The hole in the Earth's ozone layer (臭氧层)has until now protected Antarctica from the worst effects
of global warming. But scientists have warned that as the hole closes up in the next few decades,
temperatures on the continent could rise by around 3C on average, with melting ice contributing to a
global sea level increase of up to 1. 4 metres.
In the past decades the western Antarctic has seen rapid ice loss as the world has warmed,but the
other parts of the continent have, paradoxically, been cooling,resulting in a 10% increase in ice in the seas
around the region. This is because the hole in the ozone layer has increased cold winds in Antarctica,
making much of the continent surface colder than usual.
But now that the gasses that cause the ozone hole have been banned, scientists expect the hole to
repair itself within the next 50 to 60 years. By then the cooling effect will have faded out and the
Antarctic will face the full impact of global warming. This means an increase in average air temperatures
of around 3? and a reduction in sea ice by around a third.
The biggest threat to the continent comes from warming seas. Robert Johnson, a scientist who
monitors Antarctica ice sheets, said, "The ice sheets in Antarctica are hundreds of metres thick. But
once warm ocean waters start flowing underneath, the ice will begin thinning and could break up very
quickly. " Thinning ice sheets cause ice to break away from the continent and to melt even faster.
Escaping ice from western Antarctica has already resulted in a 10% rise in global sea level in recent
decades.
Johnson believes that international action to reduce global warming is required immediately or it may
be too late. "Everything is connected-Antarctica may be a long way away but it is an important part of
the Earth's system," said Johnson. "It contains 90% of the world's ice, 70% of the world's fresh water
and that is enough, if it melts completely,to raise sea levels by 63 metres. "
Even in a worsecase situation scientists don't expect the ice to entirely disappear,but predict that,
because of the melting ice sheets,average sea level rise will be around 1. 4 metres higher by the end of
the century.
1. The underlined word "paradoxically" (in Paragraph 2) most probably means "________".
A. rapidly
B. approximately
C. contradictorily
D. apparently
2. What is the effect of the hole in the ozone layer on Antarctica?
A. It is making much of the continent colder.
B. It is causing the ice to melt faster.
C. It is making the effects of global warming in the region worse.
D. It is reducing the amount of water in Antarctica.
3. What do scientists think is the biggest danger facing Antarctica?
A. Rising sea levels.
B. Warming sea water temperature.
C. Water pollution.
D. Growing ice sheets.
4. Which of the following is TRUE according to the passage?
A. Antarctica contains most of the world's fresh water.
B. The average temperature has increased by 3 degree centigrade in recent decades.
C. Antarctica is currently experiencing the full effects of global warming.
D. Ten percent of Antarctica's ice has already been lost.
5. The BEST title for the passage is ________.
A. Our planet in danger
B. Antarctica melting away
C. Action plan to save Antarctica
D. Let's save the ozone layer
