2 . In the endless sky, the unaided human eye should be able to perceive several thousand stars on a clear, dark night. Unfortunately, growing light pollution has impeded people from the nightly view.

New citizen-science-based research throws alarming light on the problem of “sky glow”-the diffuse illumination (漫射照明) of the night sky that is a form of light pollution. The data came from crowd-sourced observations collected from around the world as part of Globe at Night, a program developed by astronomer Connie Walker.

Light pollution has harmful effects on the practice of astronomy but also on human health and wildlife, since it disturbs the cycle from sunlight to starlight that biological systems have evolved alongside. Furthermore, the loss of visible stars is a great loss of human cultural heritage. Until relatively recently, humans throughout history had an impressive view of the starry night sky, and the effect of this nighty spectacle (壮观) is evident in ancient cultures.

Globe at Night has been gathering data on star visibility since 2006. Anyone can submit observations through the Globe at Night web application. Participants record which one best matches what they can see in the sky without any telescopes or other instruments.

Researchers find that the loss of visible stars indicates an increase in sky brightness of 9.6% per year while roughly 2% is measured by satellites. Existing satellites are not well suited to measuring sky glow as it appears to humans, because they can not detect wavelengths shorter than 500 nanometers (纳米). White LEDs, with shorter wavelengths under 500 nanometers, now are increasingly commonly used in outdoor lighting. But human eyes are more sensitive to these shorter wavelengths at nighttime. Space-based instruments do not measure light from windows, either. But these sources are significant contributors to sky glow us seen from the ground.

“The increase in sky glow over the past decade underlines the importance of redoubling our efforts and developing new strategies to protect dark skies,” said Walker. “The Globe at Night dataset is necessary in our ongoing evaluation of changes in sky glow, and we encourage whoever can to get involved to help protect the starry night sky.”

E-TRASH

Nowadays, every household produces electronic trash (or e-trash)—an old TV or computer, a printer, or an out-of-date cell phone. But when we throw these everyday items away, not many of us know    1    they go. The journalist and photographer, Peter Essick, decided to follow this e-trash    2    several countries around the world.

In particular, Essick found that a lot of e-trash goes to Ghana. There, he saw    3    (mountain) of old computers in the local markets. The sellers resell some of them,    4     not many work. Instead, they recycle the broken computers by melting the parts inside. These parts contain a little metal such as copper or even gold. However, this recycling process is    5    (danger) for the workers because    6    produces a lot of toxic chemicals.

As a result of his journey, Peter Essick thinks it’s important to stop     7    (export) e-trash. It’s bad for the environment and it’s bad for    8    (people) health. Instead, he believes manufacturers need    9     (produce) more eco-friendly electronics, in other words, electronic products that you can recycle cheaply, safely, and in the country where they    10    (make).

7 . Scientists visiting tiny Henderson Island in the South Pacific recently made an alarming discovery.     1    They calculated there were 38 million pieces of plastic. “This is not an issue to ignore. We need to do something now to protect the sea.” said one scientist.

Plastic waste in the sea has long been known about, but only now are we discovering the true extent of the problem. Plastic takes hundreds of years to decompose, so all the plastic ever produced still exists somewhere. Around 95% of plastics made are not recycled, and large amounts enter the sea. Currents(洋流) collect this waste in large circular systems called “gyres”.     2    

The problem gets worse as plastic breaks down into very small pieces, or “micro plastic”,     3     Humans also eat these fish, and micro plastic has even been found in tap water around the world. The plastic on Henderson Island accounts for just 2 seconds’ worth of global annual plastic production. That production will be three times by 2050.

    4     While diving in Greece, young Boyan Slat noticed there was more plastic waste than fish. He decided right then to dedicate his life to solving this problem. Boyan thought, why move through the sea when the sea can move through you? So he started The Ocean Cleanup project, which places very long floating barriers in the Pacific. Currents then concentrate the waste naturally so it can be collected and recycled. He hopes to reduce the patch by 50% in just five years.

“Sea plastic is a symbol of the negative effects of our lifestyle and technology,” he says. “    5     Protecting the sea from plastic is a good place to start!”

8 . Cotton bags have become a means for brands, retailers and supermarkets to convey a planet-friendly mindset — or, at least, to show that the companies are aware of the overuse of plastic in packaging.

Earth-friendly? Not exactly. It turns out the wholehearted embrace of cotton bags may actually have created a new problem. An organic cotton bag needs to be used 20,000 times to make up for its overall impact of production, according to a 2018 study by the Ministry of Environment and Food of Denmark. That is equal to daily use for 54 years — for just one bag. The production of cotton bags is water-intensive, and figuring out how to deal with a bag in an environmentally low-impact way is not nearly as simple as people think, according to Travis Wagner, an environmental science professor at the University of Maine.

In sharp comparison with the frequent use of cotton bags, the disposal (处理) of the bags remains less satisfying. Only 15 percent of the 30 million tons of cotton bags produced every year actually is sent to be recycled. Even when a bag does make it to a treatment facility, most dyes (染料) used to print logos onto them are PVC-based and thus not recyclable; “they’re extremely difficult to disintegrate (分解) chemically,” said Christopher Stanev, the co-founder of Evrnu, a Seattle-based textile recycling firm. Printed patterns have to be cut out of the cloth; Mr. Stanev estimates 10 to 15 percent of the cotton Evrnu receives is wasted this way.

