In the world of water, 2021 was another year for the record books. Parts of Western Europe suffered from deadly floods while large areas of the southwestern United States remained locked in a massive drought.

One might think that our impressive water management would safeguard society from such catastrophic events. Yet when it comes to water, the past is no longer a good guide for the future and most of the water engineering is unprepared for consequences of increasingly occurring extreme weather. One of the most alarming wake-up calls came from the city of Cape Town, where the water taps of 4 million residents were nearly forced to be shut off after severe drought dried up its reservoir (水库).

Appealing as it might be, the solution is not to further build bigger and higher dams (水坝) that often result in more disastrous flooding. Rather, it is to work more with natural processes.

The Netherlands avoided major damage from the historic floods in July 2021 thanks to its recently completed project, which gives river room to spread out by redirecting floodwaters into wetlands, lowering parts of the stormy river by more than a foot. Agricultural practices offer another strategy. Scientists have found that boosting organic matter in the soil by 1% can increase the soil's water-holding capacity by up to 18,000 gallons per acre, creating flexibility to both intense rains and dry periods. This means farmland practices such as the planting of cover crops can not only raise output but improve water management.

Solutions don't come easily, but they are key to a livable future. While it's too late to avoid the impacts of climate change, we can avoid the worst of those impacts by investing more in such nature-based water solutions. 

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. 

Efforts to preserve the Amazon rain forest, which supports immense biodiversity and locks away tons of climate threatening carbon, are growing more urgent as the ecosystem's destruction accelerates. Indigenous (当地的) peoples have been trying to protect the region by patrolling(巡逻) their territorial boundaries for illegal activities. But rapid deforestation continues.

A recent study shows that combining on-the-ground monitoring with satellite data and smartphone technology could help put the brakes on Amazon deforestation—and potentially that of forests elsewhere.

Illegal logging, agriculture and coca cultivation particularly threaten the Amazon in the Peruvian Indigenous communities and outsiders are often the culprits (罪魁祸首). The research team wondered if providing training for local people to use satellite-based "early deforestation alerts" could help. The scientists collaborated with 76 Indigenous communities, 36 of which participated in using these alerts to watch over the forest. Over the next two years these trained participants were paid to work as forest monitors and received monthly alerts via the app when satellite data indicated local forest losses. Monitors investigated alerts, patrolled for deforestation in other areas and reported confirmed losses back to their communities, which decided whether to deal with the culprits on their own or inform state authorities.

The researchers analyzed the same forest-loss satellite data from the given time period in all 76 communities. They found the early-alert program reduced forest loss by 8.4 hectares in the first two year—a 52% reduction compared with the average loss in the control communities.

Experts say this approach to tackling Amazonian deforestation looks promising. "Would this work in all communities that have high risk of deforestation? Given the results, it's worth a try." says Catherine Tucker, a researcher at the University of Florida. "But some communities may not have access to the resources needed for such a program, or their territories may hold valuable minerals that would increase the risk of deforestation by outsiders despite monitoring efforts," wrote Francisco Hernandez Cayetano, a community member involved in the research, "we as Indigenous peoples ask the world for support."