First, a glass of water does not stay at 0C until all the ice melts. If it did, the ice would never melt under the surface, major duh here since it melts faster. Aren't you an engineer?
Yes I am and yes it does. Sure there will be very minor incremental temperature differences throughout the liquid but basically the water stays at a *relatively* constant temperature and the energy of added heat to the system is taken up by the energy (80 cal/g) of the solid to liquid phase change.
you'll look like a real dumbass for having bought the farm over it.
And if 2010 is the new warmest year on record?
You might argue that those two climate shifts were regional rather than global,
I thought that *was* what I argued.
If you are blowing off major century-scale temperature shifts as "weather",
I'm not "blowing off" century-scale temperature shifts major or otherwise. Perhaps the weather/climate distinction is not the best terminology for this precise circumstance but if in fact the MWP was simply a redistribution of heat from one part of the globe to another part of the globe due to some change in the thermal transport system then it's clear that the effect of the global mean temperature would not be all that great.
The bottom line is that regardless of being able to grow grapes in England during the MWP they can grow grapes in England right now.
I made no argument that the MWP and LIA should be averaged out over time only that they should be averaged out over the area of the globe. This is merely a restatement of the fact that if it's 50C in the sahara and -10C in Boston that neither proves nor disproves AGW.
Also, if they are arguing that those two events were regional and disappear when averaged globally, it means there were regions with statistically similar patterns in the reversed order, right?
Correct assuming that the global temperature stayed totally flat which no one is doing. Only that the temperature increase that existed over a limited area, say the north atlantic ocean as a rough guess, needs to be averaged over the area of the planet. Even granting that this area encompasses 1/4th of the globe (a gross over estimate) that implies that the affect of any temp increase is 1/4th of what actually occured locally.
The bottom line is that I do not find it incredulous to believe that global mean temperatures today exceed *global mean temperatures* of the MWP, even though temps in the region then may in fact be exceeding temps in the region now. That's all the hocky stick is really saying.
I would be more inclined to accept the ipcc 'hockey stick' graph if it included the original English data as at least one of the data sets.
They effectively were. We've seen the effect of the MWP and LIA in the GISP2 ice core record and that was most certainly a part of the data set.