That’s not to say cotton is worse than plastic, or that the two should even be compared. While cotton can use pesticides and has dried up rivers from water consumption, lightweight plastic bags use greenhouse gas-emitting fossil fuels and will fill up the oceans.

Buffy Reid, of the knitwear label & Daughter, stopped production of her cotton bags in April this year. Aesop is converting the composition of its shopping bags to a 60 — 40 blend of recycled and organic cotton. Designer Ally Capellino recently employed a new material, while Hindmarch introduced a new version of her original cotton bag, this time made from recycled water bottles.

In the end, the simplest solution may be the most obvious. “Not every product needs a bag,” Comey says.

9 . If humans were truly at home under the light of the moon and stars, we would go in darkness happily, the midnight world as visible to us as it is to the vast number of nocturnal (夜间活动的) species on this planet. Instead, we are diurnal creatures, with eyes adapted to living in the sun’s light. This is a basic evolutionary fact, even though most of us don’t think of ourselves as diurnal beings. Yet it’s the only way to explain                    what we’ve done to the night: We’ve engineered it to receive us by filling it with light.

The benefits of this kind of engineering come with consequences -- called light pollution -- whose effects scientists are only now beginning to study. Light pollution is largely the result of bad lighting design, which allows artificial light to shine outward and upward into the sky. Ill-designed lighting washes out the darkness of night and completely changes the light levels -- and light rhythms -- to which many forms of life, including ourselves, have adapted. Wherever human light spills into the natural world, some aspect of life is affected.

In most cities the sky looks as though it has been emptied of stars, leaving behind a vacant haze (霾) that mirrors our fear of the dark. We’ve grown so used to this orange haze that the original glory of an unlit night -- dark enough for the planet Venus to throw shadows on Earth -- is wholly beyond our experience, beyond memory almost.

We’ve lit up the night as if it were an unoccupied country, when nothing could be further from the truth. Among mammals alone, the number of nocturnal species is astonishing. Light is a powerful biological force, and on many species it acts as a magnet (磁铁). The effect is so powerful that scientists speak of songbirds and seabirds being “captured” by searchlights on land or by the light from gas flares on marine oil platforms. Migrating at night, birds tend to collide with brightly lit tall buildings.

Frogs living near brightly lit highways suffer nocturnal light levels that are as much as a million times brighter than normal, throwing nearly every aspect of their behavior out of joint, including their nighttime breeding choruses. Humans are no less trapped by light pollution than the frogs. Like most other creatures, we do need darkness. Darkness is as essential to our biological welfare, to our internal clockwork, as light itself.

Living in a glare of our own making, we have cut ourselves off from our evolutionary and cultural heritage-the light of the stars and the rhythms of day and night. In a very real sense, light pollution causes us to lose sight of our true place in the universe, to forget the scale of our being, which is best measured against the dimensions of a deep night with the Milky Way -- the edge of our galaxy -- arching overhead.

10 . Hardware in general, and smartphones in particular, have become a huge environmental and health problem in the Global South's landfill sites （垃圾填埋场）.

Electronic waste（ e-waste ） currently takes up 5 percent of all global waste, and it is set to increase rapidly as more of us own more than one smartphone, laptop and power bank. They end up in places like Agbogbloshie on the outskirts of Ghana's capital, Accra. It is the biggest e-waste dump in the world, where 10, 000 informal workers walk through tons of abandoned goods as part of an informal recycling process. They risk their health searching for the precious metals that are found in abandoned smartphones.

But Agbogbloshie should not exist. The Basel Convention, a 1989 treaty, aims to prevent developed nations from unauthorized dumping of e-waste in less developed countries. The e-waste industry, however, circumvents the regulations by exporting e-waste labelled as "secondhand goods" to poor countries like Ghana, knowing full well that it is heading for a landfill site.

A recent report found Agbogbloshie contained some of the most dangerous chemicals. This is not surprising: smartphones contain chemicals like mercury （水银），lead and even arsenic（砷）. Reportedly, one egg from a free-range chicken in Agbogbloshie contained a certain chemical which can cause cancer and damage the immune system at a level that's about 220 times greater than a limit set by the European Food Safety Authority（EFSA） . Most worryingly, these poisonous chemicals are free to pollute the broader soil and water system. This should concern us all, since some of Ghana's top exports are cocoa and nuts.

Some governments have started to take responsibility for their consumers' waste. For example, Germany has started a project that includes a sustainable （可持续的）recycling system at Agbogbloshie, along with a health clinic for workers. However, governments cannot solve the problem alone, as there is an almost limitless consumer demand for hardware, especially when governments green policies are focused on issues like climate change.

Only the manufacturers can fix this. A more economically sustainable and politically possible solution is through encouraging hardware manufacturers to make the repair, reuse and recycling of hardware profitable, or at least cost-neutral.