地球的历史上曾经反复经历"冰河时期"——大片陆地被厚厚的冰川覆盖，海平面因此大幅下降。距今最近的一次冰河时期，大约在一万多年前结束。

Earth has repeatedly gone through "ice ages," with thick glaciers covering large areas of land and sea levels dropping sharply. The most recent ice age ended about ten thousand years ago.

科学家怎么知道几十万年前的气候是什么样？答案藏在"冰芯"里——从极地冰川深处钻取的冰柱，一层一层就像树的年轮，记录着当时的气温和空气成分。

How do scientists know what the climate was like hundreds of thousands of years ago? The answer lies in "ice cores" — cylinders drilled from deep polar glaciers, layered like tree rings, recording the temperature and air composition of the time.

• 🦁 赫拉克勒斯的十二项任务点击进入
• 🧊 气候与冰河期本期 · NOW
• 🖌️ 神笔马良点击进入
• 🧬 DNA与遗传的秘密点击进入
• 🐚 金螺王子桑通点击进入