那些凉爽宜人的夏夜发生了什么事?

那些凉爽宜人的夏夜发生了什么事?

One of the best parts about the waning days of summer are the cool summer nights. After a humid, hot day, you look forward to the evening when the temperature dips as the sun goes down.

夏夜是炎炎夏日渐逝的最好时光之一。在潮湿炎热的一天之后，你期待着太阳下山时气温下降的夜晚。

But those cool summer nights seem to be a victim of climate change.

但那些凉爽的夏夜似乎是气候变化的受害者。

This July was the hottest month ever measured. And as summer days continue to get more scorching, it's harder for evenings to cool off.

今年7月是有史以来最热的一个月。随着夏天越来越热，晚上很难凉快下来。

Photo: Zurijeta/Shutterstock

Climate change journalist Robinson Meyer writes in The Atlantic, "Across the lower 48 states, summer nights are now warmer than they have been at any other point since 1900, according to data from the climate scientist Zeke Hausfather. Daily minima—in other words, the temperature at the coolest part of the night—are regularly hotter now than they were even during the warmest years of the Dust Bowl. Daytime highs have actually yet to eclipse that mark."

气候变化记者罗宾逊·迈耶在《大西洋月刊》上写道:“根据气候科学家齐克·豪萨尔特的数据，在美国48个较低的州，夏夜比1900年以来的任何时候都要温暖。”每天的最低气温——换句话说，夜晚最冷的时候的气温比沙尘暴最温暖的时候还要高。实际上，白天的高点还没有超过这个水平。”

Warm nights have become more common throughout the U.S. A recent climate assessment from North Carolina State University looked specifically in the Southeast and found large increases in nighttime temperatures with modest increases in daytime temperatures.

温暖的夜晚在美国变得越来越普遍。北卡罗来纳州立大学最近对美国东南部地区进行的一项气候评估发现，夜间气温大幅上升，而白天气温则略有上升。

"The number of warm nights (minimum temperature above 75°F) has doubled on average compared to the first half of the 20th century and locally has increased at most [weather] stations," researchers wrote.

研究人员写道:“与20世纪上半叶相比，温暖的夜晚(最低温度在75华氏度以上)的数量平均增加了一倍，而且当地大多数气象站的夜间温度都有所上升。”

Record-breaking temps

破纪录的气温

The summer of 2018 was the hottest yet for nighttime temps. The nighttime temperature, averaged nationwide for June, July and August, was the hottest ever, recorded at 60.9 degrees, according to the National Oceanic and Atmospheric Administration (NOAA).

2018年夏天是夜间温度最高的一年。根据美国国家海洋和大气管理局(NOAA)的数据，美国6月、7月和8月的夜间平均气温是有史以来最高的，达到60.9度。

Every state had an above-average summer minimum temperature. Meteorologists define summer as June 1 through Aug. 31.

每个州的夏季最低气温都高于平均水平。气象学家将夏季定义为6月1日至8月31日。

When the atmosphere can't cool off at night, it's a sign of global warming due to human-caused conditions, according to NOAA and other climate experts.

美国国家海洋和大气管理局(NOAA)和其他气候专家表示，当大气在夜间无法降温时，这是由于人为因素导致的全球变暖的迹象。

"In general, since records began in 1895, summer overnight low temperatures are warming at a rate nearly twice as fast as afternoon high temperatures for the U.S. and the 10 warmest summer minimum temperatures have all occurred since 2002," NOAA said in a statement.

美国国家海洋和大气管理局在一份声明中说:“总的来说，自从1895年有记录以来，夏季夜间低温变暖的速度几乎是美国下午高温变暖速度的两倍。自2002年以来，夏季10个最温暖的最低气温都出现过。”

And sweltering summer nights aren't just an inconvenience; they can be dangerous.

闷热的夏夜不仅给人带来不便;它们可能很危险。

"The combination of high daytime and high nighttime temperatures can be really lethal because the body doesn’t have a chance to cool down during the nighttime hours," Lara Cushing, professor of environmental epidemiology at San Francisco State University, told The New York Times.

旧金山州立大学环境流行病学教授劳拉·库欣在接受《纽约时报》采访时表示:“白天高温和夜间高温的结合可能会造成致命的后果，因为人体在夜间没有机会降温。”

And those risks are higher in places like the California coast, where people aren't used to soaring temperatures.

而在加州海岸等人们不习惯气温飙升的地方，这种风险更高。

"A hundred and five degrees in San Francisco is going to have a bigger impact probably than 105 degrees in Houston, Texas, where everybody has air conditioning and people are accustomed to dealing with high temperatures."

“旧金山的105度将比德克萨斯州休斯顿的105度产生更大的影响，那里每个人都有空调，人们已经习惯了应对高温。”