海平面上升速度破2800年以來紀錄
The oceans are rising faster than at any point in the last 28 centuries, and human emissions of greenhouse gases are primarily responsible, scientists reported Monday.
科學家本週一表示，海平面目前上升的速度比過去28個世紀中的任何時候都要快，而罪魁禍首就是人類排放的溫室氣體。
They added that the flooding that is starting to make life miserable in many coastal towns — like Miami Beach; Norfolk, Va.; and Charleston, S.C. — was largely a consequence of those emissions, and that it is likely to grow worse in coming years.
他們還表示，洪水正在讓很多沿海城鎮的生活苦不堪言——比如邁阿密海灘、弗吉尼亞州的諾福克，還有南卡羅來納州的查爾斯頓——這主要是人爲排放導致的，而且情況很可能在未來的年份裏惡化。
The scientists confirmed previous estimates, but with a larger data set, that if global emissions continue at a high rate over the next few decades, the ocean could rise as much as three or four feet by 2100, as ocean water expands and the great ice sheets in Greenland and Antarctica begin to collapse.
科學家們證實了先前的估算，但現在他們採用了一個更大的數據庫。這種估算認爲，如果全球溫室氣體排放的速率繼續在未來的幾十年中保持在較高水平，那麼隨着海水膨脹、格陵蘭島和南極洲的巨大冰蓋崩塌，海平面可能會到2100年上升多達3到4英尺。
Experts say the situation will grow far worse in the 22nd century and beyond, likely requiring the abandonment of many of the world’s coastal cities.
專家們稱，這種情況將自22世紀起嚴重惡化，世界各地的人們可能會被迫放棄很多沿海城市。
“I think we can definitely be confident that sea-level rise is going to continue to accelerate if there’s further warming, which inevitably there will be,” said Stefan Rahmstorf, a professor of ocean physics at the Potsdam Institute for Climate Impact Research in Germany and co-author of a paper released Monday by the Proceedings of the National Academy of Sciences.
“我認爲，我們絕對可以相信，如果出現進一步升溫，海平面上升的速率將會繼續加快，而進一步升溫在所難免，”德國波茨坦氣候影響研究所(Potsdam Institute for Climate Impact Research)的海洋物理學教授斯特凡·拉姆斯托夫(Stefan Rahmstorf)說。他是《美國國家科學院院刊》(The Proceedings of the National Academy of Sciences)本週刊登的一篇相關論文的合著者。
“Ice simply melts faster when the temperatures get higher,” Dr. Rahmstorf added. “That’s just basic physics.”
“隨着溫度的升高，冰融化的速度就會加快，”拉姆斯托夫博士說。“這是簡單的物理現象。”
In a report issued at the same time as the scientific paper, a climate research and communications organization in Princeton, N.J., Climate Central, used the new findings to calculate that roughly three-quarters of the tidal floods now occurring in towns along the American East Coast would not be happening in the absence of sea-level rise caused by human emissions.
這篇科學論文問世的同時，新澤西州普林斯頓的氣候研究與溝通機構氣候中心(Climate Central)也發表了一篇報告。文中使用這些新的結論來計算潮汐洪水，發現如果沒有人爲排放造成的海平面上升，美國東海岸城鎮目前的潮汐洪水中，大約有四分之三都不會發生。
The lead author of that report, Benjamin H. Strauss, said the same was likely to be true on a global scale, in any coastal community that has seen an increase of saltwater flooding in recent decades.
該報告的第一作者本傑明·H·施特勞斯(Benjamin H. Strauss)表示，在全球範圍內，情況很可能也是一樣的，很多海岸社區近幾十年經歷了潮汐洪水的增多。
Local factors do come into play, though: Communities on land that is sinking, as in the Chesapeake Bay region of the United States, are being hit especially hard by the rising sea level.
