1 . Steven Stein likes to follow garbage trucks. His strange habit makes sense when you consider that he’s an environmental scientist who studies how to reduce litter, including things that fall off garbage trucks as they drive down the road. What is even more interesting is that one of Stein’s jobs is defending an industry behind the plastic shopping bags.

Americans use more than 100 billion thin film plastic bags every year. So many end up in tree branches or along highways that a growing number of cities do not allow them at checkouts(收银台). The bags are prohibited in some 90 cities in California, including Los Angeles. Eyeing these headwinds, plastic-bag makers are hiring scientists like Stein to make the case that their products are not as bad for the planet as most people assume.

Among the bag makers’ argument: many cities with bans still allow shoppers to purchase paper bags, which are easily recycled but require more energy to produce and transport. And while plastic bags may be ugly to look at, they represent a small percentage of all garbage on the ground today.

The industry has also taken aim at the product that has appeared as its replacement: reusable shopping bags. The stronger a reusable bag is, the longer its life and the more plastic-bag use it cancels out. However, longer-lasting reusable bags often require more energy to make. One study found that a cotton bag must be used at least 131 times to be better for the planet than plastic.

Environmentalists don’t dispute(质疑) these points. They hope paper bags will be banned someday too and want shoppers to use the same reusable bags for years.

2 . Since the first Earth Day in 1970, Americans have gotten a lot “greener” toward the environment. “We didn’t know at that time there even was an environment, let alone that there was a problem with it,” says Bruce Anderson, president of Earth Day USA.

But what began as nothing important in public affairs has grown into a social movement .Business people, political leaders, university professors, and especially millions of grass-roots Americans are taking part in the movement. “The understanding has increased many， many times,” says Gaylord Nelson, the former governor from Wisconsin, who thought up the first. According to US government reports, emissions (排放)from cars and trucks have dropped from 10.3 million tons a year to 5.5 tons .The number of cities producing CO beyond the standard has been reduced from 40 to 9. Although serious problems still remain and need to be dealt with, the world is a safer and healthier place. A kind of “Green thinking” has become part of practices.

Great improvement has been achieved. In 1988 there were only 600 recycling programs; today in 1995 there are about 6,600. Advanced lights, motors, and building designs have helped save a lot of energy and therefore prevented pollution.

Twenty –five years ago, there were hardly any education programs for environment. Today, it’s hard to find a public school, university, or law school that does not have such a kind of program. “Until we do that, nothing else will change!” says Bruce Anderson.

3 . Masks that helped save lives are proving a deadly danger for wildlife, with birds and sea creatures trapped in the shocking number of thrown-away facial coverings. Single-use masks have been found around pavements, waterways and beaches worldwide. Worn once, the thin protective materials can take hundreds of years to decompose. “Face masks aren't going away any time soon—but when we throw them away, these items can harm the environment and the animals,” Ashley Fruno of animal rights group PETA said.

In Britain, a gull was rescued by the RSPCA after its legs became tangled in the straps of a mask for up to a week. The animal welfare charity took it to a wildlife hospital for treatment before its release.

The biggest impact may be in the water. More than 1.5 billion masks made their way into the world's oceans last year, accounting for around 6,200 extra tonnes of ocean plastic pollution, according to environmental group Oceans Asia.

Conservationists in Brazil found one mask inside the stomach of a penguin after its body was washed up on a beach, while a dead pufferfish was discovered caught inside another off the coast of Miami. French campaigners found a dead crab trapped in a mask near the Mediterranean. Masks and gloves are “particularly problematic” for sea creatures, says George Leonard, chief scientist from NGO Ocean Conservancy. “When those plastics break down in the environment, they then enter the food chain and impact entire ecosystems.” he added.

There has been a shift towards greater use of reusable cloth masks as the pandemic has worn on, but many are still using the lighter single-use varieties. Campaigners have urged people to bin them properly and cut the straps to reduce the risk of animals becoming trapped. Oceans Asia has also called on governments to increase fines for littering and encourage the use of washable masks.

Last Sunday we took a part in a clean-up activity in a forest outside the city. When we arrived, we were sad to see rubbishes everywhere. Though there was a “Do Not Litter” sign at the entrance, that didn’t stop people litter around.   Our team leader, Jim, divided us by two groups - one cleaned up the north side of the forest and the other cleaned up the south side. We cleared up a lot of waste we were very happy to see the forest looked clean than before. It was absolutely worth our effort! There will be other clean-up activity in the green belt next Sunday. You can contact Jim and sign up for it if you’re willingly to help. Whoever participated will receive a medal like last time. I’ll join you too until I have time.

5 . In the old days, when you had to drive to a movie theater to get some entertainment, it was easy to see how your actions could have an impact on the environment. After all, you were jumping into your car, driving across towns, coughing out emissions (排放) and using gas all the way. But now that we’re used to staying at home and streaming (流式传输) movies, we might get a little proud. After all, we’re just picking up our phones and maybe turning on the TV. You’re welcome. Mother Nature.

Not so fast, says a recent report from the French-based Shit Project. According to Climate Crisis: The Unsustainable Use of Online Video, digital technologies are responsible for 4% of greenhouse gas emissions, and that energy use is increasing by 9% a year. Watching a half-hour show would lead to 3.5 pounds of CO2 emissions. That’s like driving 6.28 kilometers. And in the European Union, the Eureca project found that data centers (where videos are stored) there used 25% more energy in 2017 compared to just three years earlier, reports the BBC.

