【推荐2】Natural silence — the kind when you hear nothing but the sound of nature around you — is becoming increasingly scarce. The noise of man-made can be heard even in the remote corners of national parks and deep in the Arctic Ocean.

This is having some troubling effects. In humans, noise pollution has been linked to physical, mental health problems and cognitive impairment (认知功能障碍) in children. In wildlife,it’s disturbing navigation, pairing, communication and can cause hearing loss. “We’re losing the ability to listen to nature without noise pollution,” says sound recordist Matt Mikkelsen. He’s part of the non-profit organization Quiet Parks International, which aims to identify and preserve the planet’s last quiet places.

Recently, this took him to Boundary Waters Canoe Area Wilderness in northeastern Minnesota. No cars, motor boats, electricity or telephone lines are allowed in the one-million-acre area,making it a strong candidate for Quiet Park status. But listening back to the recording, Mikkelsen can hear the low hum (嗡鸣声) of a commercial plane flying far away.

Quiet Parks hasn’t yet decided if Boundary Waters meets its criteria — it’s one of 260 potential sites around the world that the organization is currently exploring. The team will analyze the sound recordings from each location and consider them alongside other data.

In recent years, the world has been getting louder, with cities and towns expanding and an increasing number of noises from cars, airplanes or ships. But during the COVID-19 pandemic (流行病), there has been momentary delay.In2020,global air travel was down by 60% and road transport decreased by almost half. Scientists in Europe found that noise caused by humans fell by up to 50% after lock downs were carried out.

“People enjoyed the silence,” says Mikkelsen. “There were no airplanes in the sky and cars weren’t on the street. It was an incredible thing to be able to hear the world, all of a sudden, free from noise pollution,” he says. Since the start of the pandemic, Quiet Parks says it has experienced a huge increase in interest for quiet places. “I hope that we can take that desire for a world with less noise forward,” says Mikkelsen, “and appreciate the spots we have, where we can go and not experience noise pollution.”

【推荐3】Research shows people have a tendency to seek out information during uncertain times — it’s a natural coping mechanism (机制). But is continuous information-seeking on social media, sometimes called doomscrolling (末日刷刷刷), helpful during a pandemic, or any time?

Research on the effects of bad news on mood suggests exposure to negative COVID news is likely to be dangerous to our emotional well being. For instance, one study conducted in March 2020 involving more than 6,000 Americans found that the more time participants spent consuming COVID news in a day, the unhappier they felt.

These findings are striking but leave a few key questions unanswered. Does doomscrolling make people unhappy, or are unhappy people just more likely to doomscroll? How much time spent doomscrolling is a problem? And what would happen if, instead of doomscrolling, we were “ kindness scrolling ” — reading about humanity’s positive responses to a global crisis?

To find out answers to these questions, researchers conducted a study where they showed hundreds of people real-world content on either Twitter or YouTube for two to four minutes. The Twitter feeds and YouTube videos featured either general news about the COVID, or news about kindness during COVID. Researchers then measured these participants’ moods using a questionnaire, and compared their moods with participants who did not engage with any content at all.

People who were shown general COVID-related news experienced lower moods than people who were shown nothing at all. Meanwhile, people who were shown COVID news stories involving acts of kindness didn’t experience the same decline in mood, but also didn’t gain the boost in mood they’ d predicted. These findings suggest that spending as little as two to four minutes consuming negative news about COVID-19 can have a negative impact on our mood.

Researchers are still working on what people can do to look after themselves, and make time on social media more pleasurable.

【推荐1】In just a few decades the United States could eliminate fossil fuels（矿物燃料）and rely 100 percent on clean, renewable energy. That's the vision of, a Stanford engineering professor who has produced a state-by-state road map of how the country could rid itself of coal oil, natural gas, and nuclear power.

By 2050, Jacobson expects the nation's transportation network - cars, ships, airplanes - to run on batteries or hydrogen produced from electricity. He sees the winds blowing across the Great Plains powering vast stretches of the country's middle while the burning sun helps electrify the Southwest. "There's no state that can't do this," Jacobson says.

Today only 13% of U. S. electricity comes from renewables（再生性能源）. Jacobson's goal would be one of the nation's most ambitious undertakings. This transformation would cost roughly $15 trillion, or $47,000 for each American, for building and installing systems that produce and store renewable energy.

What would it take? Seventy-eight million rooftop solar systems, nearly 49,000 commercial solar plants, 156,000 offshore wind turbines（风力涡轮机）, plus wave-energy systems. Land-based wind farms would need 328,000 turbines, each with blades longer than a football field,. These farms would occupy as much land as North Carolina.

For now, he says, prospects are encouraging. Thanks in part to government funding and large-scale production, costs are falling. The amount of power generated nationwide by wind and solar increased 15-fold each between 2003 and 2013. This summer Barack Obama moved to reduce carbon emissions from coal-fired power plants, and Hawaii committed to having all its electricity provided by renewables by 2045.

Still, many experts aren't convinced. “It has zero chance,”Stephen Brick, an energy fellow with the Chicago Council on Global Affairs, says of Jacobson's plan. Political, regulatory, and social barriers are huge, especially in a nation where the energy systems - and much of its political influence - is rooted in the oil, gas, and coal industries. Some critics are concerned about whether the resulting grid（输电网）would be reliable. And neighborhood battles would likely occur over wind farms and solar plants. Even outspoken scientist James Hansen, who warned the government a quarter century ago about climate change, insists that nuclear power is essential to rid the country of fossil fuels.

Yet Jacobson’s work at least offers a starting point. Scientists and policymakers may keep arguing about solutions, but as Obama points out, the nation must continue its march toward a clean-energy future even if it's not yet clear how that will look in 35 years. “If we don't do it,” he said this summer, “nobody will.”

【推荐3】Climate change in the coming decades could lead to an increase in cases of kidney stones(肾结石), according to a research by scientists in the United States.

A research team from the Children's Hospital of Philadelphia knew from previous studies that high temperatures and dehydration (脱水) increase the risk of developing kidney stones. The researchers said incidence (发生率) of the condition has increased in the last 20 years.

The scientists created a model to estimate the impact of heat on future kidney stone presentations in the southeastern US state of South Carolina, which has a higher incidence of kidney stone disease. The model predicted that the number of cases will increase between 2.2 percent and 3.9 percent by the year 2089, depending on projected daily temperatures under two climate change circumstances. In the first case, greenhouse gas emissions (排放物) are cut to an middle level as humans shift to using lower-emissions sources of energy, while in the second, emissions continue at the current rate. Meanwhile, in the first case, average temperatures increase by 2.3℃ by 2100, compared with 3.6℃ in the second. These projections were taken from studies made by the United Nations Intergovernmental Panel on Climate Change.

In comments with a news release, Gregory E Tasian, a urologist at the Children's Hospital of Philadelphia and senior author of the study, said, “While it is impossible to predict with certainty how future policies will slow or speed greenhouse gas emission and anthropogenic (人为的) climate change, and to know exactly what future daily temperatures will be, our analysis suggests that a warming planet will likely cause an increased burden of kidney stone disease on healthcare systems. As researchers, we have a duty to explore the burden of climate change on human health.”