2023/11/08 研究發現，西南極冰川的快速融化「不可避免」，對全球海平面上升可能造成災難性影響

研究發現，西南極冰川的快速融化「不可避免」，對全球海平面上升可能造成災難性影響
Rapid melting in West Antarctica is ‘unavoidable,’ with potentially disastrous consequences for sea level rise, study finds
發表日期：2023-10-23
作者：Rachel Ramirez, CNN；翻譯：柯端榕
引用來源：https://edition.cnn.com/2023/10/23/world/west-antarctic-ice-melt-climate/index.html
 
『參考要點』：西南極洲的冰棚可能因全球暖化不可避免地快速融化，對全球海平面上升產生可怕的影響，引發沿海城市對未來海平面上升的擔憂。
『相關字彙』：potentially devastating（潛在毀滅性的）、sea level rise（海平面上升）、ocean warming（海洋暖化）、ice shelf melting（冰棚融化）、climate policies（氣候政策）
 
一項新研究指出，隨著人為全球暖化的加速，西南極的冰棚快速融化已是無法避免的，對世界各地的海平面上升可能造成毀滅性後果。即使全球達到限制全球暖化的目標，根據發表在《自然氣候變遷》期刊的新研究，西南極仍將經歷大規模的海洋升溫和冰棚融化。
Rapid melting of West Antarctica’s ice shelves may now be unavoidable as human-caused global warming accelerates, with potentially devastating implications for sea level rise around the world, new research has found. Even if the world meets ambitious targets to limit global heating, West Antarctica will experience substantial ocean warming and ice shelf melting, according to the new study published Monday in the journal Nature Climate Change.
冰棚是冰川末端伸出海洋的冰舌，有助於將冰固定在陸地上，減緩冰流進入海洋，提供重要的抵禦海平面上升的防禦措施。當冰棚融化時，將變薄並失去支撐能力。
Ice shelves are tongues of ice that jut out into the ocean at the end of glaciers. They act like buttresses, helping hold ice back on the land, slowing its flow into the sea and providing an important defense against sea level rise. As ice shelves melt, they thin and lose their buttressing ability.While there has been growing evidence ice loss in West Antarctica may be irreversible, there has been uncertainty about how much can be prevented through climate policies.
研究人員研究了「基底融化」，即溫暖的洋流從下方融化冰的情況。他們分析了不同氣候變遷情境下的海洋升溫速度和冰棚融化速度。他們發現，即使世界將升溫限制在攝氏1.5度，目前的情況並不符合這一目標，氣候變遷仍可能導致海洋升溫速度是歷史速度的三倍。
The researchers looked at “basal melting,” when warm ocean currents melt the ice from beneath. They analyzed the rate of ocean warming and ice shelf melting under different climate change scenarios. These ranged from the ambitious, where the world manages to limit global warming to 1.5 degrees Celsius above pre-industrial levels, to the worst-case, where humans burn large amounts of planet-heating fossil fuels. They found if the world limits temperature rise to 1.5 degrees Celsius, which it is not on track to do, climate change could still cause the ocean to warm at three times the historical rate.
英國南極調查局的海洋模擬專家凱特琳·諾頓（Kaitlin Naughten）表示：「我們可能已經失去了對21世紀西南極冰融化的控制。」西南極已經成為全球海平面上升的最大貢獻者，擁有足夠的冰，可以將海平面平均提高5.3公尺。它是南極斯維特冰川的所在地，也被稱為「末日冰川」，因為它的崩潰可能將海平面提高，迫使沿海社區和低地島國不是因應海平面上升，就是放棄這些地方。
Even significantly cutting planet-heating pollution now will have “limited power” to prevent warmer oceans from triggering the collapse of the West Antarctic ice sheet, the report found. “It appears that we may have lost control of the West Antarctic ice melting over the 21st century,” said Kaitlin Naughten, an ocean modeler with the British Antarctic Survey and lead author of the study. West Antarctica is already the continent’s largest contributor to global sea level rise and has enough ice to raise sea levels by an average of 5.3 meters, or more than 17 feet. It’s home to the Thwaites Glacier, also known as the “Doomsday glacier,” because its collapse could raise sea levels by several feet, forcing coastal communities and low-lying island nations to either build around sea level rise or abandon these places, Naughten said.
雖然該研究主要著重在冰棚融化，並未直接量化對海平面上升的影響，但諾頓表示，「我們有充分理由相信，隨著西南極加速將冰融入海洋，海平面上升將會增加。」
While the study focused on ice shelf melting and did not directly quantify the impacts on sea level rise, “we have every reason to expect that sea level rise would increase as a result, as West Antarctica speeds up this loss of ice into the ocean,” Naughten said.
美國科羅拉多大學博爾德分校的冰川學家泰德·斯坎博斯（Ted Scambos）告訴CNN，這些結果延續了現有研究，描繪了正發生在地球大陸最南端令人擔憂的景象。令人沮喪的是，尤其是在未來一個世紀，海平面上升的趨勢不可避免。今天活著的人們將在全球沿海城市看到海平面上升速度的顯著增加，唯一停止冰快速融化的方法不僅是減少全球暖化的污染，還要「清除已經積累的污染」，這將是「一個真正的挑戰」。
Ted Scambos, a glaciologist at the University of Colorado Boulder who was not involved with the study, said the findings are “sobering.” They build on existing research that paints an alarming picture of what’s happening to the planet’s southernmost continent, he told CNN.“The thing that’s depressing is the committed nature of sea level rise, particularly for the next century,” Scambos told CNN. “People who are alive today are going to see a significant increase in the rate of sea level rise in all the coastal cities around the world.”The only way to really stop the rapid ice melting, Scambos said, would be not just to cut levels of planet-heating pollution but also to “remove some that has already built up.” This will be “a real challenge,” he said.
英國國家海洋學中心的高級研究科學家蒂亞戈·塞加比納茲·多托（Tiago Segabinazzi Dotto）表示，由於該研究基於單一模型，應該「謹慎對待」。該研究的結論與該地區的先前研究一致，這給了「讓政策制定者考慮這項研究的信心」。
Some scientists sounded a note of caution about the study. Tiago Segabinazzi Dotto, senior research scientist at the National Oceanography Centre in the UK, said it should be “treated carefully” as it is based on a single model.However, its conclusions do agree with previous research in the region, he told the Science Media Center, giving “confidence that this study needs to be taken in consideration for policymakers.”
預測未來西南極融化速度非常複雜，無法考慮每一種可能的未來結果，但報告的作者表示，從不同情境的範圍來看，他們確信冰棚融化現在已經不可避免。西南極冰棚的融化是氣候變遷的一個影響，「我們可能只能適應，這很可能意味著我們無法避免一定程度的海平面上升。」
Naughten and her colleagues acknowledged their study has limits — predicting future rates of melting in West Antarctica is very complex and it’s impossible to account for every possible future outcome. But, looking at the range of scenarios, the report authors said they were confident the melting of ice shelves is now unavoidable. West Antarctic ice shelf melting is one impact of climate change “we are probably just going to have to adapt to and that very likely means some amount of sea level rise we cannot avoid,” Naughten said.
儘管前景令人憂慮，人類不能放棄減少化石燃料排放，在其他南極地區和世界其他地方，仍然可以避免災難性影響。
But although the outlook is dire, humanity cannot give up on slashing fossil fuel emissions, Naughten said. Devastating impacts can still be avoided in other parts of Antarctica and the rest of the world, she noted.