4 . As the effects of climate change set in, coastal cites such as the Italian city of Venice and the American city of New Orlean are slowly sinking. So is Bangkok. Officials in the city and scientists say they do not know how long people will be able to continue living in the Thai capital.

Thailand’s military rulers are considering action. The National Reform Council wants the government to form a committee to deal with the warnings that Bangkok could be permanently underwater many years from now.

The Saen canal was built in Bangkok in the late 1830s. In a neighborhood near the waterway, walkways are breaking up. Walls on homes, small businesses and an Islamic center appear to be bending. The area is sinking about two centimeters a year, which is two times the average rate for the rest of Bangkok.

“I don’t know what to do.” says Vijitri Puangsiri who has lived in the neighborhood for 44 years. Her home needs to be repaired every year because of the sinking ground. The walkway in front of her century-old house where she operates a small restaurant must also be repeatedly repaired.

“If you travel on the canal boats, you can see how this is all hollow,” Somsak Kongeeng says, “The buildings to see him are sinking because they were not built on solid foundations,” He joked that if we come back to see him again in 20 years, the water level will be almost as high as his head. But he is also partly serious. That might be only a small overstatement in a city that is, on average, just two meters above sea level.

Observers say two reasons for the sinking are a rising sea level and too much pumping of groundwater. Another reason, they say, is the decision by developers to build so many high-rises because they earn quantities of money by doing so. This kind of development worries those who are concerned with the rising water level.

6 . Tropical(热带的)birds deep in Brazil’s Amazon rainforest are shrinking as the world’s climate changes. Researchers studied data for 77 tropical bird species over the past 40 years and found that all of them had lost body mass, with some species losing nearly 2% of their weight per decade.

A 2019 study of birds that had crashed into buildings in Chicago, Illinois, found that they’d lost mass over a 40—year period, but those species were migratory(迁徙的). However, why the birds changed in that way was unknown. Therefore, researchers decided to examine the records of 15, 000 non-migratory birds living in a rainforest within a few hours’ drive from Manaus in Brazil.

The average temperature of the birds’ habitat is 1℃ warmer in the wet season and 1. 65℃ warmer in the dry season compared with that in 40 years ago. What’s more, 13% more rain falls in the wet season and 15% less in the dry season. The birds have lost mass more sharply following extremely dry or wet seasons. This could be a short-term response to changes in their environment, such as a lack of rainfall causing a decline in the number of insects that the birds feed on.

“Mass is a generally good indication of body condition in birds, says Vitek Jirinec at the Integral Ecology Research Center in California, who led the study. "If they’re simply not getting enough to eat, you’d expect them to lose weight.”

Birds of the same species are generally larger at higher latitudes. The leading theory is that their smaller surface — area — to — volume ratio（表面积和体积比）allows them to better conserve heat. The opposite would help smaller species in hot climates to cool and could explain why birds are getting smaller as the climate warms, says Jirinec.

The marked physical change during just four decades show why stopping destroying trees alone won’t prevent the ongoing extinctions of animal species across the world, says Camila Gomez, a scientist who studies evolutionary changes in birds. "This study also shows how human-caused changes in climate are contributing to observed population declines in tropical birds," says Gomez.