Answer:
the loss of other alternatives when one alternative is chosen.
The sun is a vital part of the earth, so if it changes energy levels, it will clearly have an affect on the earth. If the energy increases, it'll most likely dry out the grass and melt the snow, etc. If it decreases, the snow could freeze and change the climate.
Unsure of the page number, but.. The word, “aloof” in the book, “Mice and Men”, can be found on chapter 4.