Recently, we have already shown that climate change has led to a dramatic increase in storm surge risk in New York City, making devastating events like Hurricane Sandy more likely.

    What can we say about the role of climate change in the unprecedented disaster that is unfolding in Houston with Hurricane Harvey? There are certain climate change-related factors that we can, with great confidence, say worsened the flooding.

    Sea Level rise attributable to climate change-some of which is due to coastal subsidence(下沉) caused by human disturbance such as oil drilling-is more than half a foot(15cm) over the past few decades. That means the storm surge was half a foot higher than it would have been just decades ago, meaning far more flooding and destruction.

    In addition to that, sea surface temperatures in the region have risen about 0.5C(close to 1F) over the past few decades from roughly 30C(86F) to 30.5C(87F), which contributed to the very warm sea surface temperatures(30.5-31C, or 87-88F). There is a simple thermodynamic(热力学的) relationship known as the Clausius-Clapeyron equation that tells us there is a roughly 3% increase in average atmospheric moisture content for each 0.5C of warming. Sea surface temperatures in the area where Harvey intensified were 0.5-1C warmer than current-day average temperatures, which translates to 1-1.5C warmer than “average” temperatures a few decades ago. That means 3-5% more moisture(水分) in the atmosphere. That large amount of moisture creates the potential for much greater rainfalls and greater flooding. The combination of coastal flooding and heavy rainfall is responsible for the devastating flooding that Houston is experiencing.

    Not only are the surface waters of the Gulf of Mexico unusually warm right now, but there is a deep layer of warm water that Harvey was able to feed upon when it intensified at near record pace as it neared the coast. Human-caused warming is penetrating down into the ocean. It's creating deeper layers of warm water in the Gulf and elsewhere. Harvey was almost certainly more intense than it would have been in the absence of human-caused warming, which means stronger winds, more wind damage and a larger storm surge.

    Finally, the more tenuous but potentially relevant climate factors: part of what has made Harvey such a devastating(毁灭性的) storm is the way it has stalled near the coast. It continues to strike Houston and surrounding regions with a seemingly endless flood, which will likely top out at nearly 4ft(1.22m) of rainfall over a days-long period before it is done. The stalling is due to very weak prevailing winds, which are failing to steer the storm off to sea, allowing it to spin around and wobble back and forth. This pattern, in turn, is associated with a greatly expanded subtropical high pressure system over much of the US at the moment, with the jet stream pushed well to the north. This pattern of subtropical expansion is predicted in model simulations of human-caused climate change. More tenuous(微弱的), but possibly relevant still, is the fact that very persistent, nearly “stationary” summer weather patterns of this sort, where weather anomalies(both high-pressure dry hot regions and low-pressure stormy/rainy regions) stay locked in place for many days at a time, appears to be favoured by human-caused climate change.

    In conclusion, while we cannot say climate change “caused” Hurricane Harvey, what we can say is that it exacerbated several characteristics of the storm in a way that greatly increased the risk of damage and loss of life. Climate change worsened the impact of Hurricane Harvey.

My dad was in the Air Force. When I was a kid, we moved every few years. That meant a lot of good-byes. It also meant getting used to a whole new community and a whole new school each time we moved. I can still feel what it was like to have to walk into the new school—that sinking feeling in my belly, that heaviness in my throat. It would always take time for me to learn how everything worked, what was cool and what not. It was always a struggle to find where I could fit in.

    Already shy, I didn't have much self-confidence in my friend-making abilities. I was the girl walking in the halls with her head down, panicking. When I spoke, you could hardly hear my soft voice. I was nervous and doubted myself a lot.

    It was very hard not having a history with everyone else. I was an outsider. But what I did have was soccer. Wherever I went, I knew that I could fit it with the soccer ball. The soccer team meant a familiar place and immediate friends for me. I could express myself and feel good about myself on the field. Playing hard helped to get rid of all my nervousness.

