Quite often when discussing arctic sea ice, people refer to the area of the sea ice. It would seem, to me, that it is actually the volume that is what is important as it tells you how much ice is being lost and hence how much energy is being used to melt the ice (and then how much is released when it refreezes). The image below is one I found that shows the change in sea ice volume since 1979. What is important, in my view, is that both the minimum and maximum are changing with time. If the maximum remained constant then the net amount of energy absorbed (when it melts) would be the same – on average – as the amount released (when it refreezes). That both are decreasing with time tells us that net amount of energy being absorbed is increasing with time. This, of course, also ignores the decrease in albedo due to the reduction in ice cover and hence the enhanced absorption by the now uncovered sea water.
What motivated me to write this was an interesting video illustrating the change in the minimum sea ice volume. Quite dramatic, in my opinion.