2 . Whenever I order food for delivery, I play a little game to guess how many sets of tableware(餐具)the restaurant will provide with my meal. Sometimes restaurants will throw in two, three or four sets for just one order. But I rarely need any tableware at all, and the waste goes into the trash or collects dust in a kitchen drawer.

Researchers working with Chinese technology group Alibaba tried a simple approach to this problem. Instead of just wastefully doling out tableware, the company required food-delivery customers in some cities in China to pick how many sets of tableware they wanted to receive.The default (默认设置)was set at zero. The result, published today in the journal Science, was a 638% increase in the share of no-tableware orders. If applied across China, researchers found, the approach would save nearly 22 billion sets of plastic tableware. The study doesn’t cover carbon emissions, but it’s safe to say that the impact would be significant. It struck me as a useful reminder of the many low-hanging fruits across the economy that can cut waste, and emissions.

Nudging its customers cost Alibaba nothing more than a few hours of software engineering time and the impact it brought was immense. The concept of nudging comes from the field of behavioral economics known as nudge theory. It suggests that a slight action can encourage good human behavior without the need for policies that limit choice or economic punishment that raises the cost of bad behavior. To nudge customers to eat better, for example, a restaurant might organize its menu by listing healthy options first and bury unhealthy ones at the bottom. More recently, some big companies like Google have also begun to use nudges to advance climate objectives.

Behavioral economics broadly, and nudges more specifically, aren’t without controversy. Some might think it assigns consumers responsibility for addressing environmental challenges. But there is another way to look at it. In the absence of necessary policy—and policy is needed一companies can help encourage a widespread shift of consumer behavior.

And all of that behavioral change can add up. The International Energy Agency found in 2021 that small behavioral changes in energy consumption such as walking instead of driving and adjusting the thermostat could in total shave off 4% of global emissions. The more that companies can do to facilitate such changes, the better.

3 . Slowly, a great white shark swims toward the boat and onto a specialized lift. Once the shark is lifted onto the boat, the research team from OCEARCH, a nonprofit that specializes in shark tracking, performs about a dozen procedures.

The work is part of OCEARCH’s efforts to study great whites in the western North Atlantic, a less well-researched population than others around the world. “Here we are at the location of Jaws, and yet we didn’t really know the animals as well as we should,” says Bob Hueter, the chief scientist.

Two young great whites tagged (打标签) in this way, Simon and Jekyll, recently became famous thanks to a social media post that pointed out the pair had been traveling together for 4,000 miles up the North American Atlantic coast. People began to wonder if the sharks might be friends, but the situation is not so simple.

The two males were first tagged off the coast of Georgia in December 2022．The electronic tags transmit (传送) data via satellite when one of the sharks surfaces, allowing researchers to follow the animals’ movements online in real time. When Simon and Jekyll reached Long Island, researchers noticed their tracks were remarkably similar. Then they arrived in Novia Scotia within practically the same day!

Although this was a one-time event, such a similar route for the two sharks over a longtime and distance is significant. Great whites are traditionally viewed as solitary (独行者), but researchers believe they may display some social behaviors like other shark species. One study found that white sharks may remain close while hunting to benefit from food. “Surprisingly, we see more and more that white sharks might fit into that social category,” says Yannis Papastamatiou, a biologist at Florida International University.

However, Salvador Jorgensen, a marine ecologist at California State University, thinks there may be other reasons why the pair followed the same route.

4 . As a research scholar at the Indian Institute for Science Education and Research, I once monitored birds that inhabited grasslands in Daying Ering Memorial Wildlife Sanctuary, a protected area in Northeast India. This habitat forms a part of one of the most bio-diverse places on Earth. Yet despite their ecological importance and uniqueness, most grasslands are classified by the Indian government as “wastelands”.

Ecosystems throughout the world are suffering from the effects of unchecked habitat loss and climate change. While all types of ecosystems—forests, grasslands, oceans, wetlands and deserts—feel these effects, there is evidence of bias (偏好) towards the conservation of forest biodiversity. This bi as hurts the preservation of other ecosystems, including the grasslands that make up 24 percent of the Indian landmass. These grasslands are home to important biodiversity and support the livelihoods of millions of people, yet are defined in India by their value in being turned into forests for fighting climate change.

Apart from being costly, the move overlooks the ecological and social value of grasslands by turning them into mono-culture forests, which do not provide the same ecological benefits. Yet, grasslands could be equally good at storing carbon.

India and other countries with substantial grasslands need to recognize, support and prioritize evidence-based scientific attempts that focus on grasslands by establishing grassland-specific restoration efforts, as well as by mapping their extent and the ecosystem services they provide for humans. The time is ripe for abandoning outdated labelings like “wastelands”.

Already, communities like the Todas and the Idu Mishmi people are protecting grasslands in India through collective action and local stewardship (管理), which are helping them connect with the grasslands. With the aim of preserving the richness of nature, the government must restore greater rights to local communities to manage grasslands. Grasslands are an important feature of an ecologically sound India, one that must be preserved for that value above all others.

5 . In a joint effort to tackle the climate crisis, humans are turning to offshore wind farms (OWFs) as a source of renewable energy. OWFs are, quite literally, one of the biggest forms of renewable energy. The world’s largest OWF covers an area of 462 square kilometers, with each turbine (涡轮) standing 200 meters above the sea. It has the capacity to power over 1.4 million homes. But what impact do the towering turbines have on life in the waters below and the skies above?

