原文

I show this because I wanna tell you a story about two teachers I had. One that I didn't like that much, the other who is a real hero to me.
I had a grade school teacher who taught geography by pulling a map of the world down in front of the blackboard. I had a classmate in the sixth grade who raised his hand and he pointed to the outline of the east coast of South America and he pointed to the west coast of Africa and he asked, “Did they ever fit together?”
And the teacher said, “Of course not. That's the most ridiculous thing I've ever heard.” That student went on to become a drug addict and a ne'er-do-well. The teacher went on to become science advisor in the current administration.
But, you know, the teacher was actually reflecting the conclusion of the scientific establishment of that time. Continents are so big, obviously they don't move. But, actually, as we now know, they did move. They moved apart from one another. But at one time they did, in fact, fit together.
But that assumption was a problem. It reflected the well-known wisdom that what gets us into trouble is not what we don't know; it's what we know for sure that just ain't so. (Mark Twain) This is actually an important point, believe it or not, because there is another such assumption that a lot of people have in their minds right now about global warming that just ain't so. The assumption is something like this. The earth is so big we can't possibly have any lasting harmful impact on the earth's environment. And maybe that was true at one time, but it's not anymore. And one of the reasons it's not true anymore is that the most vulnerable part of the earth's ecological system is the atmosphere. Vulnera-ble because it's so thin.
My friend, the late Carl Sagan, used to say, “If you had a big globe with a coat of varnish on it, the thick-ness of that varnish relative to that globe is pretty much the same as the thickness of the earth's atmos-phere compared to the earth itself.” And it's thin enough that we are capable of changing its composition. That brings up the basic science of global warming. And I'm not gonna spend a lot of time on this because you know it well.
The sun’s radiation comes in in the form of light waves and that heat up the earth. And then some of the radiation that is absorbed and warms the earth is reradiated back into space in the form of infrared radiation. And some of the outgoing infrared radiation is trapped by this layer of atmosphere and held inside the atmosphere. And that's a good thing because it keeps the temperature of the earth within certain boundaries, keeps it relatively constant and livable.
But the problem is this thin layer of atmosphere is being thickened by all of the global warming pollution that's being put up there. And what that does is it thickens this layer of atmosphere, more of the outgoing infrared is trapped. And so the atmosphere heats up worldwide. That's global warming. Now, that's the traditional explanation. Here's what I think is a better explanation.
Global Warming, or: None Like It Hot!

• You're probably wondering why your ice cream went away. Well, Susie, the culprit isn't foreigners. It's global warming. - Global... - Yeah.
  Meet Mr. Sunbeam. He comes all the way from the sun to visit earth.
• Hello, earth. Just popping in to brighten your day. And now I'll be on my way. - Not so fast, Sunbeam. We're greenhouse gases. You are going nowhere. - Oh, God, it hurts.
  Pretty soon, earth is chock-full of Sunbeams. Their rotting corpses heating our atmosphere.
• How do we get rid of the greenhouse gasses?
• Fortunately, our handsomest politicians came up with a cheap, last-minute way to combat global warming. Ever since 2063, we simply drop a giant ice cube into the ocean every now and then. - Just like Daddy puts in his drink every morning. And then he gets mad.
• Of course, since the greenhouse gases are still building up, it takes more and more ice each time. Thus, solving the problem once and for all. - But...
• Once and for all!

Q&A

1. Q: Why was the charts drawn by Professor Roger Revelle is a line up and down?
   A: Because most of the land mass is north which has many plants and can let the plants breathe in carbon dioxide when the Northen Hemisphere is tilted toward the sun.

2. Q: What does the analogy of Mr.Sunbeam and the greenhouse gases indicate?
   A: It shows that the thicker layer of atmosphere can make more of the outgoing infrared is trapped and as a result the global warming is coming.

3. Q: What opinion does the cartoon explain?
   A: It tells us about the main causes of global warming vividly and show that a lot of troubles will be brought by the global warming.

4. Q: Why is the picture which taken by the Apollo 17 the only picture of the Earth from space that we have?
   A: Because the sun was directly behind the spacecraft at that time. The Earth is fully lit up and not partly in darkness.

5. Q: Why did the grade school teacher think that the two land cannot fit together?
   A: They thought Continents are so big, obviously they don’t move.

6. Q: Why is there a lot of people thought that global warming that just ain’t so?
   A: They thought the Earth is so big. We can’t possibly have any lasting harmful impact on the Earth’s environment.

7. Q: Why did your professor choose the middle of the Pacific to send these weather balloons up?
   A: Because it was the area that was most remote.

8. Q: Why was it a wonderful time for you when you were a college student?
   A: Because, like a lot of young people, I came into contact with intellectual ferment, ideas that I'd never considered in my wildest dreams before.

9. Q: Why is there a particular problem in the Himalayas?
   A: Because 40% of all the people in the world get their drinking water from rivers and spring systems that are fed more than half by the melt water coming off the glaciers.

10. Q: According to the lecture, what is the atmosphere like to the earth?
    A: Varnish to globe

11. Q: According to the lecture, why did I think that some of the outgoing infrared radiation is trapped by this layer of atmosphere and held inside the atmosphere which is a good thing?
    A: It is keeps the temperature of the Earth within certain boundaries, keeps it relatively constant and livable.

12. Q: Who was the first man propose measuring carbon dioxide?
    A: Roger Revelle