Brian, so now you're hitting the reset button on all the years of exposure to the science behind AGW both here and other places, and now you want Ray to explain why it's a bad thing?!? One more time?!?

Have you really forgotten? Or maybe you're operating under the misapprehension that the kind of warming we're discussing here is akin to being on a car ride with family, and we're trying to decide if we want the heater set for 73 degrees or 74 degrees?

Maybe that's what got you hung up on accepting AGW - ie "what's so bad about a few degrees more?" It's not a matter of our physical comfort when we handle 20 degree swings on a day. The problem isn't that. The Earth and its systems can handle daily, weekly, and seasonal changes, because weather is chaotic. That we know, Brian. When we have the decades' long pumping of greenhouse gases into that same system, the trends over decades begin to trend upward. More extreme weather events now (record highs and lows), but those records highs are starting to outweigh the record lows, both in numbers and impact.