到2070年，世界上1/3的人口將會籠罩在撒哈拉般的熱浪中大綱

A Third of the World's Population Could Be Blanketed in Sahara-Like Heat by 2070
到2070年，世界上三分之一的人口將會籠罩在撒哈拉般的熱浪中
Brain geniuses like Elon Musk may want to colonize Mars, which sure. But for simpletons like me, keeping Earth Mostly habitable seems like a better use of time and resources.
像埃隆·馬斯克這樣的大腦天才可能想要征服火星，好吧，這是肯定的。但是對於像我這樣的傻瓜來說，讓地球的大部分都適合人類居住似乎是對時間和資源的更好利用。
If carbon emissions are allowed to continue unchecked, though, that may be a tough proposition. According to a new study, extreme heat now only found in parts of the Sahara could spread to nearly 20 percent of the globe (and nearly a third of humanity) if carbon emissions aren’t curtailed. The paper, published on Monday in the Proceedings of the National Academy of Sciences, makes a pretty compelling case to cut carbon emissions and not fry the world.
然而，如果碳排放繼續不受限制，這可能是一個艱難的事情。根據一項新研究，如果不減少碳排放，目前只在撒哈拉沙漠部分地區發現的極端高溫可能會蔓延到全球近20%的地區（波及近三分之一的人類）。這篇週一發表在《美國國家科學院院刊》上的論文爲減少碳排放，不讓全球變暖提出了一個相當有說服力的理由。
The authors of the new paper use a host of historical data going back 6,000 years ago to uncover just what conditions make humans tick. It turns out people can make do with all levels of rainfall, with humans living in all but the very driest places on Earth. Civilization has also adapted to all types of soil fertility. The biggest limiting factor in terms of human habitation is how hot it gets.
這篇新論文的作者使用了近6000年的大量歷史數據來揭示人類生存的條件。事實證明，除了在地球上最乾旱的地方，人類都可以設法應對各種程度的降雨。文明也適應了各種類型的土壤肥力。人類居住的最大限制因素是溫度會有多高。
The results of the study show people thrive in a narrow temperature band, where the average annual temperature spans 11 to 15 degrees Celsius or roughly the 50s if you’re into Fahrenheit. It’s in that belt where many staple crops grow best and livestock can be highly productive, and it’s why the authors define it as the “human climate niche.” That’s not say there aren’t other confounding factors for human thriving, but temperature is one of the key elements linked with well-being.
研究結果顯示，人們只能在一個狹窄的溫度範圍內生活得很好，這一範圍是年平均溫度在11到15攝氏度之間，如果你喜歡華氏溫度，那大概就在50多華氏度左右。正是在這一範圍內，許多主食作物長勢最好，牲畜產量也很高，這也就是作者將其定義爲“人類氣候生態位”的原因。這並不是說沒有其他影響人類健康的因素，但溫度是影響健康的關鍵因素之一。
Unfortunately for us, there’s a shock on the way if climate change continues unchecked. We’re already seeing the toll rising heat is taking on people around the world, from heat wave-related deaths to billions of hours in lost productivity because it was simply too hot to be outside. Still, humans have made it work in many hot places, from Phoenix to New Delhi to Dubai. But eventually, climate change could overwhelm us.
對我們來說不幸的是，如果氣候變化繼續不受控制，我們就會面臨衝擊。我們已經看到了不斷上升的高溫對世界各地的人們造成的影響，從熱浪導致的死亡，到因天氣太熱而無法外出導致的數十億小時的生產力損失。儘管如此，從鳳凰城到新德里再到迪拜，人類已經在許多炎熱的地方想辦法克服高溫。但最終，氣候變化會壓倒我們。
The study uses RCP8.5, a scenario where carbon emissions rise on an extreme level, to model what the end of the century would look like for our little human climate niche. The results show it would contract substantially. The Sahara is one of the only places on Earth where the annual average temperature cranks above 29 degrees Celsius (84 degrees Fahrenheit) and where the human climate niche basically ends. The areas with that much heat only cover 0.8 percent of the world’s land. But by 2070, that type of heat would become commonplace over nearly 20 percent of land on Earth. That area is home to up to 3 billion people who, if they don’t migrate, will be living in conditions humans have never been able to tolerate for year-round existence.
該研究使用了RCP8.5，即碳排放達到極端水平的情景，來模擬本世紀末人類氣候生態位的狀況。結果表明，它將大幅縮小。撒哈拉沙漠是地球上僅有的年平均氣溫超過29攝氏度（84華氏度）的地方之一，也是人類氣候生態位基本結束的地方。擁有如此高熱量的地區僅佔世界陸地面積的0.8%。但到2070年，這種類型的高溫將在地球近20%的土地上變得司空見慣。這麼大的地區是多達30億人的家園，如果他們不遷移，將會生活在人類永遠無法忍受的環境中。
What’s more, this spike in temperature over the intervening 50 years will be more dramatic than anything experienced in at least 6,000 years. You know, the period where human civilization really hit its groove.
更重要的是，這50年間的溫度峯值將比至少6000年來的任何一次都要劇烈。你要知道，這段時間也是人類文明真正達到巔峯的時期。
The results are truly shocking in map form. Nearly all of Brazil will become essentially uninhabitable, as will huge chunks of the Middle East and India, showing the poorest areas will be hit the hardest. But the impacts aren’t limited to developing countries; the U.S. South, parts of Australia, and Mediterranean Europe will also see temperatures beyond the niche. The flip, though, that North America and Europe will also make habitability gains. When scientists found last year that we were all going to want to move to Siberia by the end of the century, they weren’t kidding.
以地圖形式呈現的結果確實令人震驚。幾乎整個巴西都將變得無法居住，中東和印度的大部分地區也將如此，這表明最貧困的地區將受到最嚴重的打擊。但影響並不僅限於發展中國家；美國南部、澳大利亞部分地區和歐洲地中海地區的氣溫也將超過生態位的範圍。不過，反過來說，北美和歐洲的居住性會有所提高。當科學家們去年發現我們都會在本世紀末搬到西伯利亞時，他們並不是在開玩笑。
That’s what’s most alarming about the results. They show that, absent curbing emissions, there will almost certainly be mass migrations out of the hot zones. It won’t all happen in 2070 like a switch flipped. Rather, some areas will pass the climate niche threshold first, potentially triggering waves of migration. The results show that, first and foremost, we need to start cutting emissions now. But just as important is the need to prepare for climate-induced migration in the future. And not in the ecofascist kind of way.
這就是最令人擔憂的結果。它們表明，如果不遏制排放，幾乎可以肯定會有大量人口遷出高溫地區。這一切並不會像開關一樣在2070年開啓。相反，一些地區將首先突破氣候生態位閾值，可能引發移民潮。研究結果表明，首先，我們需要現在就開始減少碳排放。但同樣重要的是，需要爲未來因氣候導致的移民做好準備，而不是用生態法西斯的方式應對它。