每日英語跟讀 Ep.857: One billion people will live in insufferable heat within 50 years地球暖化加劇 五十年內將有十億人口難以生活

The human cost of the climate crisis will hit harder, wider and sooner than previously believed, according to a new study that shows a billion people will either be displaced or forced to endure insufferable heat for every additional 1 degree Celsius rise in the global temperature.

研究指出，人類為氣候危機付出的代價將會比先前認為的更嚴重、更廣泛，而且更快發生。這份新研究顯示，每當全球溫度額外上升攝氏一度，就會有十億人口流離失所，或是被迫忍受難以承受的高溫。

In a worst-case scenario of accelerating emissions, areas currently home to a third of the world’s population will be as hot as the hottest parts of the Sahara within 50 years, the paper warns. Even in the most optimistic outlook, 1.2 billion people will fall outside the comfortable “climate niche” in which humans have thrived for at least 6,000 years.

該論文警告，在溫室氣體加速排放的最壞情況下，目前三分之一世界人口居住的地區，將會在五十年內變得跟撒哈拉沙漠最熱的區域一樣酷熱難耐。就算在最樂觀的觀點中，也會有十二億人口被排除在人類繁衍超過六千年的舒適「氣候棲位」範圍之外。

The authors of the study said they were “floored” and “blown away” by the findings because they had not expected our species to be so vulnerable. “The numbers are flabbergasting. I literally did a double take when I first saw them,” Tim Lenton, one of the study’s co-authors, said. “I’ve previously studied climate tipping points, which are usually considered apocalyptic. But this hit home harder. This puts the threat in very human terms.” Tim Lenton is the Director of Global Systems Institute of Exeter University.

作者群表示，他們對這份研究的發現感到大為震驚、目瞪口呆，因為他們並未預料到人類物種會是如此脆弱。研究共同執筆人提姆‧連頓表示：「這些數字讓人瞠目結舌。我第一次看到這些數字時，真的重新認真看了第二次。」連頓是英國艾克斯特大學全球系統研究所的主任，他指出：「我先前研究過氣候臨界點，這個門檻通常被認為是巨大災難性的。但是，這份結果擊中人類要害的力道更強，它把威脅用非常人類化的方式呈現出來。」

Instead of looking at climate change as a problem of physics or economics, the new paper, published in the Proceedings of the National Academy of Sciences, examines how it affects the human habitat. The vast majority of humanity has always lived in regions where the average annual temperatures are around 11 to 25 degrees Celsius, which is ideal for human health and food production. But this sweet spot is shifting and shrinking as a result of manmade global heating, which drops more people into what the authors describe as “near unlivable” extremes.

日前發表於《美國國家科學院院刊》的這份研究，並非以物理學或經濟學問題角度來看待氣候變遷，而是檢驗此變化會如何影響人類棲息地。長久以來，絕大多數人類都居住在年均溫介於攝氏十一度到二十五度之間的區域，這是維持人體健康和生產食物的理想範圍。然而，人造的全球熱化正在改變這個氣溫舒適帶，而且不斷縮小其範圍，使得更多人將生活在作者群描述為「幾乎無法居住」的極端氣溫中。

Humanity is particularly sensitive because we are concentrated on land — which is warming faster than the oceans — and because most future population growth will be in already hot regions of Africa and Asia. As a result of these demographic factors, the average human will experience a temperature increase of 7.5 degrees Celsius when global temperatures reach 3 degrees Celsius, which is forecast toward the end of this century.

人類對於氣溫特別敏感，是因為我們集中生活在陸地上，而陸地暖化速度又比海洋快。另一個原因在於，大部分的未來人口增長都位於非洲和亞洲等已經很熱的地區。由於這些人口學因素，當全球氣溫如專家預測在本世紀末上升攝氏三度時，人類平均感受到的氣溫會上升攝氏七點五度。

At that level, about 30 percent of the world’s population would live in extreme heat — defined as an average temperature of 29 degrees Celsius. These conditions are currently extremely rare outside the most scorched parts of the Sahara, but with global heating of 3 degrees Celsius, they are projected to envelop 1.2 billion people in India, 485 million in Nigeria and more than 100 million in each of Pakistan, Indonesia and Sudan.

