Carbon dioxide and other naturally occurring gases in the earth's atmosphere create a natural greenhouse effect by trapping and absorbing solar radiation. These gases act as a blanket and keep the planet warm enough for life to survive and flourish. The warming of the earth is balanced by some of the heat escaping from the atmosphere back into space. Without this compensating flow of heat out the system, the temperature of the earth's surface and its atmosphere would rise steadily.
Scientists are increasingly concerned about a human-driven greenhouse effect resulting from a rise in atmospheric levels of carbon dioxide and other heat-trapping greenhouse gases.
The man-made greenhouse effect is the exhalation of industrial civilization. A major contributing factor is the burning of large amounts of fossil fuels-coal, petroleum, and natural gas. Another is the destruction of the world's forests, which reduces the amount of carbon dioxide converted to oxygen by plants. Emissions of carbon dioxide, chlorofluorocarbons, nitrous oxide, and methane from human activities will enhance the greenhouse effect, causing the earth's surface to become warmer. The main greenhouse gas, water vapor, will increase in response to global warming and further enhance it.
There is agreement within the scientific community that the buildup of greenhouse gases is already causing the earth's average surface temperature to rise. This is changing global climate at an unusually fast rate. According to the World Meteorological Organization, the
earth's average temperature climbed about 1 degree F in the past century, and nine of the ten warmest years on record have occurred since 1990. A United Nations panel has predicted that average global temperatures could rise as much as 10.5 degrees F during the next century as heat-trapping gases from human industry accumulate in the atmosphere.
What are the potential impacts of an enhanced greenhouse effect? According to estimates by an international committee, North American climatic zones could shift affect all sectors of society. In some areas, heat and moisture stress would cut crop yields, and traditional farming practices would have to change. For example, in the North American grain belt, higher temperatures and more frequent drought during the growing season might require farmers to switch from corn to wheat and to use more water for irrigation.
Global warming may also cause a rise in sea level by melting polar ice caps. A rise in sea level would accelerate coastal erosion and inundate islands and low-lying coastal plains, some of which are densely populated. Millions of acres of coastal farmlands would be covered by water. Furthermore, the warming of seawater will cause the water to expand, thus adding to the potential danger.
Global warming has already left its fingerprint on the natural world. Two research teams recently reviewed hundreds of published papers that tracked changes in the range and behavior of plant and animal species, and they found ample evidence of plants blooming and birds nesting earlier in the spring. Both teams concluded that rising global temperatures are shifting the ranges of hundreds of species-thus climatic zones-northward. These studies are hard evidence that the natural world is already responding dramatically to climate change, even though the change has just begun. If global warming trends continue, changes in the environment by pollinating plants, dispersing seeds, and controlling insect populations; thus, changes in their populations will reverberate throughout the ecosystems they inhabit.
Question 1. According to the passage, how do carbon dioxide and other greenhouse gases affect the earth- atmosphere system?
A. They collect solar radiation that warms the earth's surface.
B. They create the conditions for new forms of life to emerge.
C. They cause heat to flow from the atmosphere into space.
D. They decrease the amount of oxygen in the atmosphere.
Question 2. All of the following are contributing factors to global warming EXCEPT A. The burning of coal and petroleum
B. The loss of forest lands
C. The conversion of carbon dioxide to oxygen D. The buildup of water vapor in the atmosphere.
Question 3. The word “enhance” in paragraph 2 is closest in meaning to
A. Strengthen B. Counteract C. Stabilize D. parallel Question 4. What can be inferred from paragraph 3 about global climate change?
A. Climate change will have both positive and negative effects on human society.
B. It is difficult to predict the effects of climate change over the next century.
C. International organizations have been studying climate change only since 1990.
D. Climate change is likely to continue as long as heat-trapping gases accumulate.
Question 5. According to paragraph 4, what is one effect that climate change could have on agriculture in North America?
