The NASA thing is just how much the ice retreats during summer each year, not that it's permanently melted. I think there are some indications it's recovered a bit lately, though it's hard to tell which claims are more credible. In any case that doesn't prove there's global warming or that it's produced by human caused CO2. The only thing that "proved" that were the computer climate models, and they've been shown to have been manipulated, and don't predict current climate, which is what the der Spiegel link I posted is talking about.
Another area of debate is whether ice in other places is increasing or decreasing. Until recently it's been thought Antartica is increasing, now may be it's decreasing in some places but not in others, and I think those results are preliminary anyway. I think this thing needs to get a lot less political before the scientific evidence is credible again.