I've got a pretty heavy energy efficiency background and I can say that even though I'm not a man made global warming nut, it makes sense to a point, to make things as efficient as you can afford. I'm all about conserving resources, but I'm also all about saving money. I'm about to go R-60 on my attic insulation, my original insulation is pretty badly settled, it's around an R-22 now, so it's time, and my electric bill is showing it. We already have radiant barrier, and the house is only 7 years old. I'd say our electric bill has gone up 20% and our kWh rate has gone down, so it may be 25% more kWh usage now. We're all electric with no gas available.