科學家揭開格林蘭島維京人消失之謎
科學家表示，格林蘭島在12世紀時出現了氣溫驟降的現象，這也許可以解釋曾經居住在此的維京人爲何會銷聲匿跡。
Researchers reconstructed temperatures by examining lake sediment cores in west Greenland dating back 5,600 years.
研究者通過對於格林蘭島以西的湖泊的沉積物進行檢測，以追溯5600年前當地的氣候狀況。
Their findings indicated that earlier, pre-historic settlers also had to contend with vicious swings in climate on icy Greenland.
他們的發現表明，在早至史前時期，定居在此的人類不得不面對在冰天雪地的格林蘭島上變化無常的惡劣氣候的挑戰。
Average temperatures plunged 4C (7F) in just 80 years from about 1100.
研究發現，在1100年內的80年中，平均氣溫降低4攝氏度。
Such a shift is roughly the equivalent of the current average temperatures in Edinburgh tumbling to match those in Reykjavik, Iceland.
It would have been a huge setback to crop and livestock production.
這樣一種極端惡劣的氣候的變化相當於從愛丁堡、蘇格蘭目前的平均氣溫，驟降到冰島雷克雅維克的地區的氣溫，同時對於農業生產和牲畜的影響更是不言而喻。
Lead researcher Dr William D'Andrea, of Brown University, Rhode Island, said: 'Climate played (a) big role in Vikings' disappearance from Greenland.
來自美國羅德島布朗大學的威廉·迪安德瑞亞博士主導了這項研究，他說：“在維京人從格林蘭島上銷聲匿跡的這一過程中，氣候的變化扮演着重要的角色。”'There is a definite cooling trend in the region right before the Norse disappear.'
“在這些股挪威人消失以前，格林蘭島的氣溫的確變得更加寒冷了。”
Researchers have scant written or archaeological records to work out why Viking settlers abandoned colonies on the western side of the island in the mid-1300s and the eastern side in the early 1400s.
曾經定居在格陵蘭島的維京人在13世紀中葉以及14世紀初陸續開始從到西部和東路陸續前移離開此地，關於究竟是出於何種原因，目前已經很難找到相關的書面資料以及考古證據了。
Conflicts with indigenous Inuit, a search for better hunting grounds, economic stresses and natural swings in climate, perhaps caused by shifts in the sun's output or volcanic eruptions, could all be factors.
或許是與因紐特人發生了衝突，或希望尋找到更好的狩獵的環境，或是出於經濟壓力和自然氣候的波動，也許是因爲光照的條件或火山的爆發，這些都是有可能促成維京人從格林蘭島消息的因素。
Scientists have previously suspected that a cooling towards a Little Ice Age from the 1400s gradually shortened growing seasons and added to sea ice that hampered sailing links with Iceland or the Nordic nations.
此前，科學家曾懷疑，可能是由於14世紀時氣候正逐漸進入了一個小的冰川時期，四級組建縮短，而海洋開始結冰，從而對於連接冰島和古挪威的海上之路造成了阻礙。
The study, by scientists in the U.S. and Britain, added the previously unknown 12th century temperature plunge as a possible trigger for the colonies' demise.
這份有英國和美國科學家聯合參與的研究發現了之前未曾瞭解到因素，12世紀時的氣溫驟降或是誘發維京人從此地消失。
Vikings arrived in Greenland in the 980s, during a warm period like the present.
維京人在公園980年時遷徙到了格陵蘭島，當時的氣溫比較溫暖，就如同現在這樣。
Dr D'Andrea said: 'You have an interval when the summers are long and balmy and you build up the size of your farm, and then suddenly year after year, you go into this cooling trend, and the summers are getting shorter and colder and you can't make as much hay.'
迪安德瑞亞博士說：“在一開始的時候，夏季的時間較長，氣候溫和，這有利於發展和擴大農業，不過突然之間，夏季的時間越來越短，氣溫也越來越低，這將影響到對糧草的積累產生負面作用。”
The study, published in the U.S. journal Proceedings of the National Academy of Sciences, also traced even earlier swings in the climate to the rise and fall of pre-historic peoples on Greenland starting with the Saqqaq culture, which thrived from about 4,500 years ago to 2,800 years ago.
這項研究還追溯了早期的氣候變化對於生活在格林蘭島上史前人類的興衰所造成的影響，在4500到2800年前，這裏曾經出現過了Saqqaq文化。
Scientists fear that the 21st century warming is caused by climate change, stoked by a build-up of greenhouse gases from human acceleration of warming could cause a meltdown of the Greenland ice sheet, raising world sea levels.
科學家們擔心，由於生產生活所排放的溫室氣體所導致的全球變暖將導致21世紀的氣候變化，這有可能加速格林蘭島冰蓋的融化和崩潰，同時使得全球海平面升高。
