Quote Originally Posted by DuncanONeil View Post
But that then gives rise, again, to the question; "what is the proper temperature for the planet?"
Sorry and with all due respect, but that is total rubbish. There is no 'proper' temperature for the planet. The planet gives a rat's ass about its temperature. We as a species, don't, or shouldn't, because large parts of our civilization pretty much depend on more or less the temperature we have now.