Answer and Explanation:
SUN: What's that I see in this planet's atmosphere? Where does all this pollution come from?
COAL: I apologize, but I believe it is my fault.
SUN: Ah, it is you, Coal? Still being used, I see?
COAL: That's right... Still waiting to retire. You'd think human beings would have moved on by now.
SUN: True. Do they not know how harmful you can be?
COAL: They do know. Some countries did work hard to get rid of their dependency on me to generate energy and heat. But there are places where I am still very much used.
SUN: That is a shame. I shine everywhere, indiscriminately. If only they would harness my power.
COAL: That is what I'm hoping for as well. I see no cleaner way to generate energy than using you, Sun.
WATER: But how about me?
SUN: Sister Water, have you been listening?
WATER: Yes, for I wanted to speak to Coal. His mining has got much of me contaminated. I have become acidic in several places of the world due to the mining of Coal.
COAL: I again apologize. As I was saying to Sun, I have been waiting for humankind to stop using me, but they just don't seem able to do it.
WATER: I see. I understand.
SUN: How is your role in generating energy coming, Water?
WATER: As powerful as ever. Several countries depend on me. There are some issues, though.
COAL: With you as well?
WATER: Oh, yes. I may be clean, but man does a dirty job when building dams and hydroelectric plants. The impact on the environment is not pretty.
SUN: What a shame!
WATER: But I do have hope. Men from different countries have been gathering, meeting, and discussing these issues. To my mind, you are the future, Sun.
COAL: Yes, I agree!
SUN: I hope so. I shine for free. My power is constantly available and will not end for billions of years. I hope humankind will learn to rely on me more!