The streets, sidewalks and roofs of cities all absorb heat during the day, making some urban areas across the United States up to 6 degrees Fahrenheit hotter than rural ones during the day—and 22 degrees F hotter at night. These “urban heat islands”   can also develop underground as the city heat spreads downward, beneath the surface. And basements, subway tunnels and other underground infrastructure also constantly bleed heat into the surrounding earth, creating hotspots. Now the underground heat is building up as the planet warms.

According to a new study of downtown Chicago, underground hotspots may threaten the very same structures that emit the heat in the first place. Such temperature changes make the ground around them expand and contract (收缩) enough to cause potential damage. “Without anyone realizing it, the city of Chicago’s downtown was deforming,” says the study’s author Alessandro F. Rotta Loria, a civil and environmental engineer at Northwestern University.

The findings, published in Communications Engineering, expose a “silent hazard (危险)” to civil infrastructure in cities with soft er ground — especially those near water — Rotta Loria says. “There might have been structural issues caused by this underground climate change that happened, and we didn’t even realize,” he adds. While not an immediate or direct danger to human lives, this previously unknown effect highlights the impacts of a lesser-known component of climate change.

Similar to climate change above the surface, these underground changes occur over long periods of time. “These effects took decades, a century, to develop,” Rotta Loria says, adding that elevated underground temperatures would likewise take a long time to dissipate (逐渐消失) on their own.

But other researchers interviewed for this story all say this wasted energy could also be recycled, presenting an opportunity to both cool the subsurface and save on energy costs. Subway tunnels and basements could be updated with technologies to recapture the heat. For example, water pipes could be installed to run through underground hotspots and pick up some of the heat energy.

At the United Nations COP27 climate conference in Egypt, UN Secretary-General Antonio Guterres claimed that the world is on a “highway to climate hell with our foot still on the accelerator (油门)”. To keep temperature from rising 1. 5 degrees Celsius above preindustrial levels by 2100, we need to pull a stop on greenhouse gas emissions. In fact, we’d basically have to bring the runaway truck to a complete and immediate stop. Now is the time for us to pull back before it is too late.

The climate pledges (承诺) made by nations at last year’s COP26 conference felt like a positive step in the right direction, but there’s very little doubt that the average temperature rise on Earth will pass the 1. 5-degree mark in the coming decades. Can we limit this overshoot? And how might we do that?

A study, released Thursday in the scientific journal Nature Climate Change, tried to answer those questions by modeling 27 different emissions reduction pathways of varying ambition. It came to an unsurprising conclusion:Countries need to act by increasing the ambition of their climate pledges. And they need to act now.

The 1. 5-degree rise has long been seen as a critical mark in the fight against climate change. Since the signing of the Paris Agreement at COP21 seven years ago, scientists have studied how this level of warming above preindustrial temperatures would affect the Earth. The models they’ve built show we are likely to see more extreme weather events, in addition to glacial melt, sea level rise that threatens many low-lying Pacific nations and significant loss of biodiversity once temperatures push past an increase of 1.5 degrees.

Though the 1. 5-degree target is practically dead, the situation isn’t hopeless. Now more than ever, there’s reason to reduce greenhouse gas emissions by setting more ambitious goals. However, ambition alone is not enough.We also need action -— investing in renewables and technologies like carbon capture and rapidly transforming our energy systems.

Among the world’s waste-recycling pioneers, Germany is the leader. The country has quite a detailed way of sorting their waste-down to the color of glass waste, the type of paper, the separate bin for metals, etc.

Here below are what you should know about Germany’s waste sorting system：

◇You are expected to gather your waste in your apartment/housing area’s local public garbage bins.

◇There are commonly several types of public garbage bins available in the German’s apartment/housing areas：

Blue bin — for paper and cardboard

Green and white bin — for glass, different bins for differently colored glass, not available for holiday decorations and lights

Yellow/orange bin — for plastic and metals

Brown bin — for goods that can be changed naturally by bacteria into substances that don’t harm the environment, like leftovers, fruit and vegetables

Gray/black bin — for everything else that can’t be recycled such as used cat litter and animal waste

◇Some items don’t belong in these public garbage bins. Items like used batteries, electronics, unused paints, and lights must be returned to the special agent/locations so they can be properly recycled. Other items such as clothes, shoes, and oversized rubbish and furniture are advised to be donated or sold.

◇There’s this thing called Pfand in Germany, a certain part of the price for a bottled drink that you get back if you send back the bottle to certified (有资历的) shops. German law requires shops over a certain size selling bottled drinks have a Pfandruckgabestelle, or place for bottles with deposits (押金). These bottles usually made of glass or plastic will be refilled. Of course, there’re strict health regulations.