We already know the fastest, least expensive way to slow climate change: Use less energy. With a little effort, and not much money, most of us could reduce our energy diets by 25 percent or more—doing the Earth a favor while also helping our wallets.

    Not long ago, my wife, PJ, and I tried a new diet—not to lose a little weight but to answer an annoying question about climate change. Scientists have reported recently that the world is bending up even faster than predicted only a few years ago, and that the consequences could be severe if we don't keep reducing emissions(排放) of carbon dioxide (CO₂ ) and other greenhouse gases that are trapping heat in our atmosphere.

    We decided to try an experiment. For one month we recorded our personal emissions of CO₂. We wanted to see how much we could cut back, so we went on a strict diet. The average US household(家庭) produces about 150 pounds of CO₂  a day by doing common-place things like turning on air-conditioning or driving cars. That's more than twice the European average and almost five times the global average, mostly because Americans drive more and have bigger houses. But how much should we try to reduce?

    For an answer, I checked with Tim Flannery, author of The Weather Makers: How Man is Changing the Climate and What it Means for Life on Earth. In his book, he had challenged readers to make deep cuts in personal emissions to keep the world from reaching extremely important tipping points, such as the melting(融化) of the ice sheets in Greenland or West Antarctica. "To stay below that point, we need to reduce CO₂  emissions by 80 percent," he said.

    Good advice, I thought. I'd opened our bedroom windows to let in the wind. We'd gotten so used to keeping our air-conditioning going around the clock. I'd almost forgotten the windows even opened. We should not let this happen again. It's time for us to change our habits if necessary.

    When the residents of Buenos Aires want to change the pesos they do not trust into the dollars they do, they go to an office that acts as a front for thriving illegal exchange market.

    As the couriers carry their bundles of pesos around Buenos Aires, they pass grand buildings like the Teatro Colon, an opera house that opened in 1908, and the Retiro railway station, completed in 1915. In the 43 years leading up to 1914, GDP had grown at an annual rate of 6%, the fastest recorded in the world. In 1914 half of Buenos Aires's population was foreign-born. Its income per head was 92% of the average of 16 rich economies.

    It never got better than this. Its income per head is now 43% of those same 16 rich economies; it trails Chile and Uruguay in its own backyard.

    The country's dramatic decline has long puzzled economists. “If a guy has been hit___shots it's hard to work out which one of them killed him.” says Rafael di Tella. But three deep-lying explanations help to throw light on the country's decline. Firstly, Argentina may have been rich 100 years ago but it was not modern. The second theory stresses the role of trade policy. Thirdly, when it needed to change, Argentina lacked the institutions to create successful policies.

    Argentina was rich in 1914 because of commodities; its industrial base was only weakly developed. The landowners who made Argentina rich were not so bothered about educating it: cheap labor was what counted.

    Without a good education system, Argentina struggled to create competitive industries. It had benefited from technology in its Belle Epoque period, but Argentina mainly consumed technology from abroad rather than inventing its own.

    Argentina had become rich by making a triple bet on agriculture, open market and Britain, its biggest trading partner. If that bet turned sour, it would require a severe adjustment. The First World War delivered the initial blow to trade. Next came the Depression, which crushed the open trading system on which Argentina depended. Dependence on Britain, another country in decline, backfired(失败) as Argentina's favored export market signed preferential deals with Commonwealth countries.

    After the Second World War, when the rich world began its slow return to free trade with the negotiation of the General Agreement on Tariffs and Trade in 1947, Argentina had become a more closed economy. An institution to control foreign trade was created in 1946; the share of trade as a percentage of GDP continued to fall. High food prices meant big profits for farmers but empty stomachs for ordinary Argentines. Open borders increased farmers' taking but sharpened competition from abroad for domestic industry. Heavy export taxes on crops allow the state to top up its decreasing foreign-exchange reserves; limits on wheat exports create surpluses(过剩) that drive down local prices. But they also dissuade farmers from planting more land, enabling other countries to steal market shares.

    US people are overweight, eat lots of fast food and fill their homes with pets. At least that's what 21 European teenagers think.

    The students, 18 from Germany and 3 from France, are exchange students. They are studying in the US for a year. After a few days in the US, they said what they thought about the country.

    Most talked about the amount of fast food US people eat. It's not that the students don't eat fast food. They just don't eat as much.

    Laetitia Villeneuve from France said she eats fast food, usually McDonald's, only once or twice a year.

    "I like it," said Nora Koeberle from Germany. "But I couldn't eat it every day. I'd get fat. "

    Students are surprised at how big US people seem.

    "There are fat people in Germany," said Antonia Greimel from Germany. "But not as many as there are here."

    They also spoke about the animals. Silvana Wolfram from Germany said she had heard about how people had lots of pets in the US.

    Other ways of US high schools interested the students.

    For example, Koeberle said she wouldn't be able to play an instrument or sports as part of her classes in Germany. She can in the US.

    But the best thing about US high schools is something the European kids can't get back home. "I do wish we had parties," Koeberle said.

