4 . For years scientists have been worried about the effects of air pollution on the earth’s natural conditions. Some believe the air inside many houses may be more dangerous than the air outside.

Most scientists agree that every modern house has some kind of indoor pollution. People began to notice the problem in the early 1970s. When builders began making houses and offices, they did not want to waste energy. To do this they built buildings that limited the flow of air between inside and outside. They also used man — made building materials which are now known to let out harmful gases.

As the problem became more serious, scientists began searching for a way to deal with it. They discovered a natural pollution control system for building green plants.

Scientists believe that a plant’s leaves absorb the pollutants (污染物). In exchange the plant lets out oxygen through its leaves. Studies of different plants show that each absorbs different chemicals. So the most effective way to clean the air is to use different kinds of plants.

Preserving more habitats for China’s giant pandas is providing a giant payoff.     1     (save) the giant panda from dying out isn’t just good for the panda, but it’s also good for economy, a new analysis by an international team of scientists shows.

The results     2     (publish) in the magazine Current Biology, stress the economic benefits that go hand in hand with environmental     3     (protect). Giant pandas are one of the rarest species around the world. But pandas fell on hard times in recent decades, thanks largely     4     human encroachment (侵入). In 1980 alone, many habitats     5     (destroy) artificially, and in 1990, their habitats covered only 12,340 square kilometers, which is a major threat to the pandas in large part because bamboo, their main food source, is so low in nutrients     6     they must wander a lot of land in order to find and eat enough of it.

Because of this, Chinese officials began making     7     (significance) efforts to save the panda from extinction, establishing more reserves and increasing the reserve area three times. Panda numbers     8     (gradual) began to recover, hitting 1,596 in 2000 and 1,864 in 2010.

“    9     is clear that society’s investment (投资)     10     (start) to pay off so far in terms of panda population recovery”, the study authors said.

6 . A flood hit Yellowstone National Park on June 13, 2022. The disaster was caused by a combination of unusually heavy rain and rapid snow melt. The high and fast water flows destroyed bridges and swept away entire roadways, leaving communities and homes isolated (隔绝的). Fortunately, the approximately 10,000 park visitors were safely evacuated.

The town of Gardiner, along the Montana-Wyoming border, was particularly hard hit. The floodwaters left almost 900 people with no power or water for many days. Gardiner’s economy, which heavily depends on the almost three-quarters of a million visitors who pass through the park’s north gate annually, is likely to take a hit. The floodwaters severely damaged the main north entrance road to Yellowstone and could take years to rebuild.

Park officials have begun work on improving an alternative road to Gardiner. This will ensure that locals can access food, supplies, and other essential emergency services. A limited number of tourists may also be allowed into Gardiner once the road is stable.

Yellowstone’s north gate is closed indefinitely (无限期地). But the park’s south gate opened to visitors on June 22, 2022. Park officials have started a new entry system to prevent overcrowding. It is based on the last number of the visitor’s vehicle license plate and the calendar date of the month. Cars with odd numbers can visit the park on odd days of the month, while those with even numbers can go on even days.

Established in 1872, Yellowstone is America’s oldest national park. The 3,472-square-mile reserve spans three states and is home to a lot of unique wildlife. It is known for its natural beauty that includes mountains, rivers and lakes. The forces of fire and ice shaped the park over thousands of years.

7 . Soot (煤) pollution is speeding up climate-driven melting in Antarctica, a new study suggests, raising questions about how to protect the delicate continent from the increasing number of humans who want to visit.

“It really makes us question, is our presence really needed?” says Alia Khan, one of the authors of the new study. “We have quite a large black carbon footprint in Antarctica, which is enhancing snow and ice melt.”

Black carbon is the leftover thing from burning plants or fossil fuels. Soot in Antarctica comes primarily from waste gases of cruise ships (游轮), vehicles and airplanes, although some pollution travels on the wind from other parts of the globe. The dark particles (微粒) coat white snow and absorb heat from the sun the way a black T-shirt does on a warm day. The blanket of dark bits speeds up melting that was already happening more quickly because of global warming.

When snow and ice are uncovered, they reflect an enormous amount of sunlight before it can turn into heat. “These are the mirrors on our planet,” says Sonia Nagorski, a scientist at the University of Alaska Southeast. “When those mirrors are covered in a film of dark bits, they don’t send back that much light and heat. That means more heat is trapped on Earth, speeding up melting and contributing to global warming.”

As a scientist who personally visits Antarctica every year, Khan says she is troubled by her own research results. On the one hand, she goes to Antarctica to collect crucial data about how quickly the snow and ice there are disappearing. “But then when we come to conclusions like this it really does make us think twice about how frequently we need to visit the continent,” she says, “and what kind of regulations should be placed on tourism as well.” That could mean requiring that cruise ships and vehicles be electric, for example, or limiting the number of visitors each year.

10 . A team led by researchers from the UK examined waterbird data from 1506 protected areas and analyzed more than 27, 000 bird populations across the world. They compared waterbird populations before and after the establishment of protected areas and also compared trends of similar populations within and outside of protected areas.

“Our study shows that, while many protected areas are working well, many others are failing to have a positive effect, ” lead author Hannah Wauchope says in a statement. “In the majority of places we looked, bird populations were stable or were increasing, but some of them weren’t doing any better than in unprotected areas, “ she adds. “That’s disappointing, but not surprising. There seems to be the disconnection between people talking about how much land is protected and whether those areas are actually doing anything positive. ”

This study comes ahead of a United Nations meeting in China to discuss biodiversity goals for the next decade. Several countries have already committed to protecting 30 percent of the planet by 2030, yet the researchers say this alone does not necessarily guarantee positive out- comes for species.

“An obsession(迷恋)with reaching a certain area-based target-such as 30 percent by 2030-without focus on managing existing protected areas appropriately will achieve little, ” co-author Julia Jones says. “When world leaders gather in China later this year to set targets for the next decade, I really hope to see a change of their focus, rather than simply saying how much surface area they are going to protect. ”

According to Thomas Brooks, chief scientist at the International Union for Conservation of Nature, who was not involved in the study, waterbirds are a good example of a group facing the consequences of human behaviors that cause biodiversity loss. These animals respond quickly to changes in site quality and are broadly distributed, clearly reflecting the impact of protected areas.