1 . Since the Endangered Species Act (ESA) was passed in 1973, it has helped hundreds of species avoid extinction in the United States. The strong conservation policy has been used as a model in other countries. But it’s not as successful as it could be, a new study finds.

Researchers have discovered most species are not being protected until their numbers have become so low that their chance of recovery is slim.

“The ESA is an incredibly powerful, ambitious law for protecting our endangered wildlife. Yet, for decades, the agency primarily responsible for operating the ESA — the US Fish and Wildlife Service (USFWS) — has been starved of resources,” lead author Erich Eberhard says.

“As a result, we are very slow to give species the protection that they deserve. We typically wait until species are extremely rare and thus at extreme risk of extinction, and then, when a species is finally listed, the USFWS is straining its resources to try to recover it.”

In 1993, a study found that few species received protection under the ESA until their populations became very small. For the new study, researchers repeated the methods used in the earlier research to see whether protections have become better since the problem was first noted. They also looked at trends in “wait times” — the amount of time between when a species is identified as potentially needing protection and when it actually receives protection under the ESA.

“Our analysis suggests that, in the nearly 30 years since attention was first brought to this problem, we have not become more active in protecting endangered species,” says Eberhard.

The researchers found that the population sizes of species when they first became protected under the ESA are not statistically different from those in the 1993 study. They also discovered that there are long wait times between when a species is identified as likely needing protection and when they actually receive them.

“I can say that our study paints the current state of the ESA as a bit of cautionary (告诫的) tale for the strong conservation policy,” says Eberhard.

2 . High-resolution (高分辨率) satellite imagery has been used to map every single tree in Africa, showing a technique that could help improve the monitoring of deforestation (森林砍伐) across the world. Florian Reiner at the University of Copenhagen, Denmark, and his colleagues used images from sate lies to map canopy (树冠) across the entire African continent.

Modern sate lies usually catch tree canopies at a resolution of 30 meters — fine for measuring the size of forests, but less good at mapping individual trees. The satellite data Reiner and his colleagues used had a resolution of 3 meters, enabling the study to map all trees, including those not part of a forest.

The results suggest that 30 percent of all trees in Africa aren’t in a forest and instead are across farmland, savannah and urban areas. “Many countries in Africa lack thick forests, but have a lot of trees.” says Reiner. “These trees are extremely important to the local ecosystems, the people and the economy. By tracking every single tree, researchers can start to monitor how these trees are coping with climate change or whether they are sensitive to deforestation.” It could also improve the monitoring of reforestation efforts, which are growing in popularity as a way of removing carbon dioxide from the atmosphere.

“At a local level, being able to consistently monitor when and where trees are disappearing or reappearing can lead to more actionable insights,” says John Francis at the Alan Turing Institute in London.

“The study is a proof of concept rather than a map ready for immediate commercial use,” says Reiner. “It’s research work. It’s showing what could be done,” he says. But he is already working with colleagues to scale up the tracking approach to cover the entire global canopy: “We’re hoping that this will be seen as a way forward in monitoring tree resources.”

4 . In 2019, Gotham Greens opened its 9,300-square-metre Baltimore farm on the former site of Bethlehem Steel, which was the largest steel-manufacturing plant in the world.     1     It aimed to repurpose unused rooftop spaces and abandoned factories for food production.

Urban populations are projected to increase by 2. 5 billion by 2050.     2     But despite the rise in city-based farms, there’s still a lot we don’t know about them, including the economic and environmental costs.

Florian Payen, an environmental scientist, and his colleagues looked at previous studies done in 53 countries where crops were grown in different urban environments, including “grey” spaces such as rooftops, and by using different growing methods. They found that yields(产量) of urban crops were often the same as those from conventional farms. Just as importantly, they revealed the most commonly-grown types of crops and the most effective growing methods.     3    

It’s known that the benefit of urban farming is a reduction in food miles.     4     In one study, researchers analyzed the carbon footprint of different vegetables grown in greenhouses in Canada and that of the importing vegetables from the USA. “They found that it was less carbon-intensive to import the crops because of the high energy input required to grow them locally in greenhouses,” says Payen.

    5    Urban agriculture has the potential to enhance local ecosystems, attracting pollinators (传粉媒介) such as bees and birds that boost urban biodiversity while providing more green spaces to help keep cities cool and counter the urban heat island effect.

5 . Heat waves are becoming more common in parts of the United States — and that means more people running their air conditioners for longer. But those air conditioners can make the problem worse, giving off greenhouse gases as they work that contribute heavily to climate change.