    Next month, I'm traveling to a remote area of Central Africa and my aim is to know enough Lingala — one of the local languages — to have a conversation. I wasn't sure how I was going to manage this — until I discovered a way to learn all the vocabulary I'm going to need. Thanks to Memrise, the application I'm using. It feels just like a game.

    "People often stop learning things because they feel they're not making progress or because it all feels like too much hard work," says Ed Cooke, one of the people who created Memrise. "We're trying to create a form of learning experience that is fun and is something you'd want to do instead of watching TV."

    Memrise gives you a few new words to learn and these are "seeds" which you plant in your "greenhouse". When you learn the words, you "water your plants". When the application believes that you've really memorized a word, it moves the word to your "garden". And if you forget to log on, the application sends you emails, reminding you to "water your plants".

    The application uses two principles about learning. The first is that people memorize things better when they link them to a picture in their mind. Memrise translates words into your own language, but it also encourages you to use "mems". For example, I memorized motele, the Lingala word for "engine", using a mem I created — I imagined an old engine in a motel (汽车旅馆) room.

    The second principle is that we need to stop after studying words and then repeat them again later, leaving time between study sessions. Memrise helps you with this, because it's the kind of application you only use for five or ten minutes a day.

    I've learnt hundreds of Lingala words with Memrise. I know this won't make me a fluent speaker, but I hope I'll be able to do more than just smile when I meet people in Congo. Now, I need to go and water my Vocabulary!

    In the near future, IoT (Internet of Things) will drive huge innovation (革新) in the way our food is grown. Plants will have a "voice", not a human voice, but a voice based on data that can tell people, computers, and machines when, for example, they are thirsty, or need more sun, medicine, etc.

    Take vertical (垂直的) farms, for example. Farming is moving indoors where the growth of plants can be monitored and controlled. The facilities are built vertically, so growing areas can be put in piles. This greatly reduces the amount of land needed for farming.

    From an IoT point of view, vertical farms are connected in two ways. First, small sensors (传感器) in the soil or connected to plants tell a control system exactly how much light, water, and nutrients are needed to grow the healthiest crops. Sensors will also tell vertical farmers when crops are nearing their peak for harvesting at just the right time to make sure it's still fresh when it reaches its final destination.

    Second, vertical farms will be connected to other networks and information systems, including databases that track local demand. For example, local restaurants may input when they need fresh food supplies. And vertical farmers could get that information so they know which crops to grow in what quantities. This type of IoT system would have been unimaginable a generation ago.

    Today, vertical farms are being experimented. Yet, the numbers point to a bright future for the industry, especially as the world's population continues to grow. For example, Green Sense Farms in Chicago is able to harvest crops 26 times a year using 85 percent less energy, one-tenth the water, and no pesticides. A side benefit of lower energy use is lower CO₂ output of two tons per month, with the added benefit of creating 46 pounds of oxygen every day.

    China became the first country to clone a monkey using non-reproductive cells, reducing the need to keep lab monkeys and paving the way for more accurate, effective, and affordable animal tests for new drugs.

    By December of 2017, Chinese scientists had created two clone macaques named "Zhong Zhong" and "Hua Hua" by nuclear transferring of somatic cells -- any cell in the organism other than reproductive cells. This was the similar technology used to create the famous clone sheep Dolly in 1996.

    Tetra, a rhesus monkey born in 1999, is the world's first ever-cloned monkey, but it was done using a simpler method called embryo splitting, but it could only generate four cloned offspring at a time and cannot be genetically modified to suit experimental needs, said Pu Muming, an academician at the Chinese Academy of Sciences and the director of Institute of Neuroscience, CAS. "Cloning a monkey using somatic cells has been a world-class challenge because it is a primate（灵长类）that shares its genetic makeup, therefore all of its complexity, with humans." Pu Muming said.

    "For drug and other lab tests, scientists have to purchase monkeys from all over the world, which is costly, bad for the environment and produces inaccurate results because each monkey might have different genes," Pu said. "By cloning monkeys using somatic cells, we can mass produce large numbers of genetically same offspring in a short time, and even change their genes to suit our needs," he added. "This can save time, cut down experiment costs, and produce more accurate results, leading to more effective medicine."

    Sun Qiang, director of the non-human primate research facility at the institute, said most of the drug trials are currently done on lab mice. However, drugs that work on mice might not work or even have severe side effects on humans because the two species are so different. "Monkeys and Humans are both primates, so they are much closely related and testing on Monkeys is supposed to be as effective as testing on humans," he said. This is especially useful in testing drugs for neural diseases such as Parkinson's disease, metabolic and immune system disease, and tumor, he added. "This achievement will help China lead the world research in an international science project related to neural（神经的）mapping of primate brains,"he said. However, bio labs from the United States, Japan, and European countries are also very able, and they will quickly catch up to China after the monkey cloning technology is made public, Sun added." This means we have to innovate continuously and work extra harder this year to stay ahead," he said.