原文標題：
Climate change
Mega-problems
What California』s storms reveal about the state』s climate future
氣候變化
大問題
通過加州風暴看未來的氣候
Climate change will intensify wet and dry periods in the Golden State
氣候變化會加劇加州的旱澇災害
[Paragraph 1]
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.
加州的雨天很受歡迎。人們會在陰天發出嘆息聲，毫無疑問，你會聽到各種版本「我們需要降水」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.
於是新年前夕開始下雨了，但開啟了長達一周多的暴風雨天氣，長達3年的極端乾旱宣告結束，這像是《聖經》里的大場面。
The usually placid Los Angeles river raced through its concrete channel towards the Pacific.
往常平靜的洛杉磯河現在迅速衝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.
州首府薩克拉門托約有1000棵樹木倒伏。截至1月11日，至少有19人死於冬季風暴。3000萬以上的加州人生活在洪水警報之中。更多的寒潮天氣即將到來。
[Paragraph 2]
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.
襲擊加州的風暴被稱為「大氣層河流」，是長數百或數千英里的狹長路徑，它攜帶水蒸氣沿特定方向穿過大氣層。
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.
加州大學洛杉磯分校的氣候科學家丹尼爾·斯溫解釋說，大氣層河流通常會在北美、智利、南非、歐洲和澳大利亞的西海岸登陸。在最溫和的時候，只會下一天雨。
[Paragraph 3]
At their most severe, they rival the hurricanes that clobber America』s east coast.
在最嚴重的時候，暴風雨可以與襲擊美國東海岸的颶風媲美。
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來自大氣層河流。不同之處在於今年的風暴連續出現，應接不暇。
Once soil is saturated with moisture from one storm, it needs time to recover before it can absorb more rain.
經歷一場暴風雨後，土壤被雨水浸透，它需要時間恢復，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.
但這一次暴風雨接踵而至。當河流決堤時，因久旱的土壤無法吸收多餘的雨水，於是洪水泛濫了。
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.
樹根由於缺乏水分而變得脆弱，因此無法抵禦大風和洪水。野火燒過的區域也容易發生山洪和泥石流。
[Paragraph 4]
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.
美國西南地區陷入1200多年來最乾旱的22年期時，加州卻遭遇洪水，這似乎令人困惑。
But the Golden State』s severe drought and flooding are both consequences of the warming climate, as the relationship between wildfires and floods suggests.
但加州嚴重的乾旱和洪水都是氣候變暖的結果，就像野火和洪水之間的關係一樣。
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」.
當氣溫升高時，大氣中可以容納更多的水蒸氣。缺水的大氣會從河流、水庫和土壤中吸收更多的水。這就是「蒸發需求」。
When the atmosphere is fully saturated—think of a wet sponge—it will wring itself out, causing precipitation.
當大氣完全飽和時--就像一塊濕海綿--它會把自己擰乾，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年發表在《自然氣候變化》雜誌上的一項研究表明，加州可能會增加25%-100%的天氣「鞭打」事件，也就是從極度乾燥的夏季迅速過渡到非常潮濕的冬季。
[Paragraph 5]
While officials are focused on water scarcity, worries about a possible 「megaflood」 to rival the megadrought are spreading.
儘管官員們關注的是缺水問題，但越來越多人對可能出現的「特大洪水」（可與特大幹旱匹敵）表示擔憂。
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，美國國家大氣研究中心的黃興英和斯溫發表的一項研究表明，經歷長達一個月之久的強大氣層河流之後，氣候變化已經使災難性洪水風險增加了一倍。
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.
他們認為，災難性洪水將使加州的農業重鎮中央河谷變成臨時內海，而且會淹沒洛杉磯和橙縣，這兩地有1300萬人口。
[Paragraph 6]
These storms will pass, and summer may erase the gains made in reservoirs and groundwater basins. Attention will again turn to drought management.
暴風雨將會過去，夏季可能蒸發掉水庫和地下水流域的存水。注意力將再次轉向乾旱管理。
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適應不同類型的極端天氣，不僅限於缺水問題。
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.
