驱动沙尘暴的热浪现在再次发生的可能性是以前的两倍多

驱动沙尘暴的热浪现在再次发生的可能性是以前的两倍多

They were called "black blizzards" and "black rollers," towering billows of dust rising thousands of feet high that became ominous symbols of the catastrophic Dust Bowl that hit the United States during the 1930s. Sweeping across the Great Plains, these choking storms reduced visibility to less than three feet and, upon reaching the East Coast, blotted out the sun and erased from view prominent landmarks such as the Statue of Liberty and the U.S. Capitol Building.

它们被称为“黑色暴风雪”和“黑色滚柱”，即数千英尺高的滚滚沙尘，成为20世纪30年代袭击美国的灾难性沙尘暴的不祥象征。这些令人窒息的风暴横扫美国大平原，使能见度降低到不到3英尺，并在到达东海岸时遮住了太阳，使自由女神像和美国国会大厦等著名地标从视野中消失。

A dust storm approaches Stratford, Texas, in 1935. (Photo: NOAA George E. Marsh Album [public domain]/Wikimedia Commons)

"It has been a terrible week, with one day of almost complete obscurity, and others when only a part of the sun's rays struggled through the gloom with a strange bluish luminance," wrote one farmer in 1936. "On such days each little wave of the troubled water in the stock tank glitters with a blue phosphorescent light. When I dip out a pail of water to carry to the hen-house, it looks almost as if it were covered with a film of oil."

1936年，一位农民写道:“这是可怕的一周，有一天几乎是完全的黑暗，还有一些星期，只有一部分阳光在黑暗中挣扎，发出一种奇怪的蓝光。”在这样的日子里，贮水池里的每一小波浊水都会发出蓝光。当我把一桶水舀到养鸡场去的时候，它看上去几乎就像覆盖了一层油。”

All told, the Dust Bowl and the black blizzards it spawned triggered drought and erosion across more than 100 million acres of America's agricultural heartland, stretching from Montana to Texas. While overgrazing and intensive farming practices laid the foundation for the ecological disaster, record-setting heatwaves in 1934 and 1936 — with the latter still the hottest ever recorded — provided the critical tipping point.

总而言之，沙尘暴和它所引发的黑色暴风雪引发了美国1亿多英亩的农业中心地带的干旱和侵蚀，从蒙大拿州一直延伸到德克萨斯州。虽然过度放牧和集约耕作为这场生态灾难奠定了基础，但1934年和1936年创纪录的热浪——后者仍是有记录以来最热的——提供了关键的临界点。

According to study just published in the journal Nature Climate Change, a Dust Bowl-like heat wave is now more than twice as likely to happen in the U.S. each century due to climate change.

根据刚刚发表在《自然气候变化》杂志上的一项研究，在美国，由于气候变化，像尘暴一样的热浪发生的可能性是每个世纪的两倍多。

"These record-breaking events in 1934 and 1936 occurred perhaps once every hundred years, but with present day greenhouse gases they reduced to about one in every 30 or 40 years," Tim Cowan, a research fellow at the University of Southern Queensland and the report's lead author, told Forbes.

南昆士兰大学研究员、该报告的第一作者蒂姆·考恩在接受《福布斯》采访时表示:“1934年和1936年这些破纪录的事件可能每100年发生一次，但由于目前的温室气体排放，这些事件减少到大约每30年或40年发生一次。”

Buying time with groundwater

利用地下水争取时间

Heavy black clouds of dust rise over the Texas Panhandle, Texas, c. 1936 (Photo: Arthur Rothstein [public domain]/Wikimedia Commons)

If farming practices since the Dust Bowl have prevented another from happening, why should we be so concerned about the coming decades? According to the study, widespread use of groundwater irrigation by farmers has effectively kept a lid on black blizzards from appearing in modern times.

如果自沙尘暴以来的农业实践已经阻止了另一场灾难的发生，我们为什么要对未来几十年如此担忧呢?根据这项研究，农民广泛使用地下水灌溉有效地阻止了近代出现的黑色暴风雪。

"Groundwater is used quite extensively across the U.S., and we know, from previous research, that increased irrigation and agricultural intensification has led to cooler summer maximum temperatures," Cowan told CBS News.

考恩在接受哥伦比亚广播公司采访时表示：“我们从以前的研究中知道，地下水在美国被广泛使用，灌溉和农业集约化的增加导致了夏季最高温度的降低。”

With groundwater depletion already occurring and vast regions of the western U.S. already locked in what's described as the first human-caused megadrought, it's likely only a matter of time before the luck that has kept us sheltered from another Dust Bowl runs out. "Even though you have better practices in cropping now, the rises in temperature reduce those benefits, so there would still be a negative impact," Cowan added.

由于地下水枯竭已经发生，美国西部的广大地区已经被困在所谓的第一个人为造成的大洪水中，让我们免受另一场沙尘暴袭击的幸运之心可能只是时间问题。考恩补充说:“即使你现在有更好的种植方法，温度的升高降低了这些益处，但是仍然会有负面影响。”

The research team concludes that only reductions in both greenhouse gas emissions and groundwater use will help stem future instances of horizons streaked black with towering dust clouds. Warning that such events as the 1936 heat wave could become "the new normal," study co-author Gabi Hegerl, professor of climate system science at the University of Edinburgh, told Forbes that the next decades will likely eclipse anything since.

研究小组的结论是，只有同时减少温室气体排放和地下水的使用，才能在未来阻止地平线上出现带着高耸的尘埃云的黑色条纹。研究报告的撰写者之一、爱丁堡大学气候系统科学教授加比·海格尔在接受《福布斯》杂志采访时警告说，1936年的热浪可能会成为“新常态”。他说，今后几十年的热浪可能会超过以往任何一次。

"With summer heat extremes expected to intensify over the US throughout this century, it is likely that the 1930s records will be broken in the near-future," she said.

她说:“预计本世纪美国的夏季极端天气将会加剧，在不久的将来，上世纪30年代的高温记录可能会被打破。”