原文标题：
Climate change
Mega-problems
What California’s storms reveal about the state’s climate future
气候变化
大问题
通过加州风暴看未来的气候
Climate change will intensify wet and dry periods in the Golden State
气候变化会加剧加州的旱涝灾害
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FEW THINGS are as welcome in California as rain. Bemoan an overcast sky and you will inevitably get some version of “We need the moisture” in reply.
加州的雨天很受欢迎。人们会在阴天发出叹息声，毫无疑问，你会听到各种版本“我们需要降水”的答案。
But when it began to pour on New Year’s Eve, kicking off more than a week of storms and interrupting a three-year period of extreme drought, this felt like a release of biblical proportions.
于是新年前夕开始下雨了，但开启了长达一周多的暴风雨天气，长达3年的极端干旱宣告结束，这像是《圣经》里的大场面。
The usually placid Los Angeles river raced through its concrete channel towards the Pacific.
往常平静的洛杉矶河现在迅速冲破混凝土水渠流向太平洋。
About 1,000 trees around Sacramento, the state capital, toppled over. As of January 11th, at least 19 people had been killed by winter storms. More than 30m Californians were living under flood warnings. And more wet weather was on the way.
州首府萨克拉门托约有1000棵树木倒伏。截至1月11日，至少有19人死于冬季风暴。3000万以上的加州人生活在洪水警报之中。更多的寒潮天气即将到来。
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The storms battering California are known as atmospheric rivers, which act as elongated corridors—hundreds to thousands of miles long—that carry water vapour through the atmosphere in a particular direction.
袭击加州的风暴被称为“大气层河流”，是长数百或数千英里的狭长路径，它携带水蒸气沿特定方向穿过大气层。
Atmospheric rivers usually make landfall on the west coasts of North America, Chile, South Africa, Europe and Australia, explains Daniel Swain, a climate scientist at the University of California, Los Angeles. At their mildest, the storms can just make for a rainy day.
加州大学洛杉矶分校的气候科学家丹尼尔·斯温解释说，大气层河流通常会在北美、智利、南非、欧洲和澳大利亚的西海岸登陆。在最温和的时候，只会下一天雨。
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At their most severe, they rival the hurricanes that clobber America’s east coast.
在最严重的时候，暴风雨可以与袭击美国东海岸的飓风媲美。
California usually gets its winter rain from atmospheric rivers. The difference this year is the high number of storms in quick succession.
加州的冬季降雨通常来自大气层河流。不同之处在于今年的风暴连续出现，应接不暇。
Once soil is saturated with moisture from one storm, it needs time to recover before it can absorb more rain.
经历一场暴风雨后，土壤被雨水浸透，它需要时间恢复，才能吸收更多的雨水。
But this time the storms came one after another. When rivers burst their banks, soil parched by years of drought could not soak up the excess water, leading to flooding.
但这一次暴风雨接踵而至。当河流决堤时，因久旱的土壤无法吸收多余的雨水，于是洪水泛滥了。
Tree roots made brittle by a lack of moisture could not withstand high winds and floodwaters. Areas burned by wildfires are susceptible to flash floods and mudslides.
树根由于缺乏水分而变得脆弱，因此无法抵御大风和洪水。野火烧过的区域也容易发生山洪和泥石流。
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It may seem confusing that California is underwater while the American south-west is in the grip of its driest 22-year period for at least 1,200 years.
美国西南地区陷入1200多年来最干旱的22年期时，加州却遭遇洪水，这似乎令人困惑。
But the Golden State’s severe drought and flooding are both consequences of the warming climate, as the relationship between wildfires and floods suggests.
但加州严重的干旱和洪水都是气候变暖的结果，就像野火和洪水之间的关系一样。
When temperatures rise, the atmosphere can hold more water vapour. A thirsty atmosphere will suck up more water from rivers, reservoirs and soil. This is called “evaporative demand”.
当气温升高时，大气中可以容纳更多的水蒸气。缺水的大气会从河流、水库和土壤中吸收更多的水。这就是“蒸发需求”。
When the atmosphere is fully saturated—think of a wet sponge—it will wring itself out, causing precipitation.
当大气完全饱和时--就像一块湿海绵--它会把自己拧干，形成降水。
A study published in 2018 in Nature Climate Change suggests that California will probably experience 25% to 100% more “whiplash” events, where the state passes quickly from an extremely dry summer to a very wet winter.
2018年发表在《自然气候变化》杂志上的一项研究表明，加州可能会增加25%-100%的天气“鞭打”事件，也就是从极度干燥的夏季迅速过渡到非常潮湿的冬季。
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While officials are focused on water scarcity, worries about a possible “megaflood” to rival the megadrought are spreading.
尽管官员们关注的是缺水问题，但越来越多人对可能出现的“特大洪水”（可与特大干旱匹敌）表示担忧。
In August Xingying Huang, of the National Centre for Atmospheric Research, and Mr Swain published a study suggesting that climate change has already doubled the risk of catastrophic flooding caused by a month-long series of strong atmospheric rivers.
