The spread of lit areas could threaten animal ecology and human health
照明区域的蔓延可能威胁动物生态和人类健康

Composite image of Europe and North Africa at night, 2016. Credit: NASA Earth Observatory images by Joshua Stevens, using Suomi NPP VIIRS data from Miguel Roman, NASA's Goddard Space Flight Center Artificial light is often seen as a sign of progress：the march of civilization shines a light in the dark; it takes back the night; it illuminates. But a chorus of scientists and advocates argues that unnaturally bright nights are bad not just for astronomers but also for nocturnal animals and even for human health.
2016年夜间欧洲和北非的合成图像。资料来源：NASA地球观测站图片，作者Joshua Stevens，使用NASA戈达德太空飞行中心Miguel Roman的Suomi NPP VIIRS数据。人造光通常被视为进步的标志：文明的前进在黑暗中闪耀着光芒；它夺回了夜晚；它亮了。但科学家和支持者们一致认为，非自然的明亮夜晚不仅不利于天文学家，也不利于夜间活动的动物甚至人类健康。

Now research shows the night is getting even brighter. From 2012 to 2016 the earth’s artificially lit area expanded by an estimated 2.2 percent a year (map), according to a study published last November in Science Advances. Even that increase may understate the problem, however. The measurement excludes light from most of the energy-efficient LED lamps that have been replacing sodium-vapor technology in cities all over the world, says lead study author Christopher Kyba, a postdoctoral researcher at the German Research Center for Geosciences in Potsdam.
现在研究表明，夜晚变得更加明亮。根据去年11月发表在《科学进展》杂志上的一项研究，从2012年到2016年，地球的人工照明面积估计每年扩大2.2%（地图）。然而，即使这样的增长也可能低估了问题。位于波茨坦的德国地球科学研究中心的博士后研究员克里斯托弗·基巴表示，这项测量不包括世界各地城市中取代钠蒸气技术的大多数节能LED灯的光。

The new data came from a NASA satellite instrument called the Visible Infrared Imaging Radiometer Suite (VIIRS). It can measure long wavelengths of light, such as those produced by traditional yellow-and-orange sodium-vapor street lamps.
新数据来自NASA的一个卫星仪器，名为可见红外成像辐射计套件（VIIRS）。它可以测量长波长的光，例如传统的黄色和橙色钠蒸气路灯产生的光。

But VIIRS cannot see the short-wavelength blue light produced by white LEDs. This light has been shown to disrupt human sleep cycles and nocturnal animals’ behavior.
但VIIRS无法看到白色LED发出的短波蓝光。这种光已经被证明会扰乱人类的睡眠周期和夜间动物的行为。

Credit: Mapping Specialists; Source: “Artificially Lit Surface of Earth at Night Increasing in Radiance and Extent, ”by Christopher C. M. Kyba et al., in Science Advances, Vol. 3, No, 11, Article No. E1701528; November 22, 2017.
测绘专家；资料来源：克里斯托弗·基巴等人的《科学进展》，第3卷，第11期，文章编号E1701528，“夜间人工发光的地球表面亮度和范围增加”；2017年11月22日。

The team believes the ongoing switch to LEDs caused already bright countries such as Italy, the Netherlands, Spain and the U. S. to register as having stable levels of illumination in the VIIRS data. In contrast, most nations in South America, Africa and Asia brightened, suggesting increases in the use of traditional lighting. Australia actually appeared to lose lit area — but the researchers say that is because wildfires skewed the data.
该团队认为，正在进行的LED转换导致意大利、荷兰、西班牙和美国等已经很亮的国家在VIIRS数据中登记为具有稳定的照明水平。相比之下，南美洲、非洲和亚洲的大多数国家都变亮了，这表明传统照明的使用有所增加。事实上，澳大利亚似乎失去了照明区域，但研究人员表示，这是因为野火扭曲了数据。

“The fact that VIIRS finds an increase [in many countries], despite its blindness in the part of the spectrum that increased more, is very sad,” says Fabio Falchi, a researcher at Italy's Light Pollution Science and Technology Institute, who did not participate in the study. In 2016 Falchi, along with Kyba and several other members of his research team, published a global atlas of artificial lighting that showed one third of the world's population currently lives under skies too bright to see the Milky Way at night.
意大利光污染科学技术研究所的研究员Fabio Falchi没有参与这项研究，他说：“在许多国家VIIRS在增加，尽管它在增加更多的光谱部分是盲目的，这一事实非常令人难过。”。2016年，Falchi、基巴和他的研究团队的其他几名成员一起发布了一份全球人工照明地图集，该地图集显示，目前世界上三分之一的人口生活在过于明亮的天空下，晚上看不到银河系。

The data also cast doubt on the idea that the LED lighting revolution will lead to energy cost savings. Between 2012 and 2016 the median nation pumped out 15 percent more long- wavelength light as its GDP increased by 13 percent. And overall, countries’ total light production correlated with their GDP. In other words, Kyba says, “We buy as much light as we are willing to spend money on.
这些数据也让人们对LED照明革命将带来能源成本节约的想法产生了怀疑。2012年至2016年间，随着GDP增长13%，中等国家的长波光输出量增加了15%。总体而言，各国的总光产量与其GDP相关。换句话说，基巴说：“我们愿意花钱买多少灯就买多少灯。