智庫加州公共政策研究所的傑弗里·芒特認為，中央河谷應該在距離薩克拉門托河岸更遠的地方修建防洪堤，這樣可以給洪水更多的上漲空間。
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.
除了減少洪水風險外，更寬的泛濫平原可以幫助更多的水滲入地下蓄水層，重新填充被農民耗盡的地下水盆地。
[Paragraph 7]
Joan Didion, an American writer and a daughter of Sacramento, once described the uncertainty of living beside the valley』s rivers.
美國作家、薩克拉門托之女瓊·迪迪恩曾描述過生活在山谷河流旁的不確定性。
「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.」
她寫道：「我想到了河水上漲的情景，想聽收音機里的聲音，想知道河水會漲到什麼高度，想知道防洪堤會不會被衝垮，何時何地被衝垮。」
（恭喜讀完，本篇英語辭彙量711左右）
原文出自：2023年1月14日《The Economist》United States版塊。
精讀筆記來源於：自由英語之路
本文翻譯整理: Irene
本文編輯校對: Irene
僅供個人英語學習交流使用。
【補充資料】（來自於網路）
加州之所以被稱為"黃金之州"，因為黃金在該州的歷史上扮演了重要的角色。居民還提到了金罌粟，一種當地的花，在全州都能找到大量的生長。加州太平洋沿岸的夕陽常常是美麗的黃色。加州立法機構在1968年將"金州"定為官方昵稱。
大氣層河流（atmospheric river）是位於對流層下層的，天氣尺度的狹長水汽輸送路徑。大氣層河流可見於熱帶至中緯度地區的洋面，可在全年出現，其出現時通常伴隨有海洋性氣旋、鋒面活動和低空急流 。科學家認為最大的「大氣層河流」的蓄水量相當於世界上最大河流亞馬遜河。
蒸發需求(evaporative demand)是指在一定氣象條件下從自由水面通過蒸發進入大氣的最大水量，通常用蒸發掉的水層厚度的毫米數表示。蒸發量的空間變化，受氣溫、海陸、降水量等因素的影響。緯度越低，氣溫越高，蒸發能力越強，蒸發量也就越大；在溫度相同條件下，海洋上的蒸發量高於內陸，並有自沿海向內陸顯著減少的趨勢；一般而言，降水量多的地方蒸發量也大，反之，蒸發量小。
天氣鞭打事件定義為從一個持續的大尺度循環狀態到另一個明顯不同的循環狀態的過渡。天氣鞭打可能會從持續的乾旱變成暴洪，或者從寒流變成異常高溫。再或者，比如，可能從颶風季一個怪異的平靜8月到歷史性的颶風伊恩襲擊了佛羅里達。
河流在洪水期溢出河床後堆積而成的平原。即河漫灘平原，在河流的中下段。泛濫平原發源於毗鄰江、河道的地方。當河植的斜坡容納不了河內的洪水徑流而形成不能共存的關係時，便開始形成泛濫平原 floodplains。
地下水盆地（groundwater basin）是水文地質學，是地下水盆地是承壓水盆地和潛水盆地的總稱。
瓊·狄迪恩（Joan Didion，1934年12月5日-2021年12月23日），美國隨筆作家和小說家，她的文風以強烈的情感為特點，給人以一種落葉無根的感覺，表現出超然世外的態度。此外，她還把對社會的審視和個人懺悔融合進了作品中。2021年12月23日，瓊·狄迪恩因帕金森併發症，在紐約曼哈頓家中去世，享年87歲。
【重點句子】（3 個）
At their most severe, they rival the hurricanes that clobber America』s east coast.
在最嚴重的時候，暴風雨可以與襲擊美國東海岸的颶風媲美。
But the Golden State』s severe drought and flooding are both consequences of the warming climate, as the relationship between wildfires and floods suggests.
但加州嚴重的乾旱和洪水都是氣候變暖的結果，就像野火和洪水之間的關係一樣。
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適應不同類型的極端天氣，不僅限於缺水問題。
自由英語之路