8月，美国国家大气研究中心的黄兴英和斯温发表的一项研究表明，经历长达一个月之久的强大气层河流之后，气候变化已经使灾难性洪水风险增加了一倍。
Such a flood, they argue, would temporarily turn the Central Valley, the state’s agricultural powerhouse, into an inland sea, and inundate Los Angeles and Orange Counties, where 13m people live.
他们认为，灾难性洪水将使加州的农业重镇中央河谷变成临时内海，而且会淹没洛杉矶和橙县，这两地有1300万人口。
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These storms will pass, and summer may erase the gains made in reservoirs and groundwater basins. Attention will again turn to drought management.
暴风雨将会过去，夏季可能蒸发掉水库和地下水流域的存水。注意力将再次转向干旱管理。
But the increase in whiplash events reveals a need to adapt to different types of extreme weather, not just water scarcity.
但鞭打事件的增加表明加州需要适应不同类型的极端天气，不仅限于缺水问题。
Jeffrey Mount of the Public Policy Institute of California, a think-tank, argues that the Central Valley should be building levees farther back from the banks of the Sacramento river, to give the waters more room to roam.
智库加州公共政策研究所的杰弗里·芒特认为，中央河谷应该在距离萨克拉门托河岸更远的地方修建防洪堤，这样可以给洪水更多的上涨空间。
In addition to reducing flood risk, wider floodplains could help more water seep into underground aquifers, refilling groundwater basins that have been depleted by farmers.
除了减少洪水风险外，更宽的泛滥平原可以帮助更多的水渗入地下蓄水层，重新填充被农民耗尽的地下水盆地。
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Joan Didion, an American writer and a daughter of Sacramento, once described the uncertainty of living beside the valley’s rivers.
美国作家、萨克拉门托之女琼·迪迪恩曾描述过生活在山谷河流旁的不确定性。
“I think of the rivers rising,” she wrote, “of listening to the radio to hear at what height they would crest and wondering if and when and where the levees would go.”
她写道：“我想到了河水上涨的情景，想听收音机里的声音，想知道河水会涨到什么高度，想知道防洪堤会不会被冲垮，何时何地被冲垮。”
（恭喜读完，本篇英语词汇量711左右）
原文出自：2023年1月14日《The Economist》United States版块。
精读笔记来源于：自由英语之路
本文翻译整理: Irene
本文编辑校对: Irene
仅供个人英语学习交流使用。
【补充资料】（来自于网络）
加州之所以被称为"黄金之州"，因为黄金在该州的历史上扮演了重要的角色。居民还提到了金罂粟，一种当地的花，在全州都能找到大量的生长。加州太平洋沿岸的夕阳常常是美丽的黄色。加州立法机构在1968年将"金州"定为官方昵称。
大气层河流（atmospheric river）是位于对流层下层的，天气尺度的狭长水汽输送路径。大气层河流可见于热带至中纬度地区的洋面，可在全年出现，其出现时通常伴随有海洋性气旋、锋面活动和低空急流 。科学家认为最大的“大气层河流”的蓄水量相当于世界上最大河流亚马逊河。
蒸发需求(evaporative demand)是指在一定气象条件下从自由水面通过蒸发进入大气的最大水量，通常用蒸发掉的水层厚度的毫米数表示。蒸发量的空间变化，受气温、海陆、降水量等因素的影响。纬度越低，气温越高，蒸发能力越强，蒸发量也就越大；在温度相同条件下，海洋上的蒸发量高于内陆，并有自沿海向内陆显著减少的趋势；一般而言，降水量多的地方蒸发量也大，反之，蒸发量小。
天气鞭打事件定义为从一个持续的大尺度循环状态到另一个明显不同的循环状态的过渡。天气鞭打可能会从持续的干旱变成暴洪，或者从寒流变成异常高温。再或者，比如，可能从飓风季一个怪异的平静8月到历史性的飓风伊恩袭击了佛罗里达。
河流在洪水期溢出河床后堆积而成的平原。即河漫滩平原，在河流的中下段。泛滥平原发源于毗邻江、河道的地方。当河植的斜坡容纳不了河内的洪水径流而形成不能共存的关系时，便开始形成泛滥平原 floodplains。
地下水盆地（groundwater basin）是水文地质学，是地下水盆地是承压水盆地和潜水盆地的总称。
琼·狄迪恩（Joan Didion，1934年12月5日-2021年12月23日），美国随笔作家和小说家，她的文风以强烈的情感为特点，给人以一种落叶无根的感觉，表现出超然世外的态度。此外，她还把对社会的审视和个人忏悔融合进了作品中。2021年12月23日，琼·狄迪恩因帕金森并发症，在纽约曼哈顿家中去世，享年87岁。
【重点句子】（3 个）
At their most severe, they rival the hurricanes that clobber America’s east coast.
在最严重的时候，暴风雨可以与袭击美国东海岸的飓风媲美。
But the Golden State’s severe drought and flooding are both consequences of the warming climate, as the relationship between wildfires and floods suggests.
但加州严重的干旱和洪水都是气候变暖的结果，就像野火和洪水之间的关系一样。
But the increase in whiplash events reveals a need to adapt to different types of extreme weather, not just water scarcity.
但鞭打事件的增加表明加州需要适应不同类型的极端天气，不仅限于缺水问题。
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