1 . People have come to understand the enormous impacts-beneficial as well as harmful- plastics have on human lives and the environment. As polymer (聚合物) scientists committed to inventing sustainable solutions for real-world problems, we set out to tackle the issue of plastic waste by rethinking the way polymers are designed so we could make plastics with recyclability built right in.

Everyday items including milk jug, grocery bags, and takeout containers are made from a class of polymers called polyolefins. These plastics are really durable (耐用的) because the chemical bonds in those polymers are extremely stable. In a world set up for disposable (一次性的) items, durability is no longer a design feature but rather a design drawback. Imagine if half the plastics used today were recyclable through twice as many processes as they are now. Also conventional recycling requires careful sorting of all the collected materials, which can be challenging with so many different plastics. For example, separating paper from metal doesn’t require complex technology, but sorting a container from a milk jug of a different polyolefin is difficult to do without the occasional mistake.

In a study published in Science in October 2023, we described a series of polymers with only two building blocks-one soft polymer and one hard polymer-that behave like polyolefins but could be chemically recycled. Connecting two different polymers multiple times until they form a single, long molecule (分子) creates what’s called a multiblock polymer. By changing how much of each polymer type goes into the multiblock polymer, our team produced a wide range of materials with properties that covered all polyolefin types.

Using the same strategy but by adding hydrogen, we could disconnect the polymers back into their building blocks and easily separate them to use again. When we made new polymers out of these recycled plastics, they performed just as well as the original materials even after several rounds of chemical recycling. So we were able to create materials with similar properties of the plastics the world relies on. We believe this work is a step toward more sustainable plastics.

2 . Anuar Abdullah is a 61-year-old diving instructor in Malaysia. When he isn’t ________ he’s back out in the water ________, studying, and restoring coral reefs (珊瑚礁).

Now, as climate change becomes an ________ threat, governments, corporations, and others are coming to him for ________.

Abdullah has no degree in marine biology or ________ training — just an amount of experience. In just the past decade, thousands have ________ to him to learn how to grow corals, and he now has around 700 volunteers ________ and has already restored hundreds of acres of coral reefs.

In 2017, Thailand’s government asked Abdullah to ________ the recovery of one of its most famous tourist attractions, Maya Bay, because it had ________ half its coral population. ________ were kept out of the site for three years while Abdullah led a team of 120 people in ________ new corals.

In 2021, after Typhoon Rai, the island of Cebu in the Philippines asked Abdullah to save what was ________ of the shoreline’s coral reefs. And earlier this year, Abdullah launched a new effort to build the world’s largest coral nursery in the Red Sea. There was a ________ on the nursery at the U.N. climate change summit (峰会), COP27, but Abdullah did not attend. He ________ conferences, he says. And he had ________ to do.

3 . While it throws out about 90 pounds of food per person every year, Japan doesn’t rank at the top of the world’s list of wasteful nations. Still, what’s thrown away represents a serious problem for an island nation with limited landfill space and a goal of greater sustainability. Reinvention can offer an alternative. A Japanese company is taking vegetable peels, cooking oil and other used foodstuffs and making entirely different products.

Concrete is the most widely used construction material in the world, and its key element, cement, is a major polluter of greenhouse emissions. So what if a more sustainable alterative were possible by making cement with food waste, which also would help reduce greenhouse emissions from landfills where that waste would otherwise be thrown away? That’s the idea behind Fabula, a Tokyo-based start-up.

Researchers at Fabula created a recipe to make food concrete by drying leftovers and pressing them into a mold (模具) at a high temperature. The company, founded by researchers at the University of Tokyo, began with items commonly thrown away like cabbage and orange peels but found that almost any food item can be used. It now takes mostly coffee grounds and tea leaves to make its cement. The product’s durability depends on the components.

Fabula is currently producing made-to-order household items, such as coasters and dishes, while awaiting its patent. The goal is to make furniture and larger structures once the technology is able to make the cement more durable. Food production companies that can’t avoid generating waste during their processes have reached out to work with the company. “We hope to become a matching service between companies that have food waste and companies who want to build things out of such materials,” said Takuma Oishi, Fabula’s chief commercial officer.

Since the cement is 100 percent eatable, it could create opportunities during disaster response when temporary structures need to be built quickly. The people inside might even turn to them for food. If the technology advances enough, Oishi suggested, someday we may be able “to eat the homes or furniture when necessary”.

4 . 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.

5 . Every year, as the surface water temperature off the United States mid-Atlantic coast rises steadily from late spring through the summer, a pocket of uncharacteristically cool and crisp water gets trapped at the bottom of the ocean. Packed with nutrients this thick band of cold water, known as the mid-Atlantic cold pool, is a vital home for shellfish species. Extending at its seasonal peak from Nantucket, Massachusetts, to Cape Hatteras, North Carolina, the cold poll creates a diverse ecosystem ranging from algae(海藻)to fish — and some of the most valuable shellfish fisheries in the United States.

Now, however, two pressures have scientists worrying about whether the cold pool will last. The first is no surprise: climate change. Over the past five decades, climates change has destabilized the cold pool, causing it to warm and shrink. Compared with 1968, the cold pool is now 13℃ warmer and has lost more than one-third of its area.