Streaming is only expected to increase as we become more enamored of our digital devices (设备) and the possibility of enjoying entertainment where and when we want it to increase. Online video use is expected to increase by four times from 2017 to 2022 and account for 80% of all Internet traffic by 2022. By then, about 60% of the world’s population will be online.

You’re probably not going to give up your streaming services, but there’re things you can do to help lessen the impact of your online use, experts say. For example, according to Lutz Stobbe, a researcher from the Fraunhofer Institute in Berlin, we have no need to upload 25 pictures of the same thing to the cloud because it consumes energy every time. If instead you delete a few things here and there, you can save energy. Moreover, it’s also a good idea to stream over Wi-Fi, watch on the smallest screen as you can, and turn off your Wi-Fi in your home if you’re not using your devices.

7 . Clothing rental is a hot new industry and retailers (零售商) are demanding to get on board in hopes of attracting green shopper.

But is renting fashion actually more environmentally-friendly than buying it, and if so, how much more? Journalist and author Elizabeth Cline investigated (调查) this question and concluded that it's not as sustainable as it seems.

Take shipping, for example, which has to go two ways if an item is rented — receiving and returning. Cline writes that consumer transportation has the second largest carbon footprint of our collective fashion habit after manufacturing.

She writes, ''An item ordered online and then returned can send out 20 kilograms of carbon each way, and increases up to 50 kilograms for rush shipping. By comparison, the carbon impact of a pair of jeans purchased from a physical store and washed and worn at home is 33.4 kilograms, according to a 2015 study by Levi's.''

Then there's the burden of washing, which has to happen for every item when it's returned, regardless of whether or not it was worn. For most rental services, this usually means dry cleaning, a high impact and polluting process. All the rental services that Cline looked into have replaced perchloroethylene (氯乙烯), a carcinogenic (致癌的) air pollutant, still used by 70 percent of US dry cleaners, with alternatives, although these aren't great either.

Lastly, Cline fears that rental services will increase our appetite for fast fashion, simply because it's so easily accessible. There's something called ''share washing'' that makes people waste more precisely because a product or service is shared and thus is regarded as more eco-friendly. Uber is one example of this, advertised as ''a way to share rides and limit ear ownership.'' and yet ''it has been proven to discourage walking,bicycling, and public transportation use.''

Renting clothes is still preferable to buying them cheap and throwing them in the dustbin after a few wears, but we shouldn't let the availability of these services make us too satisfied. There's an even better step — that's wearing what is already in the closet.

8 . The endangered pandas in the Qinling Mountains might face a new threat: the loss of their food, bamboo, which makes up 99% of their meals.

Adult pandas spend most part of the day eating bamboo and have to take in at least 40 pounds a day to stay healthy. However, a new study published in Nature Climate Change warned that they may soon find their food gone because most of the bamboo in the Qinling Mountains might disappear by the end of the century as a result of rising temperature worldwide.

A team made up of researchers from Michigan State University and the Chinese Academy of Sciences has studied the effects of climate change on the bamboo in the Qinling Mountains. They have found that bamboo is very sensitive to climate changes. “80% to 100% of the bamboo would be gone if the average temperature rises 3.5 degrees worldwide by the end of the century,” said Liu Jianguo, one of the report’s authors.

He added, “This is how much the temperature would rise by 2100 even if all countries will keep their promises in the Paris Agreement. But you know what is happening all around the world.”

In recent years, China has been trying its best to protect the endangered pandas by setting up more and bigger natural reserves.

“But it is far from enough and the endangered pandas need cooperation from the rest of the world, because their future is not just in the hands of the Chinese,” said Shirley Martin from the World Wildlife Fund but not a member of the team.

The Qinling Mountains, in the southwest of China, are home to about 260 pandas. That is about 13% of China’s wild panda population. In addition, about 375 are living in research centers and zoos in China.

9 . As heat waves continue to ravage the planet, air conditioners are becoming more and more common. However, these "active" cooling devices are posing problems because the electricity consumption which most people are concerned about and the release of ozone-damaging chemicals worsen the greenhouse gas effect, resulting in the creation of heat islands and further thermal pollution. Therefore, "passive" cooling, which doesn't have such effects, has attracted considerable attention from both scientists and ordinary people in recent years.

In a recent study, a team of researchers from China and US presented an eco-friendly, low-cost smart coating to keep buildings cooler while consuming zero electricity. Infrared radiation-based passive cooling has been investigated since 2014, but challenges, mainly the expensive and unsustainable design, have greatly limited their large-scale and widespread application. Besides, the imbalance in cooling ability of these coatings during the day and night tends to lead to great day-night temperature differences as more heat is lost than gained at night.

The solution therefore requires a "smart" mechanism that can both enhance daytime cooling and minimize nighttime heat loss. To do this, the researchers created a new smart coating comprised of conventional building materials, including titanium dioxide nanoparticles, fluorescent microparticles, and glass microspheres that were engineered to reflect most of the sunlight. Specifically, the titanium dioxide particles effectively reflect sunlight through light scattering（撒播）while the fluorescent particles increase the amount of reflection by changing the absorbed sunlight into fluorescence emissions, which drive more heat away from the building. Meanwhile, the glass microspheres re-send mid-infrared broadband radiation, allowing not only heat loss, but allowing heat exchange to take place between the building and the sky.

The coating was tested on a model concrete building. Through this efficient heat exchange with the sky, daytime cooling was strengthened while nighttime cooling was reduced. The building's inside temperature was always maintained at around 26℃, even when the out-side temperature varied from 24℃ to 37℃ during the day. We believe this new coating will make it to commercialization soon, enabling a sustainable, passive cooling technology that could help to fight climate change and the global energy crisis.