5 . A “fierce queen” named “128 Grazer” has been crowned the fattest bear of all of Katmai National Park in Alaska. Grazer, a mama bear to two litters of cubs(幼兽), has been a fixture(固定成员) of the park since 2005.

This is Grazer’s first time winning the contest, an achievement made easier by the fact that she has released her cubs and was able to focus on self-care. When females are caring for cubs, they are often nursing them, helping them hunt for salmon(三文鱼) and providing them protection — all of which detracts from the females’ ability to eat as much as possible, said Felicia Jimenez, a ranger at Katmai National Park.

The brown bears living along Alaska’s Brooks River have spent the summer fattening up on salmon, berries and grasses in preparation for their annual winter hibernation(冬眠). The bears enter hibernation around November and eventually experience a one-third loss of their body weight through the winter season, according to park officials.

The fixed competition has been making the fattest brown bears at Katmai National Park compete against each other since 2014. When the contest first began, it consisted of just a single day in which a few of the park’s most enormous bears competed with each other. By the next year, the contest had transformed into a “globally recognized” event that required more days and more competitors.

The popularity of Fat Bear Week allows park officials to direct attention to conservation efforts in the region, especially for the salmon run on the Brooks River, which the bears rely on for food. The health of the brown bears signifies the overall health of the local ecosystem, according to the park. “Without the ecosystem protected, there would be no Fat Bear Week,” Jimenez said.

7 . After most people complete their undergraduate degree, they either take a break or jump into a job. Few, like Brianna Craft, set out to save the world.

It started when she was a freshman sitting in an environmental studies class in 2006. Craft was shocked when the professor described the harm climate change was having on people. She records the moment in her new book, Everything That Rises: A Climate Change Memoir.

After graduation, Craft spent a year in AmeriCorps, focusing on protecting the environment. AmeriCorps is an organization connecting individuals and organizations to help communities tackle their toughest challenges. “That helped me figure out that my future was not in doing science,” she says. Instead, she wanted to work with people and policy.

She then had an opportunity to attend the UN climate negotiations (磋商). That, in turn, prepared her for her current role as a senior researcher at the London-based International Institute for Environment and Development (IIED). Her focus is to ensure that the lowest contributors to greenhouse gases and those most affected by climate change have a voice in international climate negotiations.

For five years, Craft attended and supported climate conferences around the world, leading to the signing of the Paris Agreement in 2015. Craft says, “I wanted people to care about the work I did in the climate negotiations, and why we pushed so hard to form this agreement.” That led her to write Everything That Rises: A Climate Change Memoir.

Craft brings the viewpoint of an African American woman from a rural northwest community. She weaves (编织) together several storylines-including her difficult childhood with an irresponsible parent, her self-discovery in college and her work to help work towards climate agreements and ensure that even the smallest countries have a voice.

8 . Scientists have been able to track the entire life of a mammoth (猛犸象) that lived more than 17,000 years ago. The team figured out where in Alaska it likely was at any given point of its 28-year life.

To do so, the researchers closely studied a 1.8-meter-long mammoth tusk (象牙) dating back around 17,100 years. Mammoth tusks grow by adding layers of tissue almost daily, forming rings like a tree that can reveal detailed information.

The main thing the researchers analyzed was strontium isotopes (锶同位素), which can act almost like an ancient GPS. Different areas have different isotopic features, which start in minerals deep underground and make their way to the top of the land, into plants and water. Finally, they can be seen on the animals that consume those plants and water.

Previous studies had produced an isotopic map of Alaska by analyzing isotopes in the teeth of hundreds of small animals, which don’t travel far in their lifetimes and so represent a local area. The researchers can then compare isotopic signals from each part of the mammoth’s tusk to this map, to get an idea of where the mammoth most likely wandered throughout its life.

The scientists started from where its remains were found. Working backwards, the scientists then looked at the isotopic feature of where the mammoth was about a week before death, then searched the map for the best match in a nearby area. A model then worked backwards stepwise to determine the most likely routes the mammoth might have taken.

According to the research, the mammoth seems to have spent his early years in the Yukon River Basin and Alaska, constantly trekking between several territories in a predictable pattern. The team says that this behavior seems to be like modern elephants, moving regularly from place to place.

9 . Plastic is everywhere in our modern world. Its toughness makes it an extremely useful material from household items to vehicle parts, but that same toughness makes it hard to break down for recycling or disposal (处理). However, Japanese scientists at the University of Tokyo have developed a new plastic material that can be broken down more easily and can self-heal and remember past shapes.

Based on a kind of plastic called an epoxy resin vitrimer, which is brittle (脆性的), the new plastic boasts a huge range of advantages. Once scratched with a knife, it can completely patch itself up after being heated to 150 ℃ for just 60 seconds. When shaped into the shape of a crane, then flattened, it can fold itself back into the crane shape by being heated up. It does all of this much faster than others of its type.

The new plastic can also break down easier. Even if it’s discarded (丢弃) into the environment, it still poses less of a, problem than other kinds of plastic, which the team demonstrated by placing it in seawater for 30 days. It biodegraded by 25% and released molecules (分子) that are essential food for marine life.

The new plastic is more resistant to breaking. It can also repair itself, and can recover its original memorized shape. It even biodegrades safely in a marine environment, according to Shota Ando, a researcher of the study.

The material can be used in a variety of applications, “Infrastructure materials for roads and bridges are often composed of epoxy resins mixed with compounds such as concrete and carbon,” said Ando. “By using the new plastic, these would be easier to maintain as they would be stronger and healable using heat. Unlike conventional epoxy resins, this new material is hard but stretchable, so it could also be expected to strongly bond materials of different hardness and stretch.”

10 . Landscape architect Kotchakorn Voraakhom has designed a new green roof on the Rangsit Campus of Thammasat University, about 25 miles north of central Bangkok, Thailand. Her imaginative work challenges the common thinking that urbanization has a negative impact on the planet, whether flooding, excess (过度的) energy use, disrupted (扰乱) biodiversity or the heat island effect.

The 236, 806-square-foot structure, which opened in December 2019, includes a flood water management system and Asia’s largest rooftop organic farm. It combines modern landscape architecture with traditional agricultural knowledge, creating a green and friendly environment.

The green roof, containing an H-shaped landscape, looks like a futuristic hill with a brick building beneath it. The hill features a complex pattern of zigzagging terraces (之字形梯田) of planted beds, leading all the way down to the bottom. When rainwater hits the roof, it flows down the zigzags while being absorbed by the soil in the beds, The excess water is directed into four storage ponds — with a capacity of up to 3 million gallons. The process slows down the flow speed of rainwater runoff compared to a normal concrete rooftop. This keeps the area from flooding during heavy rains.

The roof’s terraces are filled with organically grown crops, including a drought tolerant variety of rice, many local vegetables and herbs. The farm can supply the canteens on campus with a large amount of rice, herbs and vegetables a year. The food waste is composted (把……制成堆肥) to fertilize the farm, and water from the storage ponds is used to water plants, creating an entirely localized and circular system.

The farm serves as an outdoor classroom and a source of local jobs, too. Farmers offer workshops on sustainable agriculture and nutrition as part of the university’s sustainability curriculum. “Students and community members are invited to participate in seasonal seeding, harvesting, and so on,” says Voraakhom. “The urban farm is training a new generation of organic farmers with real-world skills. It also promotes a sense of community.”