不過，其中也有局地因素在起作用：一些陸地區域正在下沉，比如在美國的切薩皮克灣地區，對於他們來說，海平面上升的打擊尤爲嚴重。
Tidal floods are occurring more frequently, and are becoming a strain in many towns by killing lawns and trees, polluting supplies of fresh water, blocking streets in the middle of sunny afternoons and sometimes stranding entire island communities for hours by covering the roads to the mainland.
潮汐洪水出現得更加頻繁，正在成爲很多城鎮的心腹之患。它們危害草坪和樹木，污染淡水供應，在陽光明媚的下午造成街道阻塞，海水漫過陸上道路，有時會讓整個島嶼社區癱瘓好幾個小時。
“I think we need a new way to think about most coastal flooding,” Dr. Strauss said in an interview. “It’s not the tide. It’s not the wind. It’s us. That’s true for most of the coastal floods we now experience.”
“我認爲，對於多數的沿海洪水，我們需要採取新的思考方式，”斯特勞斯博士在接受採訪時說。“原因不是海潮，也不是風，而是我們。對於目前的大多數沿海洪水來說，這就是事實。”
The new research was led by Robert E. Kopp, an earth scientist at Rutgers University who has won respect from his colleagues by bringing elaborate statistical techniques to bear on longstanding problems, like understanding the history of global sea level.
這項新的研究由羅格斯大學(Rutgers University)的地球科學家羅伯特·E·科普(Robert E. Kopp)牽頭進行。他將精密的統計學技術應用於一些長期存在的問題，比如怎樣瞭解全球海平面的歷史，贏得了同行的敬重。
Scientists already knew that the sea level rose drastically at the end of the last ice age, by almost 400 feet, causing shorelines to retreat by up to 100 miles in places. They also knew that the sea level had basically stabilized, like the rest of the climate, over the past several thousand years, the period when human civilization arose and spread across the earth.
科學家們已經知道，海平面在最後一個冰河時代結束時大幅上升了近400英尺（約合120米），造成有些地方的海岸線向陸地推進了至多100英里（約合160公里）。他們也知道，在過去幾千年中，海平面就像其他氣候元素一樣，基本趨於穩定。人類文明在這期間崛起，蔓延到地球各處。
There were small variations of climate and sea level over that period, and several recent papers have tried to clarify these. The new paper confirms a central finding of the earlier research, that the sharp increase of sea level in the 20th century was unprecedented over thousands of years, but does so with a larger data set that may add to the confidence scientists place in the results.
在此期間，氣候和海平面出現過一些微小的變化，最近刊出的幾篇論文試圖在這些方面做出清晰的解釋。這篇新的論文證實了早前研究的一個核心發現，即海平面在20世紀的急劇上升是幾千年來前所未有的，但是文中採用了一個更大的數據庫來證實這個發現，可能會增加科學家給這一結論的置信度。
The paper confirms that the ocean is exquisitely sensitive to small variations in the earth’s temperature — a portentous finding, given that human emissions are inducing a large temperature rise.
該論文確認，海洋對地球溫度的微小變化非常敏感——鑑於人類排放在導致溫度大幅上升，這個發現令人擔憂。
The researchers found that when the average global temperature fell by a third of a degree Fahrenheit in the Middle Ages, for instance, ice started to build up on land, and the volume of ocean water contracted, causing the average surface of the ocean to fall by about three inches over 400 years. When the climate warmed slightly, that trend reversed.
例如，研究人員得出結論，在中世紀，全球平均氣溫下降了0.2攝氏度，陸冰開始增加，海水總量減少，導致海平面在400年的時間裏平均下降了大約8釐米。當氣候略微轉暖時，這一趨勢便出現逆轉。
“Physics tells us that sea-level change and temperature change should go hand in hand,” Dr. Kopp said. “This new geological record confirms it.”
“物理學告訴我們，海平面變化和溫度變化是同進同退的，”科普博士說。“新的地質記錄證實了這個說法。”
In the 19th century, as the Industrial Revolution took hold, the oceans began to rise, and have gone up by about eight inches since 1880. That may sound small, but the increase has caused extensive erosion worldwide, and governments are spending billions of dollars to try to shore up beaches and other coastal defenses.