SkyCool Systems is trying to break that cycle, using technology that promises to offer buildings an alternative means to cool down in a similar way to how the planet cools itself. “Our planet naturally cools itself by sending heat out in the form of infrared light (红外线) or radiation,” said Eli Goldstein, SkyCool’s cofounder and CEO. “We do this through rooftop panels, which look like solar panels but actually do the opposite, reflecting 97% of the sunlight that hits them and cooling the surface below,” said Goldstein.

SkyCool’s model involves fixing a network of pipes below those panels. These pipes are filled with water, which is kept cool by the panels and then flows into an air conditioning system. This process is designed to take pressure off the system’s cooling mechanism. And because the panels cool naturally and don’t need external power to function, it helps the entire system use less electricity.

A Grocery Outlet store in California, which has been using SkyCool’s system since last year, says it saw a marked drop in its electrical bills. Jesus Valenzuela, the store manager, estimates that the panels have saved his store roughly $3,000 a month.

But perhaps the biggest barrier to making the technology ubiquitous (无处不在的) is its relatively high cost. Increasing production could help bring the cost down, Goldstein said, particularly for developing countries in Asia and Africa where SkyCool hopes to eventually expand. For now, the company is focused on commercial applications of the technology, though it hopes to start setting up panels on the roofs of individual homes. “We’re just excited to be able to use this new technology for good,” Goldstein said.

7 . Sometimes, when we talk to our dogs, they tilt (倾斜) their heads adorably to one side. Although it might suggest disbelief or confusion, the gesture could actually be a sign of concentration, according to a new study.

Researchers investigated how well 40 dogs of various species could memorize the names of different toys and then recall that information in order to retrieve (找回) specific toys in response to their owners’ commands. Most of the dogs weren’t able to learn the toy names, but seven (one died during the study) border collies (边境牧羊犬) showed extraordinary ability to do the job.

The scientists regarded that group as “gifted word learners”, and found that the seven collies had something in common: they all tilted their heads far more frequently than other dogs after hearing a command. The data showed that the gifted learners tilted their heads 43 percent of the time, while the other 33 dogs did the gesture just 2 percent of the time. “It seems that there’s a relationship between the success in retrieving a specific toy and frequent head tilts upon hearing its name,” said Shany Dror, an animal researcher at Eötvös Loránd University in Hungary.

The gifted dogs showed they could learn 12 new toy names in one week, and then remember those names for at least two months. And only the gifted dogs who performed well at the toy retrieval tests consistently tilted their heads after hearing a command. That led Dror’s team to conclude that the gesture is related to collies’ attempts to work out the meaning of a word.

Similar to the way humans are right- or left-handed, the gifted collies also tended to move their heads to just one side or the other. Their favored side stayed the same during the three experiments regardless of where the owners were standing. To the researchers, that consistency may be additional evidence that dogs tilt their heads when paying close attention to a test.

The so called “right-tilters” and “left-tilters” may be individual preference, which scientists want to investigate further.

9 . When Malaika Vaz was a kid, living in Goa, India, she was constantly surrounded by nature. Among her childhood experiences, she recalls journeys to the Arctic and Antarctic, climbing mountains, diving, and windsurfing.

At some point in her late teens, Vaz realized adventure didn’t really mean anything if there wasn’t an intention to protect the natural spaces we were exploring in. Motivated by her passion for filmmaking, she began to seek a way that would both satisfy her appetite for adventure and allow her to advocate the protection of the species and ecosystems she interacted with.

Today Vaz wears many hats in the filmmaking world, as a documentary director, producer, and presenter. After falling in love with manta rays (蝠鲼), she discovered they were being hunted illegally and started to dress herself as a seafood trader to get as close as possible to the issue. She traced sellers to figure out why the threatened species were being killed. She shared the shocking details in Peng Yu Sai, her Green Oscar-nominated film on the matter.

The subjects that grab her attention, Vaz admits, run the gamut. When she was asked to define her focus, she replied that she preferred variety. She always argues that the issues she looks into are more interrelated than they may initially appear. “I think that it’s exciting to dive into the different aspects of environmental stories,” she says.

Her work doesn’t stop at recording important stories; she also ensures the message is heard. From Vaz’s viewpoint, real improvement in planetary protection lies in the hands of each of us rather than just those of several environmentalists. “If you’re an engineer and you care about the natural world, you can change the kind of construction materials you use. If you’re a teacher loving nature, you can bring that into the learning for your class.” she says.

As a filmmaker, Vaz believes it’s important to figure out ways that attract the audience who can push for the protection of the natural world.