When most main sequence stars exhaust their hydrogen supply, they become giants. Yet on the diagram, there are not many stars between the main sequence and the giants. What would explain this fact?

the correct answer to this question is #5

carbon traps heat so more of it makes it hotter causing global warming. during the ice age carbon levels in the atmosphere were low so it got very cold. so the common things between them is carbon levels in the atmosphere.

answer; projective;