vaclav smil at the university of manitoba is pretty much awesome when it comes to straight-talking about energy futures. he wrote in to nature this week and had this to say after bashing the IPCC scenarios:
"…the rise of atmospheric CO2 above 450 parts per million can be prevented only by an unprecedented (in both severity and duration) depression of the global economy, or by voluntarily adopted and strictly observed limits on absolute energy use. The first is highly probable; the second would be a sapient action, but apparently not for this species."
his latter point is well taken, but given the recent experience in juneau, and other experiences in brazil, it seems to be the case that we can vastly ramp down consumption if required. whether this can be sustained for long periods of time is, perhaps, another story.