    Throughout our lives, our self-respect goes down when we feel like a failure, and it goes up when we feel successful. Doing something well, being praised, and feeling loved goes a long way. We all need to explore opportunities where we can be good at something and feel good about ourselves. Physical activity and sport participation is a terrific way to build up our sense of self-confidence and self-worth.

    June 8

    Culinary (烹饪的）Historians of Washington: Food historian Joel Denker discusses how certain foods acquired culinary significance and ceremonial and economic importance. 2-4 pm .Free. Bethesda-Chevy Chase Regional Services Center, Meeting Room A，4805 Edgemoor Lane，Bcthcsda. 202-487-6740.

    June 11

Beers of Umbria: Beer director Scott Weiss leads a tasting of Italian beers. 7:30 pm. $35, Via Umbria, 1525 Wisconsin Avenue. NW. 202-333-3904.

    June 13

    Wine Dinner: A special menu paired with sparkling (气泡的）wine. 6:30 pm. $75, not including tax and gratuity (小费).Wildfire. Tysons Galleria. Third Floor. 1714 International Dr., McLean. 703-442-9110.

    June 14

    Cooking Class: Chef Gerard Pangaud demonstrates (展示) how to make several seasonal French dishes.11 am-2 pm. $85. Hill Center at the Old Naval Hospital, 921 Pennsylvania Avenue. SE. 202-549-4172.

    Hot Drinks from Around the World: Participants learn about and sample drinks made from purple com. yak (牦牛) butter, orchid root and more. 10 am. $27. Green Spring Gardens, 4603 Green Spring Road, Alexandria.

    June 18 pm-地 Columbu

    Gourmet Symphony: A special American cuisine-inspired menu accompanied performance by the Inscape Chamber Orchestra. VIP option available.7-9 pm. $49 Columbia Firehouse, 109 S. Saint Asaph St, Alexandria.

    June 28

    Sips: Cocktail reception featuring local artisans (技工）and mixologists (调酒师) benefit D.C. Central Kitchen and Martha's Table. VIP tickets also availabi 7:30 pm. $125 by

    June. 11；$150 thereafter. Newseum, 555 Pennsylvania Ave.NW.

    June 29

    Suppers：Fundraising dinners taking place in more than 35 area homes, featuring chefs Alon Shaya,Carla Hall,Tim Ma,

    Amy Brandwein and more. Proceeds benefit D.C. Central Kitchen and Martha's Table.6 pm. $600.

    Let us all raise a glass to AlphaGo and the advance of artificial intelligence. AlphaGo, DeepMind's Go-playing AI, just defeated the best Go-playing human, Lee Sedol. But as we drink to its success, we should also begin trying to understand what it means for the future.

    The number of possible moves in a game of Go is so huge that in order to win against a player like Lee. AlphaGo was designed to adopt a human—like style of gameplay by using a relatively recent development--deep learning. Deep learning uses large data sets," machine learning" algorithms （计算程序） and deep neural networks to teach the AI how to perform a particular set of tasks. Rather than programming complex Go rules and strategies into AlphaGo DeepMind designers taught AlphaGo to play the game by feeding it data based on typical Go moves. Then, AlphaGo played against itself, tirelessly learning from its own mistakes and improving its gameplay over time. The results speak for themselves.

    Deep learning represents a shift in the relationship humans have with their technological creations. It results in AI that displays surprising and unpredictable behaviour. Commenting after his first loss, Lee described being shocked by an unconventional move he claimed no human would ever have made. Demis Hassabis, one of DeepMind's founders, echoed this comment:"We're very pleased that AlphaGo played some quite surprising and beautiful moves."

    Unpredictability and surprises are—or can be—a good thing. They can indicate that a system is working well, perhaps better than the humans that came before it. Such is the case with AlphaGo. However, unpredictability also indicates a loss of human control. That Hassabis is surprised at his creation's behaviour suggests a lack of control in the design. And though some loss of control might be fine in the context of a game such as Go, it raises urgent questions elsewhere.

