Your answer to that question is supposed to have some deep meaning on how you view the world. Half empty is supposed to be a pessimistic view of the world, where as half full is supposed to show you are optimistic.
Bunch of garbage.
If the glass was filled half way the glass is half full. If half of a full glass was emptied then the glass is half empty. If you come across a glass and don’t know either of the previous all you can say is the class contains half of what it is capable of containing, nothing more.
What does that have to do with temperature changes? Lots.
I often post in the Globe and Mail when they run some story about AGW. In the latest round I pointed someone who was a supporter of AGW to this site to show them that summer temps have been cooling while winter temps have not gotten as cold. He accused me of misrepresenting what is happening.
“More heat is being added in the winter” was his claim, as if adding more heat is bad, which is the mantra of AGW. My reply to him was that it depended on how you looked at it. I asked him if the glass is half full or half emptied.
The analogy goes like this. The world is supposed to be summer all year long. That’s what it was for almost all of geological time in the past 500 million years at least, punctuated by a few rare ice ages. Thus in the temperate zones there was no winters, no seasons. And a new paper just published showed those times were great for the biota. If anything, having winter seasons was bad for the biota in those areas. See paper here. So one can argue that going into winters means the planet is losing vital heat.
So the premise is this, since going into winter LOSES heat that should have been retained (emptying the glass) then for it to not get as cold in the winter means not as much of that vital heat is lost (not emptying the glass as much).
Of course he not only refused to see temperature in that way, but he also refused to answer how a milder winter can be bad. Only in the world of dogma does one not see alternative possible ways of viewing the same phenomenon. In this person’s mind the glass is supposed to be empty, and adding to it, adding ANY heat to the atmosphere, including heat that was lost, is a priori bad.