19世紀工業革命開始興起，海平面也開始上升，自1880年以來已經上升了約20釐米。這個幅度聽上去可能不大，但卻在世界各地引發了廣泛侵蝕，各國政府花費了數以億計的資金來加固海灘，強化其他沿海防禦措施。
Largely because of human emissions, global temperatures have jumped by about 1.8 degrees Fahrenheit since the 19th century. Land ice has started to melt all over the planet, and seawater is expanding as it absorbs heat. The seas are rising at what appears to be an accelerating pace, lately reaching a rate of about a foot per century.
自19世紀以來，全球氣溫大幅上升了約1攝氏度，這主要是人爲排放造成的。全球各地的陸冰開始融化，海水吸收熱量後膨脹。海平面日益上升，而且節奏似乎正在不斷加快，近期達到了每世紀約30釐米的速度。
One of the authors of the new paper, Dr. Rahmstorf, had previously published estimates suggesting the seas could rise as much as five or six feet by 2100. But with the improved calculations from the new paper, his latest upper estimate is three to four feet.
這篇新論文的作者之一拉姆斯托夫之前曾發表估算文章，其中表示，到2100年時，海平面會上漲至多五六英尺，但依據這篇新的論文，他估計上限會在三到四英尺之間。
That means Dr. Rahmstorf’s estimate is now more consistent with calculations issued in 2013 by the Intergovernmental Panel on Climate Change, a United Nations body that periodically reviews and summarizes climate research. The panel found that continued high emissions might produce a sea rise of 1.7 to 3.2 feet over the 21st century.
這意味着，拉姆斯托夫現在的估計和政府間氣候變化專門委員會（ Intergovernmental Panel on Climate Change，簡稱IPCC）2013年發佈的計算結果更趨一致。IPCC是聯合國機構，定期回顧和總結氣候研究。它發現，持續的高排放可能會導致海平面在21世紀上升53釐米到92釐米。
Dr. Rahmstorf said, however, that the rise would eventually exceed three feet — the only question is how long it will take. The recent climate agreement negotiated in Paris, if acted upon, will bring emissions down enough to slow the rate of sea-level rise in coming centuries, but scientists say the deal was not remotely ambitious enough to forestall a significant melting of the Antarctic and Greenland ice sheets.
不過，拉姆斯托夫稱，上升幅度最終會超過3英尺——唯一的問題是這需要多長的時間。如果按照最近在巴黎達成的氣候協議採取行動，把排放量降至足夠低的程度，那麼未來幾個世紀的海平面上升速率就會放緩。但科學家們表示，這份協議遠不足以阻止南極和格陵蘭冰蓋融化。
On a geologic time scale, the recent, human-induced planetary warming has been quite sudden, and the huge ice sheets have only just started to respond.
從地質時間的尺度來看，近來人類活動引起的地球變暖現象是相當突然的，巨大的冰蓋這纔剛剛開始有所反應。
The upper estimate of three to four feet of sea-level rise in the 21st century rules out any large contribution from Antarctica in the near term, but that finding is tentative, given that the ice covering the western part of that continent is already showing signs of instability. And recent studies suggest that the destruction of large parts of the Antarctic ice sheet may have become inevitable, even though that could take hundreds or thousands of years to play out.
在估計21世紀海平面的上升上限爲3到4英尺時，科學家排除了南極冰會在近期大幅融化的情景。但這只是個假設，覆蓋在南極大陸西部的冰已經顯示了不穩定跡象。近期的研究表明，南極大片地區的冰蓋遭到破壞或許已經成爲必然，儘管這一過程可能要延續數百或數千年的時間。
“Sea level is going to continue going up for many centuries,” Dr. Rahmstorf said.
“海平面將持續上升很多個世紀，”拉姆斯托夫說。
