Juan,
If I understand what you say, volume loss has been much greater than extent loss? You say ~50% off what volume was 30 years ago? I have questions: If I have an ice cube in my drink that is 50% smaller than one in a glass next to it, that smaller ice cube, in same warm conditions, should melt out exponentially faster than the larger one, yes? If so much ice has been lost up there, how did the ice extent recover so well from its horrid early season state during the height of the melt season? I need help here, but did not even the PIOMASS show a decent recovery this summer too? It doesn't make sense to me all these claims I constantly hear about volume loss compared to extent.