    How much and what kind of control should we give up to AI machines? How should we design appropriate human control into AI that requires us to give up some of that very control? Is there some AI that we should just not develop if it means any loss of human control? How much of a say should corporations, governments, experts or citizens have in these matters? These important questions, and many others like them, have emerged in response, but remain unanswered. They require human, not human - like, solutions.

    So as we drink to the milestone in AI, let's also drink to the understanding that the time to answer deeply human questions about deep learning and AI is now.

    Should Parents Teach Children How to Tweet?

    Social media is a seemingly endless source of concern for parents, with worries that it weakens their children's confidence and attention spans. But others counter that it could also be broadening their horizons.

    The latest round of worry was sparked by a study of the impact of social media use on 8-12- year-olds published by Anne Longfield, Children's Commissioner for England. The report focused on 32 children, who said they used social media to stay connected with friends and family and to have fun, by watching videos for example. But they also described pressures from constant contact, online comments that weaken their self-esteem, and the need to shape offline activities to make them shareable. "You see your friends going ice skating, partying or talking about how much revision they have done, and it can make you feel inadequate," says Bea, a junior school student from Bristol, UK. "It's just so hard to get away from."

    Children have to take risks on their journeys to adulthood, and desires to fit in and be popular existed before Mark Zuckerberg came along with Facebook. However, in previous generations these pressures came largely from people they knew, and they mostly stayed outside the home. Now the pressures could come from any one of the nearly 3 billion people online, and follow them from school to home, and can even continue through the night.

    The pressures do get on parents' nerves, among which the utmost concern is how their children can be protected from harms, given that social media is now integral to the way many young people interact. A good starting point is a basic understanding of childhood development milestones.

    Broadly, children have a high dependency on carers for security and guidance up to the age of 5, increasing independence and self-care from 6 to 11, and increasing autonomy and growing reliance on peers from 12-18 years old. Against this background, the suitability of social media for children of different ages should be considered respectively.

    According to Longfield's study, children should be taught about online safety from an early age, better before secondary school. There is growing evidence that efforts need to be extended to provide earlier guidance on less extreme but more common risks, including oversharing, low selfesteem, addiction and insomnia. The evidence suggests she is right. However, approaches that focus merely on the potential negatives are unlikely to work.

    "My school has tried to do a lot, but it often involves trying to drill into us how bad social media can be," says Bea. "People of my age really like social media, so I think a better approach would be if they said ‘Although it is good, here are some negatives'."

    Food sometimes gets poisoned with harmful things. A person who eats such food can get an illness called food poisoning. Food poisoning is usually not serious, but some types are deadly. The symptoms of food poisoning usually begin within hours of eating the poisoned food. Fever is one of the most common symptoms.

    Certain microorganisms(微生物)cause most types of food poisoning. Bacteria and other microorganisms can poison eggs, meat, vegetables, and many other foods. After entering the body, these tiny living things release(释放)poisons that make people sick.

    Some chemicals can also cause food poisoning. They are often added to food while it is being grown, processed, or prepared. For example, many farmers spray chemicals on crops to kill weeds and insects. Some people may have a bad reaction to those chemicals when they eat the crops.

    Some plants and animals contain natural poisons that are harmful to people. These include certain kinds of seafood, grains, nuts, seeds, beans, and mushrooms.

    When people handle food properly, the risk of food poisoning is very small. Microorganisms multiply rapidly in dirty places and in warm temperatures. This means that people should never touch food with dirty hands or put food on unwashed surfaces. Food should be kept in a refrigerator to stop microorganisms from growing. Meat needs to be cooked thoroughly to kill any dangerous microorganisms. People should also wash food covered with chemicals before eating it. Finally, people should not eat wild mushrooms or other foods that grow in the wild. Some of these foods may contain natural materials that are poisonous to humans. In addition, some types of fish can be poisonous.

    Most people recover from food poisoning after a few days of resting and drinking extra water. If people eat natural poisons, they must go to the hospital right away to have their stomachs emptied.