愛語導(dǎo)讀:氣候變暖導(dǎo)致海平面上升，然而南極洲冰川消融占了多少比重？一起來看最新研究。

Global sea levels could rise by more than double the current best estimate, according to a new analysis of climate change in Antarctica.

據(jù)南極洲氣候變化最新研究顯示，全球海平面上升將是當前最保守估計量的2倍以上。

The modelling assessment says that Antarctic melting alone could contribute more than a metre to sea level by the end of this century.

模型評估顯示，到本世紀末，僅南極洲冰川融化就將使海平面上升1米以上。

By 2500, according to the study, the same source could cause levels across the world to rise by 13m.

該研究稱，到2500年，南極洲冰川融化將使全球海平面上升13米。

The authors say that rapid cuts in carbon emissions could limit this risk.

作者稱迅速削減碳排放可有效抑制這種風(fēng)險。

Competing ideas

爭論之聲

In 2013, the Intergovernmental Panel on Climate Change (IPCC) predicted that, without any restrictions on carbon emissions, the seas around the world likely rise by up to 98cm by 2100.

2013年，政府間氣候變化專門委員會（IPCC）預(yù)計，若碳排放不加限制，到2100年全球海平面將上升98cm。

However, the IPCC estimates contained a minimum contribution from Antarctica.

然而，IPCC的預(yù)估將南極洲融化的影響最小化了。

Other analyses since then have projected bigger increases, with a recent study suggesting that the oceans were rising faster than at any time in the past 2,800 years and by 2100 they could be up to 1.31m higher.

自那時起涌現(xiàn)了更多的相關(guān)分析。最近一項調(diào)查研究表明，海平面高度在過去2800年里以前所未有的速度增長，到2100年可能升高1.31米。

The exact level of Antarctica’s impact on these projections has been vigorously debated. Late last year, a research paper suggested that projections of a contribution of a metre or more were not plausible.

就南極洲對海平面升高究竟有多大影響的爭論一直很激烈。去年年底一份研究報告稱，預(yù)測南極洲對海平面的影響或超過1米的說法是不可信的。

But this new study argues that by 2100 the world could see 1.14m of sea-level rise from Antarctica alone.

但這項新研究稱，到2100年全球海平面僅因為南極洲影響就將升高1.14米。

Additions to the model

模型補充

The scientists say that their model is able to provide a more accurate prediction because it incorporates the impacts of some physical processes for the first time.

科學(xué)家說他們的模型能提供更加準確的預(yù)測，因為該模型首次包含了一些物理過程的影響。

While other models have focussed on the impact of warmer waters melting the ice shelves from below, this new study also includes the effect of surface melt-water and rain trickling down from above and fracturing supporting ice, hastening its slide to the sea.

其他模型關(guān)注的是溫度升高的海水自下而上融化冰架，而這項新研究同時考慮了表面融化的影響-水和雨自上而下滴落，以及支撐破碎的冰塊會滑入海中。

The model also calculates the impact of the disintegration of floating ice shelves. If this happens, it will reveal walls of ice so tall that they cannot support their own weight.

該模型還計算了漂浮冰架瓦解造成的影響。冰架如果瓦解，將露出冰墻，而冰墻高度太大，抵御不了自身重力影響。

The scientists involved expect that these extra factors will kick in over the coming decades, as warming from the atmosphere (not just from warmer waters below) becomes the dominant driver of ice loss.

相關(guān)科學(xué)家預(yù)計，接下來的幾十年中這些額外因素的影響將會加大，因為大氣溫度的升高（不僅僅從底部海水溫度升高）將會成為冰川融化的主導(dǎo)因素。

“One reason that other models didn’t include the atmospheric warming is because it hasn’t started to happen just yet,” said co-author Dr David Pollard from Penn State University, US.

“其他模型沒有考慮大氣變暖的原因之一是目前為止該情況還尚未發(fā)生?！惫餐髡哔e夕法尼亞州立大學(xué)大衛(wèi)波拉德博士說。

“In Antarctica, around the edges at sea level, it’s just beginning to get up to the melt point in summer.