It’s thought that OWFs could affect marine (海洋的) life in a number of ways, from noise disturbing the behaviors of fish and whales to changes in the diversity of species in the area. Seabirds that live in the North and Baltic Seas — where a vast majority of OWFs are placed — are also thought to be endangered by turbines. A report from Bird Life International found that twelve North and Baltic seabird species were at high risk of crashing with farms and seven at high risk of being displaced by their construction.

Not all impacts are negative though — some research has suggested that OWFs have the potential for environmental benefits too. A study following the movement of gray seals in the North Sea found that they were frequent visitors to two OWFs, searching between turbines for food. The researchers suggested that farms be acting like artificial reefs, representing a new and concentrated source of food. In areas where marine life has become less dense, it could allow life to flourish (繁荣) once again.

Even so, researchers explained that it’s difficult to predict the full extent of the potential environmental outcomes from these unexpected artificial reefs: “Only a small proportion of our study seals used wind farms or pipelines,” study author Deborah Russell told The Guardian at the time.

To avoid replacing one problem by creating a new one, it seems that researchers and developers will have to continue working hand in hand to ensure OWFs and marine life can successfully live side by side.

6 . The combined quantity of water on Earth has varied over the course of our planet’s geological history, and it still does.

Today, Earth includes some 1,386 million cubic kilometres of water, a volume that includes water in oceans, lakes and rivers, plus ground water, vapour in the atmosphere, and the frozen water of glaciers and ice caps. On the young Earth — some four billion years ago — vast quantities of water were added to the planet by ice-containing comets (a mass of ice and dust that moves around the sun and looks like a bright star with a tail) that struck us, eventually making our world a “blue planet”. But such events became increasingly rare in Earth’s more recent history, and today we are in an age during which Earth is losing water.

The water loss is due to the fact that particles (微粒) sometimes escape Earth’s gravity to travel into space. This is particularly true of the light hydrogen atoms that form part of water molecules (分子) together with oxygen. Every time the atmosphere loses hydrogen, we lose one of the building blocks of water. Scientists estimate that Earth loses about 3kg of hydrogen per second. At this pace, Earth would run out of water in three billion years — but that assumes that we don’t get any new water supplies.

New water need not come from space — it might come from the inside of the Earth. At depths below 50km, minerals contain water that is not reckoned within the water cycle. Some of it dates back to Earth’s formation; the rest is part of slow geological exchange between the planet’s layers. When Earth’s plates sink and melt, deep minerals can release these bound water molecules so that they can subsequently rise to the surface via volcanic eruptions, adding to the planet’s overall water resources.

7 . As founder of the Global Water Policy Project and lead expert for National Geographic’s Freshwater Initiative, Sandra’s goal is to promote the conservation and sustainable use of the Earth’s freshwater resources.

Sandra says she grew up in New York as a Long Island beach kid. She was always a ware of the “comfort, peace, and balance” offered by the natural world, especially the environments of wetlands and rivers. Before starting work on a project, Sandra considers an area’s “geography of water”: the amount of water in the area’s basin, the population, and the agricultural use of water. The geography of water helps Sandra determine an area’s water stress. Water stress is the situation where a community is using more water than nature made available.

Sandra first became aware of the concept of water stress after reading Swedish hydrologist Malin Falkenmark’s book Water for a Starving World. This groundbreaking work linked water use, food and population. As Sandra began to understand water stress, she realized it affects everything, from a community’s development to its political security. “So many great civilizations developed alongside rivers and lakes,” she says, pointing to the ancient civilizations of Ur (between the Tigris and Euphrates rivers), Egypt (which developed on the Nile), and the Indus River Valley.

Today, Sandra points out, more than 200 rivers are shared between two or more nations. Dams and other river management techniques implemented (实施) by nations upstream have a huge impact on nations downstream. The Tigris and Euphrates rivers have their sources in Turkey, for example, but their basins are in Iraq, Kuwait, Saudi Arabia, and Syria. River management from Turkey would impact the freshwater available to these countries for drinking, hygiene (卫生), industry, and transportation.

Water management has become part of many nations’ foreign policy. Sandra points to the Mekong River Commission. The headwaters of the Mekong River are in China, although the basin is nearly 800,000 square kilometers and includes the nations of Myanmar, Cambodia, Laos, Thailand, and Vietnam. Many governments are members of the Mekong River Commission, which promotes sustainable development of the water supply.

8 . Janet Kelly and her husband, DaQuan Davis, were out shopping one afternoon when DaQuan’s brother, Demetrius, called in a panic. Some children playing with a lighter in the downstairs apartment ______ a fire, and the whole house was on fire. ______, Janet’s two youngest children were still inside. But when they got back, they learned that their children were ______.

That’s when Janet ______ that their dog, named Blue, had played a big role in ______ their youngest daughter. Demetrius ______ the older one of the two children out first, but when he ______ for the younger one, the smoke was ______ and things were falling all around him, Blue had ______ Demetrius outside, and then he ran back into the house for the younger child. “He was circling around my daughter and ______. Firefighters arrived in minutes. They followed Blue’s sounds to ______ the child,” Janet said.

The family were especially ______ to Blue. “He’s the sweetest dog,” Janet said. “Blue will bark at strangers, but once he knows you’re OK, he’ll drop onto his back for belly rubs.” Blue has clearly been affected by the ______ and he now barks whenever he sees candles or someone lighting a cigarette. ______, Blue has become a bit of a ______ for the family. Blue, you’re the ultimate good boy