The collapse of a major Antarctic ice sheet once caused a “global flood” and scientists now fear it could happen again.

　　南极大冰盖的崩塌曾经引发了一场“全球洪水”，科学家们现在担心这种情况可能再次发生。

　　The devastating collapse caused sea levels to rise between 20 and 30 feet compared to today. The catastrophic sea level rise drowned huge areas of now-dry land.

　　毁灭性的崩塌导致海平面比如今上升了20到30英尺。灾难性上升的海平面淹没了大片现已干涸的土地。

　　This cataclysmic event, described in Science, took place around 125,000 years ago.

　　《科学》杂志描述的这场大灾难发生在大约12.5万年前。

　　At the time, temperatures were only slightly warmer than today, but sea levels were significantly higher.

　　当时，气温仅比如今略高，但海平面明显更高。

　　And scientists now believe that the source of the water was the collapse of the West Antarctic Ice Sheet.

　　科学家们现在认为，水来源于崩塌的南极西部冰盖。

　　There are major concerns over the stability of this ice sheet, with studies going back several years warning over a pending “collapse.”

　　人们对这片冰盖的稳定性有很大的担忧，早在几年前就有研究警告说，这片冰盖即将“崩塌”。

　　The base of the ice sheet lies below sea level and is now at risk due to increasingly warm ocean waters.

　　冰盖底部位于海平面以下，由于海水不断变暖而处于危险之中。

　　The worry is that “the West Antarctic Ice Sheet might not need a huge nudge to budge,” Jeremy Shakun, a paleoclimatologist at Boston College, told Science.

　　波士顿学院的古气候学家杰里米·沙肯告诉《科学》杂志，令人担忧的是“南极西部冰盖可能不需要巨大的推动力就能移动”。

　　He warned that the ice mass lost from the sheet in the past two decades may not be a “short-term blip” – but instead the start of a major collapse.

　　他警告说，过去20年里冰盖上的冰消融可能不是一个“短期现象”，而是大崩塌的开始。

　　According to some studies, the ancient ice sheet collapse caused sea levels to rise as quickly as 8 feet a century.

　　根据一些研究，古代冰盖的崩塌导致海平面以每世纪8英尺的速度上升。

　　Worryingly, temperatures were 2 degrees above modern preindustrial levels – and we’re at 1 degree higher than that, today.

　　令人担忧的是，当时的气温比现代前工业时代高2度，而我们如今的气温比那时高1度。

　　Climate scientists have regularly warned that global temperatures rising to 2 degrees could have catastrophic consequences for humanity.

　　气候科学家经常警告说，全球气温上升到高2度可能会给人类带来灾难性的后果。

　　The aim for global leaders and environmentalists is to restrict warming to 1.5 degrees – to avoid dangerous levels of climate change.

　　全球领导人和环保人士的目标是将升温控制在1.5度以内，以避免气候变化达到危险的水平。

　　Scientists pinned the rising sea levels to the ice sheet collapse by investigating Antarctic ice cores.

　　科学家通过对南极冰芯的调查，将海平面上升归咎于冰盖的崩塌。

　　Researchers from the University of Oregon, NASA and others published a detailed paper for the American Geophysical Union, which revealed the truth behind a worrying climate incident from our past.

　　来自俄勒冈大学、美国航空航天局以及其他机构的研究人员为美国地球物理联盟发表了一篇详细的论文，揭示了过去令人担忧的气候事件背后的真相。

　　During the early Eemian period (when sea levels were high), you’d expect to see silt from a number of areas around ice sheets – due to ice-driven erosion.

　　在早期的埃米纪(当时海平面很高)，你可能会看到来自冰盖周围许多地区的淤泥，这是由冰川侵蚀造成的。

　　But there was no evidence of sediments coming from the West Antarctic Ice Sheet in the cores.

　　但没有证据表明这些冰芯中有来自南极西部冰盖的沉积物。

　　The obvious explanation is that the ice sheet simply ceased to exist – or collapsed so much that it couldn’t erode anymore.

　　最明显的解释是冰盖根本就不存在了或者崩塌到再也不能侵蚀的程度了。

　　Sadly, it’s impossible to say with 100 percent certainty that the melting ice sheet sparked enormous sea-level rise.

　　遗憾的是，不能百分之百地肯定是融化的冰盖引发了海平面的大幅上升。