来源：《新科学家》
原文见刊日期：2022年5月28日
Eco-anxiety is already causing people to lose sleep over climate change. Now, a global study has found that a warming planet is also affecting how long people sleep, and the problem will get worse this century even if humanity manages to rein in its carbon emissions.
生态焦虑已经导致人们因气候变化而失眠。现在，一项全球研究发现，全球变暖也在影响人们的睡眠时间，即使人类设法控制碳排放，这个问题在本世纪也会变得更糟。
Our measurements of the impact of above-average night temperatures on sleep have previously been limited by being confined to single countries, lab studies or notoriously unreliable self-reporting of sleep.
此前，我们对夜间温度高于平均水平对睡眠影响的测量一直受到限制，因为这些测量仅限于单个国家、实验室研究或众所周知不可靠的睡眠自我报告。
To glean a better real-world picture, Kelton Minor at the University of Copenhagen, Denmark, took data from sleep-tracking wristbands used by 48,000 people in 68 countries between 2015 and 2017.
为了更好地获得真实世界的情况，丹麦哥本哈根大学的凯尔顿·迈纳从68个国家的4.8万人在2015年至2017年期间使用的睡眠追踪腕带中获取了数据。
He and his colleagues then paired the sleep data with local weather data, revealing that unusually hot nights are causing people to fall asleep later, rise earlier and sleep less. Already, the evidence suggests that people are losing an average of 44 hours of sleep each year. By 2100, the researchers estimate people will lose 58 hours of sleep a year if emissions go unchecked. In a lower-emissions future, the figure drops to 50 hours.
然后，他和同事将睡眠数据与当地天气数据进行了配对，发现异常炎热的夜晚导致人们睡得更晚、起得更早、睡得更少。已经有证据表明，人们每年平均失去44小时的睡眠时间。研究人员估计，到2100年，如果排放不受控制，人们每年将少睡58个小时。在低排放的未来，这一数字将降至50小时。
“This is the first planetary-scale evidence that warmer-than-average temperatures erode human sleep. We show that sleep erosion occurs primarily by delaying when people fall asleep,” says Minor.
“这是第一个在全球尺度上的证据，表明高于平均水平的温度会损害人类的睡眠。我们发现，睡眠损害主要是由于人们入睡时间延迟造成的，”迈纳说。
Some groups are hit worse than others. Above-average heat at night had a larger impact on sleep loss for people in lower-income countries, women and older people. For those aged 65 and older, the effect on sleep of a 1°C increase in the minimum overnight temperature was at least twice that of younger age groups.
有些群体受到的打击比其他群体更严重。对于低收入国家的人们、妇女和老年人来说，夜间高于平均水平的高温对睡眠不足的影响更大。对于65岁及以上的老年人来说，夜间最低气温升高1摄氏度对睡眠的影响至少是年轻人群的两倍。
It is possible that some of those living in higher-income countries are more likely to install air conditioning to help them cope with the heat, but Minor says the findings in the study don’t allow him to make this link definitively. Moreover, air conditioning can drive up emissions due to fossil fuel energy use.
可能生活在高收入国家的一些人更有可能安装空调来帮助他们应对炎热，但迈纳表示，研究结果不能让他确定这两者之间的联系。此外，由于发电使用化石燃料，空调会增加排放。
Susan Clayton at the College of Wooster, Ohio, says the study’s methodology is sound and includes a “very thorough” examination of other explanations. “The implications are clear: higher temperatures associated with climate change are already reducing the amount of sleep people get and are projected to do so even more. Since we know that lack of sleep can negatively impact mood, behaviour and health, this is concerning,” she says.
俄亥俄州伍斯特学院的苏珊·克莱顿说，这项研究的方法是合理的，包括对其他解释的“非常彻底”的检查。“其影响是显而易见的：与气候变化相关的高温已经在减少人们的睡眠时间，预计还会减少更多。因为我们知道缺乏睡眠会对情绪、行为和健康产生负面影响，这是令人担忧的。”
Ivana Rosenzweig at King’s College London says the study showcases the power of big data. But she says the measured effect when considered from the perspective of a single night is small. “Mere minutes of sleep per night,” she says.
伦敦国王学院的伊凡娜·罗森茨威格表示，这项研究展示了大数据的力量。但她说，从一个晚上的角度考虑，测量到的影响很小。“每晚只少睡几分钟，”她说。
However, Minor says the type of person who chooses to wear a sleep-tracker may also be more likely to have access to other technologies that can curb the effect of hot nights on their sleep. For that reason, he says the team’s estimates of climate change’s impact on sleep are likely to be on the low side.
然而，迈纳表示，选择佩戴睡眠追踪器的人也更有可能使用其他技术，这些技术可以抑制炎热夜晚对他们睡眠的影响。因此，他说，该团队对气候变化对睡眠影响的估计可能偏低。