Frightened passengers trapped in flooded subway cars in Zhengzhou, China. Water pouring down stairways into the London Underground. A woman walking through dirty, deep water to reach a New York City subway station.

Subway systems around the world are fighting with terrible weather brought on by climate (气候) change. Some networks, such as London’s or New York’s, were designed and built starting more than a century ago. At the same time, the crisis (危机) in China shows that even some of the world’s newest systems (Zhengzhou’s system isn’t even 10 years old) can also be overwhelmed (压倒).

“It’s terrible,” said Sarah Kaufman, director of the Rudin Center for Transportation at New York University. “The challenge is, how can we get ready for the next storm, which was supposed to be 100 years away,” she said, “but could happen tomorrow?”

Just days before the China subway crisis, floods in Germany killed more than 160 people. As Robert E. Paaswell, a professor at City College of New York, put it: “Subways are going to flood. They’re going to flood because they are below ground.”

With more terrible flooding down the line, protecting subways all of the time will be impossible. Instead, money is needed in buses and bike lanes (车道) that can serve in other ways of public transportation when subways are flooded.

Some researchers question why public transportation needs to be underground in the first place and say that public transportation should reclaim (重新占领) the street.“We have this habit from the last century to give so much of the space above ground to cars,” he said. “But one bus lane carries more people than three lanes of cars.” said Bernardo Baranda Sepúlveda, a Mexico City-based researcher at the Institute for Transport Development

We go to many places every day. How do you usually go for a trip? Walk or ride a bike?In a city, there are many ways for you to choose(选择)when you go out for a trip. If(如果)you can take a taxi, there are many car-hailing(网约车)apps now.You can order(预定)online.

You can also choose to take the subway. It is much faster than(比……更快)buses.You don’t need to pay a lot for it. When you are not busy, you can take a bus.You can see the nice city on the bus. If the place isn’t far, walking is good for you.

Today, many people have cars. They go to work by car. They go for trips by car, too. But do you think it’s a good thing to have lots of cars on the street?