“在南極洲，海平面在夏天剛好達到熔點?！?/p>

“With that warming, the flanks of Antarctica will start to melt drastically in about 50 to 100 years – and then it will start to kick in according to our model.”

“隨著溫度升高，在50至100年內(nèi)，南極洲側(cè)陸將開始大面積融化-根據(jù)我們的模型，那時它將占據(jù)主導(dǎo)地位?！?/p>

The authors believe that they have demonstrated the accuracy of the new model by correctly replicating sea-level rise in warm periods, millions of years into the past.

作者認為，通過正確模擬過去數(shù)百萬年間“暖期”海平面上升，他們已經(jīng)論證了新模型的準確性。

“Recently, we looked at the long-standing problem posed by geological evidence that suggests sea level rose dramatically in the past, possibly up to 10 to 20 metres around 3 million years ago, in the Pliocene,” said Dr Pollard.

“最近，我們研究了由地質(zhì)依據(jù)提出的存在已久的問題-海平面在過去曾大幅上升，比300萬年前“上新世”升高了10-20米?！辈ɡ虏┦空f。

“Existing models couldn’t simulate enough ice-sheet melting to explain that.”

“已有模型已無法模擬這么多的冰蓋融化來解釋這一點。”

Right questions’

正確的問題

If the world continues to emit “business as usual” levels of carbon dioxide over the coming decades, the scientists argue that sea-level rise will be double what has already been estimated for the coming 100 years.

在接下來的幾十年內(nèi)，如果全球持續(xù)“一如往?！钡嘏欧哦趸?，科學(xué)家預(yù)計海平面升高量將是原預(yù)計100年后升高量的2倍。

“If these processes do kick in and they end up being as important as we think that they could be, then they really do have a big impact,” said Prof Robert DeConto from the University of Massachusetts, Amherst.

“如果這些過程真的發(fā)生，并且最終發(fā)展成我們想象的程度，那它們的影響真的非常巨大?！卑λ固厥旭R薩諸塞大學(xué)的羅伯特迪康特教授說。

“West Antarctica is responding very soon in these simulations and that ends up having a big impact on North America in particular.”

“西南極洲最先印證了這些模擬，而這對北美洲有著巨大的影響?！?/p>

Other researchers have praised the development of the new model for including impacts such as surface melt water and ice-cliff collapse, but they are uncertain about the conclusions.

其他研究者贊揚了新模型的發(fā)展，因為它考慮了更多的因素，如表面融化雪水以及冰山崩塌，但他們對結(jié)論表示懷疑。

“I have no doubt that on a century to millennia timescale, warming will make these processes significant in Antarctica, as well as Greenland, and drive a very significant Antarctic contribution to sea-level rise,” commented Prof David Vaughan of the British Antarctic Survey.

“我從不懷疑本世紀直至新千年，氣候變暖將使南極洲這些進程加速，包括格陵蘭島，從而使得南極洲冰川融化對海平面上升的影響加劇?！庇蠘O調(diào)查局大衛(wèi)沃恩教授說。

“The big question for me is, how soon could this all begin, and could it be early enough to drive substantially higher sea levels by 2100? I’m not sure, but these guys are definitely asking the right questions.”

“對我而言最大的問題是，這一切最快什么時候開始，開始時間是否足夠早使得2100年海平面大幅上升？我不確定，但這些研究者們確實提出了正確的問題?！?/p>

The authors believe that there is “good news” in their report. If global emissions of carbon are curtailed significantly then the extra factors that substantially boost Antarctic melting will be avoided.

作者相信這份報道中還是有“好消息”的。如果全球碳排放大幅減小，這些造成南極洲消融的額外因素將得以避免。

Seas will continue to rise, but not at the runaway rates suggested by this paper, which has been published in the journal Nature.

海平面將持續(xù)上升，但不是以這篇發(fā)表在《自然》雜志中的論文闡述的那樣以失控的速度上升。

來源:BBC

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