Sea ice is not just crucial to the lives of those creatures that live around the poles.
海冰不僅對那些生活在兩極地區的生物至關重要。
be crucial to 對...至關重要
creature 生物
pole 兩極
It plays a vital role in determining the climate of the whole planet.
而且在全球氣候方面，也起著決定性作用。
play a ...role in 在..方面有作用
vital 至關重要的
determine 決定
planet 星球
A white surface keeps the earth cool by reflecting most of the sun's energy back into space.
雪白的冰面反射了大部分太陽光能，從而實現為地球降溫的效果。
keep sth.+adj. 使某物保持..
reflect 反射
energy 能量
A dark surface does the opposite, absorbing over 90 percent of the sun's energy and so warming the earth.
深色的海面則起到相反作用，會吸收太陽光能的百分之九十，因此會使地球變暖
opposite 相反
absorb 吸收
warm 使變暖
As the sea ice shrinks, we're starting to lose one of our planet's protective white shields.
隨著海冰的消融，我們即將失去這面保護地球的白色盾牌。
shrink 收縮；畏縮
protective 防護的；保護的
shield 盾牌
For thousands of years, there's been a balance in the advance and retreat of the sea ice, but that is no longer the case.
數千年以來，海冰一直在增長與消退之間保持平衡，但如今平衡被打破了。
balance 平衡
advance 前進；發展
retreat 撤退；消退
no longer 不再