S e c o n d e d I t I o n 1 Reading for the Real World 1

Extinction of Dinosaurs
Discussion
Discuss the following questions.
1.
Scientists generally agree that the Earth is currently in a warming phase. 
What are some of the advantages and disadvantages of global warming?
2.
What are some other ways that humans could face extinction? 
How can these possible extinction scenarios be prevented?
Track 18

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Vocabulary Preview
 
Match each word or phrase with the correct definition.
1.
consequence 
a.
a meeting between heads of governments or officials
2.
delegate 
b.
unlikely; not very possible
3.
improbable 
c.
something given off or released into the air
4.
emission 
d.
a person acting as a representative
5.
protocol 
e.
a result
6.
summit 
f.
a first draft from which a treaty is prepared 
Pre-Reading Questions
Think about the following questions.
1.
What produces greenhouse gases?
2. 
Why is the greenhouse effect bad?
3. 
Is the yearly rate of air pollution in your country now better or 
worse than the rate in 1990?
A Plan to Curb 
Greenhouse Gases
 
E n v i ro n m e n t a l I s s u e s
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A Plan to Curb Greenhouse Gases
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A 
s sunlight shines on the Earth, solar radiation is absorbed and then 
radiated
back into space as thermal radiation (heat). However, some 
of this heat is trapped by gases in the atmosphere. The trapped heat 
increases the temperature of the Earth’s surface and atmosphere. The process is 
similar to the way a greenhouse is kept warm. The Earth’s natural levels of water 
vapor and other gases produce this greenhouse effect, making life on Earth 
possible. However, some scientists are now predicting that higher levels of 
certain greenhouse gases are causing temperatures to rise beyond natural limits.
Since the beginning of the industrial age, carbon dioxide (CO
2
) has been 
building up in the Earth’s atmosphere as a result of the burning of