【推荐1】In the past few decades, the way we shop has changed dramatically. We used to buy our goods in traditional shops. Now, customers are increasingly buying online, where they can order whatever they want directly to their door with the click of a mouse. As companies race to improve their Internet shopping experience, the trend towards shopping online is predicted to continue.

Most people commonly think that online shopping is better than in-store shopping. After all, an online store does not use the electricity that a traditional store might use and it doesn't require the customer to drive anywhere. So you would think the carbon savings must be significant.

Take the typical home delivery round in the UK, for example. Supermarket drivers often do 120 deliveries on an 80-kilometre round, producing 20 kilograms of CO₂ in total. In contrast, a 21-kilometre drive to the store and back for one household would generate 24 times more CO₂! However, the reality is slightly more complex than that. Many home deliveries fail the first time and the driver has to make a second or third attempt to deliver the purchase.

The carbon footprint also goes up if the customer chooses to return the item. A study in Germany shows that as many as one in three online purchases are returned. According to another study, merchandise worth nearly $ 326 million is returned each year in the USA. Two billion kilograms of this ends up in landfill, leading to 13 tons of CO₂ being released.

When we take all these factors into consideration, we realize that online shopping isn't necessarily as green as people might think. There is some positive news, as various online retailers are starting to lower their carbon footprint by turning to electric delivery vehicles. However, the question of how to deal with returns efficiently and without waste is a challenge that many companies have not wanted to face, but they have to shoulder responsibilities.

【推荐2】Is there anything Sponges (海绵) can’t do? For thousands of years, humans have used dried natural sponges to clean up, to paint and as containers to consume liquids like water or honey. And, as scientists around the world are beginning to show, sponges’ cavity-filled (空腔填充) forms mean they could provide a solution to one of our era’s biggest problems: microplastic pollution.

In August, researchers in China published a study describing their development of a man-made sponge that makes short work of microscopic plastic debris (碎片). In tests, the researchers show that when a specially prepared plastic-filled solution is pushed through one of their sponges, the sponge can remove both microplastics and even smaller nanoplastics from the liquid. These particles typically become trapped in the sponge’s many openings. Though the sponges’ effectiveness varied in experiments, in part depending on the concentration of plastic and the acidity and saltiness of the liquid, the best conditions allowed the researchers to remove as much as 90 percent of the microplastics. They tried it in everything from tap water and seawater to — why not — soup from a local takeout spot.

According to Guoging Wang, a materials chemist at Ocean University of China and co-author on the paper, the sponge formula is adjustable. By adjusting the temperature when the two compounds are mixed, he says, the sponges can be made more or less porous (渗透). This affects the size of particles collected — highly porous sponges have lots of very small pores, which is good for catching very tiny particles. The sponges, if ever produced at an industrial scale, Wang says, could be used in wastewater treatment plants to remove microplastics out of the water or in food production facilities to depollute water.

There are hiccups to the sponge’s potential adoption, though What’s still lacking, says AliceHorton at the United Kingdom’s National Oceanography Center, is proof that any of these newer sponge-based technologies can be cost effective and successful in removing microplastics from water at a large scale. But one thing she is confident about is that efforts to remove microplastics after they have already reached the ocean are probably doomed to fail.

“I don’t think there is anything we can do on a large enough scale that will have any impact,” she says of that. “We have to stop it getting there in the first place.”

【推荐3】Most adults have lower levels of concern about climate change than do young people. Yet it's adults who have the power to affect the policies contributing to climate change. Now a new study shows that adolescents may be able to raise their parents' concerns about climate change. The key: Talk about the issues and share what you've been learning at school.

Young students can understand complex subjects, says Danielle Lawson. As a scientist who studies how people communicate about climate change, Lawson is part of a team that tested the ability of adolescents to teach their parents about climate change.

For a new study, teachers used a new curriculum with 10-to-14-year-old students. It involved more than just lessons about climate change. The students also took part in projects. “One example was collecting and sampling marine plants,” Lawson says. Students wrote blog posts about what they learned and shared those with others. The students also interviewed their parents. Someone might ask her dad, for instance, what changes he'd seen in their hometown's weather over time.

“Parents of girls were more likely to show more concern about climate change after the new program was used. Other studies find that girls in this age group usually have better communication skills than boys,” Lawson says. And, she adds that some parents might not have talked much about science with girls before the program. So the new program might have made girls feel more confident about sharing their concerns about climate issues.

Hilary Boudet has done similar research with children and families on lessons covering ways to save energy. “The idea of young people engaging with their parents is an important, yet underexplored pathway for change," says Boudet. She found the new study's finding of greater impacts of daughters and the ability of kids to change the attitudes of parents interesting. However, she says that more studies would still need to be done in other places. She also wishes the team had asked people about how they might have changed their behaviors after receiving the new lessons.

Lawson is hopeful that kids can boost parents understanding of climate science. “I know how powerful kids can be,” Lawson says. And, she notes, you don't need a special curriculum to discuss climate issues at home. “Talk to your parents about what you see going on,” She says, “Don't be afraid to share your thoughts." “And I don't feel discouraged if you don't change your parents' minds after one chat", she adds.