如果你能用格陵蘭島和南極洲在過去30年里損失的冰做成一個正方體的冰塊，這個冰塊將高達(dá)2萬米。

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.

自上世紀(jì)90年代初以來，能夠監(jiān)測冰層高度和融化速度的衛(wèi)星一直在極地上空定期飛行。一組名為 “冰蓋質(zhì)量平衡相互比對試驗(IMBIE)” 的科學(xué)家匯集了這些衛(wèi)星記錄的數(shù)據(jù)，以了解格陵蘭島和南極洲應(yīng)對全球變暖的方式。

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.

在這段時間里，冰蓋損失了75600億噸的冰。損失的冰量足夠制造一個棱長為2萬米（12英里）的冰塊。融冰還導(dǎo)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.

冰蓋融化目前占全球海平面上升的25%，這個數(shù)字還在攀升。“冰蓋質(zhì)量平衡相互比對試驗” 研究小組說，冰蓋融化速度的加快意味著不久之后，格陵蘭島和南極洲融化成水的冰就會成為使全球海平面上升的主要因素。

詞匯表

elevation 高度
velocity 速率，速度
routinely 常規(guī)地，定期地
pulled together 收集了，匯集了
ice sheets 冰蓋
melt 融冰
dominant 主要的，主導(dǎo)的

閱讀理解：請在讀完上文后，回答下列問題。

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.