Heretics/Lomborg: We talked briefly of the ice melt several weeks ago, noting that the melt was dramatic, but not necessarily unprecedented (i.e., some evidence from the 50s shows similar melts). The thing is, if it is a cyclical change, there isn't any proof -- since we haven't really been measuring long enough to detect geological-scale changes. However, if it is a man-made effect, we should be able to see trends in our relatively short-term records. But any attempt to find clear trends has failed miserably, and attempts to extrapolate from implied trends have had no luck in predicting actual climate changes. Put simply, there isn't enough evidence to get worked up. As you know, I'm a practical green (and I think Lomborg still is one, too); I like low-emission vehicles, though I'm inclined to drill for oil in Alaska, if only to stick it to OPEC a bit. I like the idea of clean air and water, and being able to eat fish without worrying about toxins and heavy metals. But the global warming thing I don't really see as a threat, and there are a lot of better places for a practical green to advocate spending resources now.