到那個程度時，約有百分之三十的世界人口會生活在極端高溫中，此定義為均溫攝氏二十九度。目前，在撒哈拉沙漠最酷熱的區域之外，這種氣候條件極端少見。不過，當全球熱化達到攝氏三度時，極端高溫預期將壟罩印度十二億人口、奈及利亞四億八千五百萬人，以及巴基斯坦、印尼和蘇丹各地超過一億人口。

This would add enormously to migration pressures and pose challenges to food production systems. “I think it is fair to say that average temperatures over 29 degrees Celsius are unlivable. You’d have to move or adapt. But there are limits to adaptation. If you have enough money and energy, you can use air conditioning and fly in food and then you might be OK. But that is not the case for most people,” said one of the lead authors of the study, Marten Scheffer of Wageningen University.

極端高溫可能大幅增加移民壓力，並且對食物生產系統造成挑戰。該研究的主要作者之一、荷蘭瓦荷寧罕大學的馬汀‧斯海佛表示：「我認為，平均溫度超過攝氏二十九度是無法生活的，這個說法很合理。面對這樣的氣候，你必須移居或是去適應，但是適應有其限度。如果你有足夠的錢和能源，打開空調然後把食物用飛機運來，這樣也許還過得下去。但是對大部分的人來說，這並不可行。」

An ecologist by training, Scheffer said the study started as a thought-experiment. He had previously studied the climate distribution of rainforests and savanna and wondered what the result would be if he applied the same methodology to humans.

斯海佛是本科系出身的生態學家，他表示這份研究一開始是以「思想實驗」的形式出發。他先前曾經研究過氣候對雨林和莽原分布造成的影響，後來想到，如果把相同的研究方法套用在人類身上，結果會是什麼。

“We know that most creatures’ habitats are limited by temperature. For example, penguins are only found in cold water and corals only in warm water. But we did not expect humans to be so sensitive. We think of ourselves as very adaptable because we use clothes, heating and air conditioning. But, in fact, the vast majority of people live — and have always lived — inside a climate niche that is now moving as never before.” “We were blown away by the magnitude,” he said. “There will be more change in the next 50 years than in the past 6,000 years.”

斯海佛指出：「我們知道，大多數生物的棲地都受到溫度限制。比如說，企鵝只會出現在寒冷的海域，珊瑚只會生長在溫暖的海水中，但是卻沒想到人類會如此敏感。我們以為自己適應能力很強，因為人類會運用衣物、暖氣或空調。可是，事實上，絕大多數的人們、而且是一直以來，都居住在一個今日變化劇烈程度前所未見的氣候棲位中。」「這個巨大程度讓我們瞠目結舌。」他表示：「接下來五十年內發生的變化會比過去六千年來還要多。」

The authors said their findings should spur policymakers to accelerate emission cuts and work together to cope with migration because each degree of warming that can be avoided will save a billion people from falling out of humanity’s climate niche. “Clearly we will need a global approach to safeguard our children against the potentially enormous social tensions the projected change could invoke,” another of the authors, Xu Chi of Nanjing University, said.

作者群表示，這些發現應會鞭策決策者加快腳步訂立減少溫室氣體排放的相關政策，並且攜手合作處理移民問題。每一段暖化程度只要能夠避免發生，就可以拯救十億人，讓他們不會掉出人類的氣候棲位外。研究作者之一、中國南京大學的徐馳表示：「我們明顯需要採取全球性行動，來保衛我們的孩子，免於遭受預期氣候變化可能引發的潛在巨大社會緊張。」

Source article: https://www.taipeitimes.com/News/lang/archives/2020/05/10/2003736109