南極洲和格陵蘭島正在失去成千上萬億噸的冰

南極洲和格陵蘭島正在失去成千上萬億噸的冰

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.

美國國家航空航天局(NASA)一項(xiàng)新任務(wù)的結(jié)果顯示，隨著氣候變暖，南極洲和格陵蘭島在過去16年里失去了足以填滿密歇根湖的冰。

And drove up sea levels around the world.

這導(dǎo)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.

這些發(fā)現(xiàn)表明，地球遠(yuǎn)端巨大的冰原將如何影響世界各地海岸線上的數(shù)百萬人。

"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."

加州大學(xué)圣地亞哥分校斯克里普斯海洋學(xué)研究所的冰川學(xué)家海倫·弗里克說：“它最終會(huì)到達(dá)我們這里，盡管它真的很遙遠(yuǎn)，很難想象。”我們將失去多少冰，以及我們將以多快的速度失去它，這確實(shí)是一個(gè)需要了解的關(guān)鍵問題，這樣我們才能制定計(jì)劃。”

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.

這些數(shù)據(jù)是由NASA于2018年發(fā)射的ICESat-2衛(wèi)星測量的，該衛(wèi)星使用激光對冰進(jìn)行詳細(xì)測量。這是在前一顆衛(wèi)星ICESat之后發(fā)射的，ICESat收集了2003年至2009年的數(shù)據(jù)。利用來自這兩個(gè)任務(wù)的信息，研究人員能夠量化大規(guī)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.

這次任務(wù)也揭示了導(dǎo)致冰川融化的原因。南極洲的冰現(xiàn)在位于陸地上，緩慢地向海洋移動(dòng)。當(dāng)它到達(dá)海岸時(shí)，它會(huì)漂浮起來，形成環(huán)繞大陸的冰架。這些冰架是減緩冰融化速度的天然屏障，但隨著它們?nèi)诨诓粩嘧兣暮Ｑ笾?，這一屏障正在縮小。

"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."

弗里克說：“它就像一個(gè)蘋果餡餅，冰架就像餡餅邊緣的糕點(diǎn)墻。”如果這些墻太薄或者烤得不夠好，那么餡料就會(huì)滲出來。”

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.

格陵蘭島周圍較高的氣溫直接融化了它的冰，并導(dǎo)致冰裂入海洋。格陵蘭島擁有足夠的冰，足以使全球海平面上升23英尺，美國宇航局的其他研究發(fā)現(xiàn)，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.

這兩個(gè)地方融化的冰加在一起，導(dǎo)致海平面上升了大約半英寸，大約是過去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.

由于水溫升高，海平面也在上升。“海洋首先膨脹，然后冰對海洋變暖和空氣變暖做出反應(yīng)，”拉蒙特-多爾蒂地球天文臺(tái)的研究教授羅賓·貝爾說。

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仍在圍繞著地球運(yùn)轉(zhuǎn)，科學(xué)家們表示，它將繼續(xù)提供關(guān)鍵信息，幫助他們進(jìn)一步了解地球是如何變化的。

"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."

“我們一直在等待這個(gè)新的數(shù)據(jù)集，”貝爾說。“我們的目標(biāo)是能夠告訴每個(gè)沿海社區(qū)，他們在未來幾十年可以計(jì)劃什么。為了做到這一點(diǎn)，我們都需要測量冰是如何變化的，同時(shí)也需要更好地理解為什么會(huì)變化。”

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.

據(jù)預(yù)測，到本世紀(jì)末，海平面將上升8英尺，世界各國政府正在尋找有關(guān)海平面上升速度的詳細(xì)預(yù)測。

"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."

弗里克說:“這里有很多基礎(chǔ)設(shè)施和機(jī)場，人們就住在海邊。“這些人將會(huì)感受到由于冰蓋融化導(dǎo)致的海平面上升的影響。”