如果你能用格陵兰岛和南极洲在过去30年里损失的冰做成一个正方体的冰块，这个冰块将高达2万米。

Satellites able to monitor the elevation and velocity of ice have been flying routinely over the poles, now, since the early 90s. And a group of scientists, known as IMBIE (Ice Sheet Mass Balance Intercomparison Exercise), has pulled together their data to understand how Greenland and Antarctica are responding to a warming world.

自上世纪90年代初以来，能够监测冰层高度和融化速度的卫星一直在极地上空定期飞行。一组名为 “冰盖质量平衡相互比对试验(IMBIE)” 的科学家汇集了这些卫星记录的数据，以了解格陵兰岛和南极洲应对全球变暖的方式。

Combined, these ice sheets have lost 7,560 billion tonnes over the period. It's enough ice to make an ice cube 20 kilometres or 12 miles high. The melt also pushed up sea levels by 21 millimetres.

在这段时间里，冰盖损失了75600亿吨的冰。损失的冰量足够制造一个棱长为2万米（12英里）的冰块。融冰还导致海平面上升了21毫米。

The contribution from ice sheets to total sea level rise is now 25 percent and climbing. The acceleration in melting means it won't be long, the IMBIE team says, before ice lost from Greenland and Antarctica is the dominant factor pushing up the height of the world's oceans.

冰盖融化目前占全球海平面上升的25%，这个数字还在攀升。“冰盖质量平衡相互比对试验” 研究小组说，冰盖融化速度的加快意味着不久之后，格陵兰岛和南极洲融化成水的冰就会成为使全球海平面上升的主要因素。

词汇表

elevation 高度
velocity 速率，速度
routinely 常规地，定期地
pulled together 收集了，汇集了
ice sheets 冰盖
melt 融冰
dominant 主要的，主导的

阅读理解：请在读完上文后，回答下列问题。

1. When did the satellites mentioned in the article that monitor the elevation and velocity of ice start flying routinely over the poles?

2. Why has a group of scientists, known as IMBIE, pulled their data together?

3. How much ice had the ice sheets, combined, lost since the 1990s?

4. How much do the ice sheets melting contribute to rising sea levels?

答案

1. When did the satellites mentioned in the article that monitor the elevation and velocity of ice start flying routinely over the poles?

The satellites have been flying routinely over the poles since the early 90s.

2. Why has a group of scientists, known as IMBIE, pulled their data together?

They have pulled together their data to understand how Greenland and Antarctica are responding to a warming world.

3. How much ice had the ice sheets, combined, lost since the 1990s?

Combined, these ice sheets have lost 7,560 billion tonnes since the early 90s.

4. How much do the ice sheets melting contribute to rising sea levels?

The contribution from the melt of the ice sheets to total sea level rise is now 25 percent and climbing.