While satellite images can’t distinguish temporary plants like grasses that come and go with the rains, ground surveys suggest recent vegetation change is firmly rooted. In the eastern Sahara area of southwestern Egypt and northern Sudan, new trees—such as acacias—are flourishing, according to Stefan Krpelin, a climate scientist at the University of Cologne’s Africa Research Unit in Germany.
“Before, there was not a single scorpion, not a single blade of grass,” said Krpelin, who has studied the region for two decades.“Now you have people grazing their camels in areas which may not have been used for hundreds or even thousands of years. You see birds, ostriches, gazelles coming back, even sorts of amphibians coming back,” he said.“The trend has continued for more than 20 years. It is indisputable.”
An explosion in plant growth has been predicted by some climate models.For instance, in 2005 a team led by Reindert Haarsma of the Royal Netherlands Meteorological Institute in De Bilt, the Netherlands, forecast significantly more future rainfall in the Sahel.The study in Geophysical Research Letters predicted that rainfall in the July to September wet season would rise by up to two millimeters a day by 2080.
Satellite data shows “that indeed during the last decade, the Sahel is becoming more green,” Haarsma said.Even so, climate scientists don’t agree on how future climate change will affect the Sahel: Some studies simulate a decrease in rainfall. “This issue is still rather uncertain,” Haarsma said.
Max Planck’s Claussen said North Africa is the area of greatest disagreement among climate change modelers.Forecasting how global warming will affect the region is complicated by its vast size and the unpredictable influence of high-altitude winds that disperse monsoon rains, Claussen added. “Half the models follow a wetter trend, and half a drier trend.”
6. According to the first paragraph, global warming is supposed to have the following impacts on Africa EXCEPT ________.
A. water deficiency
B. distress
C. desertifications
D. more grasses and lakes
7. According to Martin Claussen, what is the main cause of the increased vegetation in deserted areas?
A. The climate models are more changeable.
B. Hot air would be more capable to hold humidity. C. Many trees have been planted recently.
D. The grasses are temporarily appeared with the rains.
8. What is the role of the sixth paragraph in the development of the topic? A. To make a transition to a new topic.
B. To work as a book to the following paragraphs.
C. To provide a contrast to the preceding paragraphs.
D. To offer supporting evidence to the preceding paragraphs.
9. The underlined sentence “… North Africa is the area of greatest disagreement among climate change modelers” in the last paragraph suggests that ________.
A. half of the area will follow a wetter trend, while half a drier trend
B. the scientists in North Afrca hold different opinions in climate models
C. it is not easy to predict how the climate change influences the district
D. there are different climate models to be built in North Africa
10. What are the climate scientists’ attitudes towards the influence of climate change on the
deserted areas?
A. Definite B. Dubious
C. Serious D. Negative
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