们进一步了解地球是如何变化的。
"We've all been waiting for this new dataset," Bell said. "Our goal is to be able to tell every coastal community what they can plan on [in] the coming decades. To be able to do that, we both need to measure how the ice is changing but also understand better why it's changing."
“我们一直在等待这个新的数据集，”贝尔说。“我们的目标是能够告诉每个沿海社区，他们在未来几十年可以计划什么。为了做到这一点，我们都需要测量冰是如何变化的，同时也需要更好地理解为什么会变化。”
With oceans predicted to rise as much as 8 feet by the end of the century, governments around the world are looking for detailed projections of how fast that will happen.
据预测，到本世纪末，海平面将上升8英尺，世界各国政府正在寻找有关海平面上升速度的详细预测。
"There's a lot of infrastructure and airports and people that live right on the ocean," Fricker said. "And these people are going to feel the effects of sea level rise that's resulted because the ice sheets have melted."
弗里克说:“这里有很多基础设施和机场，人们就住在海边。“这些人将会感受到由于冰盖融化导致的海平面上升的影响。”
