1 . We’re shopping online more than ever now, including various personal care and food items. Of U.S. Internet users, one-third do it at least once a week. Seeing your limited toilet paper (TP), you might pull up your smartphone and after a few taps have a fresh order of TP set to arrive in a day, maybe even less, and all done right from the toilet seat.

But this type of shopping — numerous small, quick-to-ship orders placed through e-tailing companies like Amazon — might be the worst for the environment, according to a recent study in Environmental Science & Technology. With their current business model of free shipping and fast delivery, greenhouse gas emissions linked with transporting “fast consumer goods” are high. “The online-only retailers are growing rapidly,” says lead author Sadegh, a scientist at Radboud University in the Netherlands.

Previous analyses haven’t agreed on whether online or in-store shopping is better. In fact, some studies have found that online shopping has a lower impact, because it saves the emissions associated with driving your car to the store (95 percent of Americans drive to go shopping). But this benefit can vary, or even disappear, depending on how fast we want that TP to arrive. And if you’re shopping in real life, factors like how you transport those items, how far you travel, and how much you buy at once all affect the carbon footprint of your purchase. “There have been some contradicting results, with some saying online shopping is better and some saying traditional shopping is better,” says Sadegh. So he tried to settle the debate with an approach that showed how likely one option was to be better than the other.

Sadegh and his team compared three shopping styles: traditional in-store shopping, online ordering from a physical store (which they called “bricks and clicks”), and ordering through an online-only retailer. Nearly two-thirds of the time, bricks and clicks shopping resulted in fewer emissions per item than in-store shopping — and was better than online shopping 97 percent of the time. In-store shopping had fewer emissions than online — only 81percent of the time.

6 . The rechargeable lithium-ion (锂离子) battery market is worth more than ＄50 billion. Lithium-ion batteries, whose demand continues to go up day by day, are used in a wide range of electronic devices. They are made of four main components, and cathode (阴极) is one of them. The cathode’s active material type is what determines the capacity of a battery.

A recent study, led by Wang Yan, a material scientist of Worcester Polytechnic Institute, finds that lithium-ion batteries made with recycled cathodes work better than those with new cathodes.

“The battery industry is expected to grow sharply in the next decade. This high demand has led companies to go to extremes, like increasing deep-sea mining, to gain access to the minerals used in lithium-ion batteries,” Wang said. “Mining minerals will have environmental impacts. Recycling spent lithium-ion batteries offers a way out.”

But until now, the prospect of using recycled materials in lithium-ion batteries has some manufacturers (制造商) worrying that it could impact performance. Thus, lithium-ion batteries are still not widely recycled. Aware of decreasing resources and environmental impact, Wang and other researchers set out to find a way to make recycling lithium-ion batteries economically practical. Through experiments, they could recover more than 90% of the key metals from spent batteries. These recovered metals became the basis of the new recycled battery’s cathode’s active material.

In tests between Wang’s team’s recycled batteries and brand-new batteries of the same composition, the recycled batteries outperform the new ones in their ability to maintain capacity. It took 11,600 charge cycles for recycled cathode batteries to lose 30 percent of their original capacity. That was about 50 percent better than the 7,600 observed cycles for new cathode batteries, the team reported. Those thousands of extra cycles could translate into years of better battery performance, even after repeated use and recharging.

7 . Concerns about microplastics are not new. They’ve been growing for more than a decade. Over the past two years, however, many creative solutions have emerged to address the problem on a local level. Still, experts say there’s a need for a huge effort if we want to curb (控制) the global issue.

The term microplastics was coined in 2004 by marine ecologist Richard Thompson after he discovered tiny bits of plastic littering British beaches. Since then, scientists have found microplastics nearly everywhere. Even inside us. According to a 2021 study in Environmental Toxicology and Chemistry, the physical presence of plastic inside the body poses a potential problem. Plastic’s chemical additives might also affect different species’ tissues and organs. However, there is disagreement as to how much microplastics harm species, including humans.

For a global view of this vast issue, Duke University scientists created a public database to track plastic removal innovations. For instance, the Hoola One is a vacuum that internally separates microplastics from organic materials. In Amsterdam, scientists have introduced the Bubble Barrier in canals, a device that creates a wall of bubbles to send submerged plastic to the surface. Hong Kong Polytechnic University researchers presented a unique idea — a bacteria biofilm that could attract and trap microplastics before they flow into rivers and oceans.

But “if you have a technology that would capture microplastics before they enter our waterways, that would be ideal,” says Zoie Diana, who added 40 new inventions this year. That’s where Alain Marty, chief scientist at the biochemistry start-up Carbios, comes into the picture. In a 2020 Nature article, Marty and colleagues describe how they engineered an enzyme (酶) to break down plastic efficiently. “Industries could employ that in their manufacturing processes so that nearly all of their material could be reused to create products. Marty’s discovery is a breakthrough in the right direction, though preventing microplastics by reducing our plastic use also matters,” says Diana. “We really want to turn off the tap.”

10 . In a remote corner of Brazil's Amazon tropical（热带的）rainforest, researchers have spent decades catching and measuring birds. Over 40 years, dozens of Amazonian bird species have declined in mass（质量）. Many species have lost nearly 2% of their average body weight each decade, researchers report November 12 in Science Advances. Some species have grown longer wings. The changes could help birds stay cool in a hotter, more changeable climate, the researchers say.

"Climate change isn't something of the future. It has been happening and has effects we haven't thought of," says Ben Winger, an ornithologist（鸟类专家）at the University of Michigan, who wasn't involved in the research but has documented similar shrinkage（缩水）in migratory birds.

To see if non-migratory birds have also been shrinking, Jirinec and colleagues analyzed data collected from 1979 to 2019 in a remote region in the Amazon that spans 43km. The data include over 11,000 individual birds of 77 species as well as climate for the region.

All species declined in mass over this period, the researchers found. Species lost from about 0.1% to nearly 2% of their average body weight each decade. The motmot, for example, shrunk from 133g to about 127g over the study period.

These changes coincided with an overall increase in the average temperature of 1℃ in the wet season and 1.65%℃ in the dry season. Birds' mass decreased the most in a year or two after especially hot and dry seasons, which tracks with the idea that birds are getting smaller to deal with heat stress.

Wing length also grew for 61 species, with a maximum increase of 1% per decade. Jirinec thinks longer wings make for more efficient, and thus cooler, fliers.

"The Amazon rainforest is mysterious, remote and full of biodiversity," Jirined says. "This study suggests that even in places like this, far removed from civilization, you can see signatures of climate change."