The second concern is 1ess certain. In 2023, the US federal government approved plans to install(安装)98 wind turbines(涡轮机)off the New Jersey coast, covering an area of more than 300 square kilometers. Yet putting so many turbines to the seafloor could have unexpected consequences for the cold pool. That’s why Travis Miles, a researcher at New Jersey’s Rutgers University, and his colleagues are investigating. So far, Miles and his colleagues can’t definitively say what will happen to the cold pool, saying more research is needed to assess how climate change and offshore wind, together, could affect the cold pool. However, their initial analyses suggest the cold pool should be fine — at least in normal conditions.

New Jersey’s offshore wind plans are strongly opposed mainly by fossil fuel-industry funded efforts. Miles worries that an overabundance of caution or fear of potential impacts, including on the cold pool, might slow down the development of renewable energy. “...it’s quite clear that climate change is far more damaging than installing wind farms,” he says. “I don’t think any scientist would argue with that.”

6 . Traditionally, profiting from forests often meant capitalizing on timber (木材)——choosing commercial timber. Yet increasingly, there is an understanding that it’s of greater significance to keep trees standing than cut them down for financial profit. Money is not everything. We have to recognize real and lasting value is from natural resources. But money is a fact of life.

Good news is that we can expect entire natural woodland is left undamaged and still provides a revenue (收益) stream. Leaving woodland complete does not necessarily mean that we do not touch it at all. Conservation work may involve building back biodiversity or the removal of foreign plant species.

A healthy woodland system can provide a range of yields (产物). Besides eatable yields——top fruit, berries, and food crops, it produces substances for chemical use. The non-timber forest products provided by natural ecosystems will vary significantly depending on where they are. But there’re almost always ways to explore to acquire revenue.

A project in the U.K. shows woodland is also a draw for visitors. It engages a community who creates a sustainable area of woodland. The sale of handmade wooden items and non-timber forest products is involved. But the community largely obtains revenue by opening up parts of the natural woodland to the public with an adventure playground and outdoor recreational activities on the site. It also offers courses on nest building, special wildlife events and more. The project is thought to have great uniqueness. In terms of revenue, it centers round the existing natural land; the yields woodland can provide become side products.

Recreational activities, tours, and classes are just the commencement. A rich and biodiverse woodland can be an ecosystem that draws in people looking for a beautiful place to stay. Woodland has great value in ecological and social terms. And when you nurse it, it could also add to the income from your land.

7 . In 2014, Xu Yitang, a student at the National Academy of Chinese Theatre Arts, saw corals at an aquarium for the first time.

Little did he know the chance ______ with the creature would spark a lifelong ______. He began to ______ the local market to learn about coral farming from merchants selling plants, fish and corals. He also searched for information on relevant forums online, and before long, started ______ a coral in a small fish tank at home.

“The coral organism is quite ______ and has extremely high ______ for water quality,” recalls Xu. “In the beginning, its state was not good.”

As he became better ______ of the creature, he learned that coral reefs are known as “tropical rainforests” and “underwater gardens” of the ocean, providing ______ for a quarter of all marine life. ______, rising sea temperatures have led to coral ______. Xu felt an increasing sense of urgency and ______ to protect them.

Fast-forward to today, he ______ a coral conservationist in a Sanya-based tropical biological research center.

Each day, he spends several hours diving deep under the waves to observe and ______ the growth and development of the creatures.

His story has been ______ in the recently premiered online program Burning Youth that aims to use documentary shorts and in-depth studio interviews to ______ the inspiring stories of young Chinese people from various walks of life.

10 . From airplanes to apartments, most spaces are now designed with sound-absorbing materials that help decrease various sounds of everyday life. But most of the sound-absorbing materials that can cancel out human voices, traffic noise and music are made from plastic foams (泡沫) that aren’t easily recycled or degraded. Now, researchers reporting in ACS Sustainable Chemistry & Engineering have created a biodegradable film (薄膜) obtained from seaweed, which effectively absorbs sounds in this range.

Controlling and optimizing the way sound moves throughout a room is the key to creating functional spaces. Foam sound-absorbing panels are a common solution, and they come in a variety of materials and thicknesses tailored to specific sound requirements. Most of these foams, however, are made from a type of plastic material and other chemical substances that are obtained from natural oil or petrol. To avoid petrochemicals, researchers have explored more renewable sources and biodegradable sound-absorbing alternatives. But many current options are made from plant fibers that don’t effectively decrease noises in the most useful range of sound frequencies, or they are too thick or difficult to produce. So, Chindam’s team wanted to develop a biodegradable material from a plant, which would be simple to produce and could absorb a range of sounds.

The team created films of agar (琼脂), a material that comes from seaweed, along with other additives developed from plants and varied the thickness of the films. After running the materials through a battery of tests, the researchers measured how well the films reduced sound across a range of frequencies. To do this, the team created a sound tube in which a speaker is placed at one end, and the test film is fitted over the other end. Microphones in the middle of the tube measured the amount of sound sent by the speaker and the amount of sound reflected off the film. These experiments showed that the films with many small holes made with the highest concentrations of agar had the greatest sound-absorbing qualities and performed similarly to traditional sound-absorbing foams. The researchers plan to explore ways to change the agar films to give them other desirable properties, such as flame resistance, and will explore other biologically obtained film materials.