SECTION 3
You should spend about 20 minutes on Questions 27-40
,
which are based on Reading
Passage 3 below.
Global Warming in New Zealand
A
For many environmentalists, the world seems to be getting warmer. As the nearest
country of South Polar Region, New Zealand has maintained an upward trend in its
average temperature in the past few years. However, the temperature in New Zealand
will go up 4°C in the next century while the polar region will go up more than 6°C .The
different pictures of temperature stem from its surrounding ocean which acts like the air
conditioner. Thus New Zealand is comparatively fortunate.
B
Scientifically speaking, this temperature phenomenon in New Zealand originated from
what researchers call ” SAM (Southern Annular Mode), which refers to the wind belt that
circles the Southern Oceans including New Zealand and Antarctica. Yet recent work has
revealed that changes in SAM in New Zealand have resulted in a weakening of moisture
during the summer, and more rainfall in other seasons. A bigger problem may turn out to
be heavier droughts for agricultural activities because of more water loss from soil,
resulting in poorer harvest before winter when the rainfall arrive too late to rescue.
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P a g e
C
Among all the calamities posed by drought, moisture deficit ranks the first. Moisture
deficit is the gap between the water plants need during the growing season and the water
the earth can offer. Measures of moisture deficit were at their highest since the 1970s in
New Zealand. Meanwhile, ecological analyses clearly show moisture deficit is imposed
at different growth stage of crops. If moisture deficit occurs around a crucial growth stage,
it will cause about 22% reduction in grain yield as opposed to moisture deficit at vegetative
phase.
D
Global warming is not only affecting agriculture production. When scientists say the
country’s snow pack and glaciers are melting at an alarming rate due to global warming,
the climate is putting another strain on the local places. For example, when the
development of global warming is accompanied by the falling snow line
,
the local skiing
industry comes into a crisis. The snow line may move up as the temperature goes up,
and then the snow at the bottom will melt earlier. Fortunately, it is going to be favourable
for the local skiing industry to tide over tough periods since the quantities of snowfall in
some areas are more likely to increase.
E
What is the reaction of glacier region? The climate change can be reflected in the glacier
region in southern New Zealand or land covered by ice and snow. The reaction of a glacier
to a climatic change involves a complex chain of processes, Over time periods of years
to several decades, cumulative changes in mass balance cause volume and thickness
changes, which will affect the flow of ice via altered internal deformation and basal sliding.
This dynamic reaction finally leads to glacier length changes, the advance or retreat of
glacier tongues. Undoubtedly, glacier mass balance is a more direct signal of annual
atmospheric conditions.
F
The latest research result of National Institute of Water and Atmospheric (NIWA)
Research shows that glaciers line keeps moving up because of the impacts of global
warning. Further losses of ice can be reflected in Mt. Cook Region. By 1996
,
a 14 km
long sector of the glacier had melted down forming a melt lake (Hooker Lake) with a
volume. Melting of the glacier front at a rate of 40 m/yr will cause the glacier to retreat at
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