研究人员估算出冰河时期的地球温度

Researchers Estimate Earth’s Temperatures During Ice Age
研究人员估算出冰河时期的地球温度
Scientists say they have calculated temperatures on Earth’s surface during the last Ice Age.
科学家们称，他们已经计算出了最近一次冰河时期地球表面的温度。
The researchers made their calculations with the help of fossilized remains of ocean plankton and models of climates tens of thousands of years ago in different parts of the world.
研究人员借助海洋浮游生物化石和世界各地数万年前的气候模型对此进行了计算。
The researchers reported their findings in the British scientific publication Nature.
研究人员在英国科学出版物《自然》杂志上发布了这一研究发现。
The most recent Ice Age lasted from about 115,000 to 11,000 years ago. During this time, huge sheets of ice covered much of North America, South America, Europe and Asia.
最近一次冰河期大约是11.5万年前到1.1万年前这段时期。在此期间，北美洲、南美洲、欧洲和亚洲的大部分地区都被巨大的冰层覆盖。
The researchers said the average temperature worldwide during the height of this period, known as the Last Glacial Maximum, was about 7.8 degrees Celsius. That average Ice Age temperature was about 6 degrees Celsius colder than the average today. The average world temperature during the 20th century was 14 Celsius, the scientists noted.
研究人员表示，在这段被称为最后一次冰期最高点的时期——又称“末次冰盛期”，全球平均气温约为7.8摄氏度。冰河时期的平均温度比今时今日的平均温度约低6摄氏度。科学家们指出，20世纪世界平均气温为14摄氏度。
Some areas were much colder than the average, they found. Extreme northern and southern regions cooled far more than other areas, with the Arctic region 14 degrees Celsius colder than the world average.
他们发现，有些地区的气温要比平均温度低得多。北极和南极地区的低温程度远远超过其他地区，比如北极地区比世界平均气温水平低14摄氏度。
“We have a lot of data about this time period because it has been studied for so long,” said Jessica Tierney in a statement. “But one question science has long wanted answers to is simple: How cold was the Ice Age?”
杰西卡·蒂尔尼在一份声明中称：“因为对此时期进行的研究已经进行了很长时间，因此我们有很多关于这一时期的数据。但科学界长期以来想要回答的一个问题其实很简单，那就是——冰河时期到底有多冷?”
Tierney helped lead the study. She is a paleoclimatologist with the University of Arizona.
蒂尔尼是亚利桑那大学的古气候学家，也是她协助领导了这项研究。
Tierney said that looking at information from past climates is the only way to find out what truly happens when the Earth experiences long cold or warm periods. “So, by studying them, we can better constrain what to expect in the future,” she said.
蒂尔尼表示，研究过去的气候信息是发现地球在经历漫长冷/暖期时真正状况的唯一方法。她说：“因此通过研究它们，我们可以更好地限定对未来的预期。”
During the Ice Age, our planet was home to large mammals such as mammoths, mastodons, woolly rhinoceros and saber-toothed cats. These animals were able to survive in a cold climate.
在冰河时期，我们的星球是诸如猛犸象、乳齿象、毛犀和剑齿虎等大型哺乳动物的家园。这些动物能够在寒冷的气候中生存。
Early humans entered North America for the first time during the Ice Age, crossing a land bridge that once connected Siberia to Alaska with sea levels much lower than they are today.
早期人类在冰河时期穿过一座曾经连接西伯利亚和阿拉斯加的陆地桥第一次进入北美，当时那里的海平面比现在低得多。
“What is interesting is that Alaska was not entirely covered with ice,” Tierney said. “There was an ice-free corridor that allowed humans to travel across the Bering Strait, into Alaska. Central Alaska was actually not that much colder than today, so for Ice Age humans it might have been a relatively nice place to settle.”
蒂尔尼称：“有趣的是阿拉斯加并没有完全被冰覆盖。当时那里有一条无冰走廊，允许人类穿越白令海峡进入阿拉斯加。阿拉斯加中部实际上并没有比今天冷多少，所以对于冰河时代的人类来说，这里可能是一个相对不错的定居地。”
Human hunting is believed to have been partly responsible for many Earth species disappearing at the end of the Ice Age.
冰河时代末期许多地球物种消失部分原因被归咎于人类的狩猎活动。
Atmospheric carbon dioxide levels during the Ice Age were about 180 parts per million, which is very low, the researchers said. Before the Industrial Revolution of the 1800s, levels rose to about 280 parts per million. Today they are about 415 parts per million.
研究人员表示，冰河时期大气中的二氧化碳含量约为百万分之180——含量非常低。在19世纪工业革命前，二氧化碳含量上升到百万分之280左右。而今天，它们占比大约是百万分之415。
The researchers announced plans to use their temperature calculation methods to recreate warm periods in Earth’s history.
研究人员还宣布了新计划，称将使用此类温度计算方法来重现地球历史上的暖期。
“If we can reconstruct past warm climates, then we can start to answer important questions about how the Earth reacts to really high carbon dioxide levels…” Tierney said. This can help scientists expand their understanding of what future climate change might bring.
蒂尔尼称：“如果我们能够重建过去的温暖气候，那么我们就可以回答一些重要的问题，即地球对非常高浓度的二氧化碳将作何反应……”。这有助于科学家们拓展对未来气候变化的潜在影响的理解。
I’m Bryan Lynn.
布莱恩·林恩报道。