驅(qū)動沙塵暴的熱浪現(xiàn)在再次發(fā)生的可能性是以前的兩倍多

驅(qū)動沙塵暴的熱浪現(xiàn)在再次發(fā)生的可能性是以前的兩倍多

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.

它們被稱為“黑色暴風(fēng)雪”和“黑色滾柱”，即數(shù)千英尺高的滾滾沙塵，成為20世紀(jì)30年代襲擊美國的災(zāi)難性沙塵暴的不祥象征。這些令人窒息的風(fēng)暴橫掃美國大平原，使能見度降低到不到3英尺，并在到達(dá)東海岸時遮住了太陽，使自由女神像和美國國會大廈等著名地標(biāo)從視野中消失。

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，一位農(nóng)民寫道:“這是可怕的一周，有一天幾乎是完全的黑暗，還有一些星期，只有一部分陽光在黑暗中掙扎，發(fā)出一種奇怪的藍(lán)光。”在這樣的日子里，貯水池里的每一小波濁水都會發(fā)出藍(lán)光。當(dāng)我把一桶水舀到養(yǎng)雞場去的時候，它看上去幾乎就像覆蓋了一層油。”

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.

總而言之，沙塵暴和它所引發(fā)的黑色暴風(fēng)雪引發(fā)了美國1億多英畝的農(nóng)業(yè)中心地帶的干旱和侵蝕，從蒙大拿州一直延伸到德克薩斯州。雖然過度放牧和集約耕作為這場生態(tài)災(zāi)難奠定了基礎(chǔ)，但1934年和1936年創(chuàng)紀(jì)錄的熱浪——后者仍是有記錄以來最熱的——提供了關(guān)鍵的臨界點。

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.

根據(jù)剛剛發(fā)表在《自然氣候變化》雜志上的一項研究，在美國，由于氣候變化，像塵暴一樣的熱浪發(fā)生的可能性是每個世紀(jì)的兩倍多。

"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.

南昆士蘭大學(xué)研究員、該報告的第一作者蒂姆·考恩在接受《福布斯》采訪時表示:“1934年和1936年這些破紀(jì)錄的事件可能每100年發(fā)生一次，但由于目前的溫室氣體排放，這些事件減少到大約每30年或40年發(fā)生一次。”

Buying time with groundwater

利用地下水爭取時間

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.

如果自沙塵暴以來的農(nóng)業(yè)實踐已經(jīng)阻止了另一場災(zāi)難的發(fā)生，我們?yōu)槭裁匆獙ξ磥韼资耆绱藫?dān)憂呢?根據(jù)這項研究，農(nóng)民廣泛使用地下水灌溉有效地阻止了近代出現(xiàn)的黑色暴風(fēng)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.

考恩在接受哥倫比亞廣播公司采訪時表示：“我們從以前的研究中知道，地下水在美國被廣泛使用，灌溉和農(nóng)業(yè)集約化的增加導(dǎo)致了夏季最高溫度的降低。”

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.

由于地下水枯竭已經(jīng)發(fā)生，美國西部的廣大地區(qū)已經(jīng)被困在所謂的第一個人為造成的大洪水中，讓我們免受另一場沙塵暴襲擊的幸運之心可能只是時間問題。考恩補充說:“即使你現(xiàn)在有更好的種植方法，溫度的升高降低了這些益處，但是仍然會有負(fù)面影響。”

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.

研究小組的結(jié)論是，只有同時減少溫室氣體排放和地下水的使用，才能在未來阻止地平線上出現(xiàn)帶著高聳的塵埃云的黑色條紋。研究報告的撰寫者之一、愛丁堡大學(xué)氣候系統(tǒng)科學(xué)教授加比·海格爾在接受《福布斯》雜志采訪時警告說，1936年的熱浪可能會成為“新常態(tài)”。他說，今后幾十年的熱浪可能會超過以往任何一次。

"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.

她說:“預(yù)計本世紀(jì)美國的夏季極端天氣將會加劇，在不久的將來，上世紀(jì)30年代的高溫記錄可能會被打破。”