4 . Parts of East Asia could see “rivers in the sky” form due to climate change, bringing record-breaking levels of rainfall with them, a new study has revealed.

The team, from the University of Tsukuba, Japan, have already seen clear signs of global warming hitting parts of the country, so they wanted to see how bad things could get. “It’s been becoming more and more clear that global warming means more than just warmer temperatures,” they wrote.

One particularly-damaging extreme weather event is an increase in rainfall to unexpected and unprecedented (前所未有的) levels, which can result in flooding. To help predict rainfall events, researchers looked to one of the causes — the interaction of atmospheric rivers with mountain ranges.

“As the name suggests, atmospheric rivers are long, narrow bands of concentrated water vapour flowing through the atmosphere,” the team explained. “When one of these bands meets a barrier, such as a mountain range, it can produce extreme levels of rainfall or snowfall.”

Parts of East Asia have been subjected to (遭受) an increasing number of damaging, extreme weather events over the past decade.

To understand the impact, the team used high-resolution global atmospheric circulations model simulations (模拟) that virtually re-create the conditions in the atmosphere. They then looked at other regional climate models, comparing simulations based on real, meteorological data (气象数据) from 1951 to 2010 to predictions for 2090.

Authors used the climate scenario that would result in 4℃ of warming, compared to preindustrial levels — which is significantly more than 2℃ target set as part of Paris Climate Agreement.

First author, Professor Yoichi Kamae, said that their simulations predict strengthened water vapour transport, as well as increased rainfall at unprecedented levels. In simulations the greatest amounts of atmospheric river-related rainfall occurred on the southern and western slopes of mountains in East Asia, including in Japan, the Korean Peninsula, and northeastern China. They had to limit the study to East Asia due to computer time and processing limitations, but predict it would apply to other regions around the world.

1. What’s the possible consequence of the global warming?

A．It contributes to polluted air.

B．It leads to hot and rainy climate.

C．It only results in the rise of temperature.

D．It causes the destruction of more species.

2. The author wrote Paragraph 4 to ________.

A．describe the new study

B．introduce atmospheric rivers

C．analyze the cause of rainfall

D．warn people of global warming

3. How is the research carried to know the effect?

A．By comparison.	B．By discussion.
C．By examples.	D．By explanation

4. What’s the attitude of Professor Yoichi Kamae toward their simulations?

A．They are risky.	B．They are valueless.
C．They are perfect.	D．They are convincing.