Oct 06 2009
Chapter 3 Study Guide Question #6 — Describe the “fate” of most solar energy that reaches the Earth.
First of all, I apologize this post is so late! I totally understand if no one responds! Okay…I understand the different “forms” solar energy reaches the earth (electromagnetic waves–UV radiation, visible light, and heat or infrared radiation). I also understand that 95% of the harmful radiation from the sun is absorbed by the ozone layer. I am confused when our book states, “Of the total solar radiation intercepted by the earth, about 1% reaches the earth’s surface.” It seems like there is a 4% missing; I know it hasn’t gone “missing,” but where has this 4% of solar energy gone!? Does this 4% simply exist as light/heat in our atmosphere and never specifically reaches the earth’s surface by directly touching/making contact with land? I’m probably way over thinking all of the %, but if someone could correct me that would be awesome! Thanks, guys! Good luck with your studying tonight! =)
Great question. No concern for tomorrow. The electromagnetic spectrum is disrupted in many ways as it is emitted from the sun. We’ll deal with the “fate” of all the energy eventually. For now, appreciate that very little reaches the Earth (but just enough for life), and that when it arrives produces rather inefficiently store it in glucose. Then, most of that is wasted as heat by the fourth trophic level (2nd Law of Thermodynamics)!