A. Return to more traditional methods of farming B. Movement of farms to the northernmost regions C. Changes in the crops that farmers grow
D. Less water available for irrigating crops
Question 6. The word “inundate” in paragraph 5 is closest in meaning to
A. Cover B. Reduce C. Move D. create
Question 7. Why does the author use the word “fingerprint” in paragraph 6?
A. To show that hundreds of fingerprints were examined B. To introduce conclusive evidence of global warming C. To describe a method used by two research teams D. To suggest that people do not cause global warming Question 8. The word “they” in paragraph 6 refers to
A. Teams B. Papers C. Species D. birds
Question 9. The word "hard” in paragraph 6 is closest in meaning to
A. difficult B. real C. contradictory D. secret
Question 10. What evidence does the author give that climatic zones shifted northward?
A. Solar radiation escapes from the atmosphere back into the space.
B. The water in the ocean expands as it gets warmer.
C. Plants boom and birds build nests earlier in the spring.
D. Birds no longer pollinate plants or control insect populations
ĐÁP ÁN
1. A 2. C 3. A 4. D 5. C 6. A 7. B 8. A 9. B 10. C
GIẢI THÍCH CHI TIẾT Question 1: Đáp án A.
Key words: carbon dioxide, greenhouse gases, earth-atmosphere Clue: Đoạn đầu tiên của bài khóa
“Carbon dioxide and other naturally occurring gases in the earth's atmosphere create a natural greenhouse effect by trapping and absorbing solar radiation. These gases... keep the planet warm enough for life to survive and flourish.”: Khí CO2 và các khí nhà kính khác trong khí quyển Trái Đất tạo ra hiệu ứng nhà kính tự nhiên bằng cách giữ và hấp thụ bức xạ mặt trời.
Những khí này... giữ cho Trái Đất đủ ấm để sự sống tồn tại và nảy nở.
Câu hỏi: Theo bài khóa, khí CO2 và các khí nhà kính khác ảnh hưởng như thế nào đến bầu khí quyển Trái Đất?
Phân tích:
A. They collect solar radiation that warms the earth's surface: Những khi này tích tụ bức xạ
mặt trời làm ấm bề mặt Trái Đất: Đúng, trùng với thông tin Clue.
B. They create the conditions for new forms of life to emerge: Những khí này tạo điều kiện để những thể sống mới xuất hiện: Sai vì bài đề cập đề duy trì sự sống (sẵn có) và làm chúng sinh sôi nảy nở.
C. They cause heat to flow from the atmosphere into space: Những khí này làm hơi nóng từ bầu khí quyển thoát ra ngoài vũ trụ: Sai vì nhiệt sẽ hấp thụ lại ở Trái Đất khiến Trái Đất ấm lên.
D. They decrease the amount of oxygen in the atmosphere: Những khí này làm giảm lượng oxy trong không khí: Sai, không có thông tin.
Vậy đáp án đúng là A. They collect solar radiation that warms the earth's surface.
Question 2: Đáp án C.
Key words: contributing factors, EXCEPT
Clue: Đoạn thứ 2: “A major contributing factor is the burning of large amounts of fossil fuels-coal, petroleum, and natural gas. Another is the destruction of the world's forests...
Emissions of carbon dioxide... will enhance the greenhouse effect...The main greenhouse gas, water vapor, will increase in response to global warming and further enhance it.”
Những cụm in đậm trong Clue là các yếu tố góp phần tạo ra hiện tượng nóng lên toàn cầu.
Câu hỏi: Tất cả những yếu tố sau góp phần tạo ra hiện tượng nóng lên toàn cầu NGOẠI TRỪ?
Phân tích:
A. The burning of coal and petroleum: Sự cháy của than và dầu hỏa: Có xuất hiện trong Clue B. The loss of forest lands: Mất rừng: Có xuất hiện trong Clue (destruction of the world's forests)
C. The conversion of carbon dioxide to oxygen: Chuyển hóa khí CO2 sang O2: Không xuất hiện
D. The buildup of water vapor in the atmosphere: Sự tích tụ hơi nước trong không khí: Có xuất hiện trong Clue