Someone tell me...what exactly IS the optimal temperature for the earth?
Optimal temperature for the earth... there isn't one.
Optimal temperature for the species to which you presumably belong...Species: Homo sapiens (endothermic)
Normal Body Temperature: 37.0 C
LCT: 27.0 C
UCT: 32.0 C
27.0C to 32.0C (environmental) is the thermal neutral range of our species. In that range is where metabolic rate is minimal, and animal is at basal metabolic state.
LCT= lowest critical temperature. Lower than this, each individual passes into threshold points for hypothermia
UCT=upper critical temperature. Higher than this, each individual passes into threshold tolerances for hyperthermia
Hate to bring biology into it, but asking what temperature is right for the earth is the wrong question.
You figure out the difference.