1 . As the planet gets hotter, the need for cool living environments is becoming more urgent. But air conditioning is a major contributor to global warming since units release powerful greenhouse gases and use lots of energy.

Now, researchers from McGill University, UCLA and Princeton have found in a new study an inexpensive, sustainable alternative to mechanical cooling with refrigerants (制冷剂) in hot and dry climates, and a way to relieve dangerous heat waves during electricity blackouts.

The researchers set out to answer how to achieve a new benchmark (基准) in passive cooling inside naturally conditioned buildings in hot climates such as Southern California. As an attempt, they examined the use of roof materials that radiate (辐射) heat into the cold universe, even under direct sunlight, and how to combine them with temperature-driven ventilation (通风). These cool radiator materials and coatings are often used to stop roofs overheating. Researchers have also used them to improve heat rejection from chillers. But there is untapped potential for integrating them into architectural design more fully, so they can not only reject indoor heat to outer space in a passive way, but also drive regular and healthy air changes.

“We found we could maintain air temperatures several degrees below the current surrounding temperature, and several degrees more below a reference ‘gold standard’ for passive cooling,” said Remy Fortin, lead author and PhD candidate at the Peter Guo-hua Fu School of Architecture. “We did this without sacrificing healthy ventilation air changes.” This was a considerable challenge, considering air exchanges are a source of heating when the aim is to keep a room cooler than the outside.

The researchers hope the findings will be used to positively impact communities suffering from dangerous climate heating and heatwaves. “We hope that materials scientists, architects, and engineers will be interested in these results, and that our work will inspire more complete thinking for how to integrate breakthroughs in radiative cooling materials with simple but effective architectural solutions,” said Remy Fortin.

2 . The heavy use of fossil fuels over the last 150 years has released massive amounts of greenhouse gases, which has caused the Earth to warm up. Scientists say large amounts of CO₂ must be removed from the atmosphere and stored. Plants and trees do this naturally. But there’s so much CO₂ in the atmosphere that just planting trees and protecting forests won’t solve the problem. And, when these plants and trees die, the carbon they’ve stored gets released again. That means humans need to come up with ways of removing carbon from the air and storing it. This is called Direct Air Capture(DAC).

A company called Heirloom has just opened the first DAC plant in the United States. Heirloom’s process uses limestone to capture CO₂. The company heats up the limestone to separate out the CO₂, which is then locked away in concrete. Heirloom uses renewable electricity to produce the heat, so the process doesn’t produce more CO₂. The process is extremely expensive though. The new plant can remove 1,000 tons of CO₂ a year. That’s a tiny amount compared to how much carbon needs to be removed from the atmosphere.

Graphyte is another US company working on DAC. The company collects unwanted plants. It dries this “biomass” completely so that it can’t break down. Graphyte then strikes the dried plants into small bricks which are trapped in a special wrapper and buried deep underground. Graphyte says its process doesn’t use much energy and can work anywhere. The company claims the cost is merely less than $100 to capture a ton of CO₂.

Not everyone is excited about carbon removal. Some people worry that it will take too long to make a difference. Others worry that focusing on removing carbon could take attention away from more important climate actions, like switching from fossil fuels to renewable energy. But experts say the decision isn’t to do one or the other. The world needs to end fossil fuel use and pull carbon out of the air.

9 . Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease. But there is another factor that can cause your heart problems more immediately: the air you breathe.

Previous studies have linked high exposure (暴露) to environmental pollution to an increased risk of heart problems, but two analyses now show that poor air quality can lead to heart attack or stroke (中风) within as little as a few hours after exposure. In one review of :he research, scientists found that people exposed to high levels of pollutants (污染物) were up to 5% more likely to suffer a heart attack within days of exposure than those with lower exposure. A separate study of stroke patients showed that even air that the U. S. Environmental Protection Agency(EPA) considers to be of “moderate” (良好) quality and relatively safe for our health can raise the risk of stroke as much as 34% within 12 to 14 hours of exposure.

The authors of both studies stress that these risks are relatively (相对地) small for healthy people and certainly modest compared with other risk factors such as smoking and high blood pressure However, it is important to be aware of these dangers because everyone is exposed to air pollution regardless of lifestyle choices. So stricter regulations by the EPA of pollutants may not only improve environmental air quality but could also become necessary to protect public health.

10 . A lot of manufactured glass today made from sand and sodium carbonate(碳酸钠) can be reused or melted down and recycled into new items, but it doesn’t break down in the environment and will sit in landfills for thousands of years. A team of Chinese scientists aimed to deal with this environmental concern by developing an eco-conscious alternative.

In a study published recently in the journal Science Advances, a team at the Chinese Academy of Sciences’ Institute of Process Engineering describe how they engineered biodegradable glass made from amino acids(氨基酸). That glass would have a smaller impact on the environment and can break down in a few weeks or in several months.

In a test, glass beads(玻璃珠) made out of amino acids were placed under the skin of mice, and the breakdown of the bead and the skin healing process were observed for 30days. A diagram from the study shows how the mice’s bodies broke down the beads. In that month, the glass implant degraded beneath the skin, the wound site healed, and fur grew back. “Throughout the experimental period, no mice exhibited any pain-related behavior that may have been caused by the glass implantation, and none of them experienced obvious weight loss,” the researchers wrote in their paper.

Although amino acids do degrade over time in the environment, this biodegradable glass is not as durable as traditional glass, because amino acids can break down quickly in heat. In order to overcome this hurdle, the researchers chemically modified the amino acids using the heating-cooling procedure applied in glass manufacturing. This is when materials for the glass are heated to become soft and then rapidly cooled so as to make the glass tougher.

“It’s important to point out that this biodegradable glass is currently in the lab stage, and far from large-scale commercialization,” emphasized Yan Xuehai, a professor involved in the study, in a press release.