How Many Empire State Buildings Does the Arctic Lose Each Decade?

Image source.

Right around this time last year, we started hearing an awful lot of crowing from deniers about Arctic sea ice extent making some record recovery they dreamed up. It's really difficult for me to understand how the 6th lowest minimum on record is something to celebrate, even if you pretend the climate isn't changing at all and/or due to our emissions. I mean, I know deniers are screwballs and everything, but I thought maybe they'd at least have enough common sense not to intentionally defeat their own ignorant purposes by trumpeting the sixth lowest minimum like it proves the planet stopped warming or something.

Obviously, they try to cherry-pick the ice conditions at either pole which suit their strange denial-fest, and the challenge appears a bit beyond them anymore. They have to pretend the realities of the downward trend in global sea ice extent don't exist, and stick their fingers in their ears especially aggressively over the volume of land and sea ice lost in the Arctic and Antarctic annually. Volume, to my mind, is a much better gauge of the effects of global warming, because ice can spread thin, have greater coverage (extent), and look like it's increasing overall due to many factors, some of which are caused by climate change itself (scroll down to the "Antarctica’s positive trend in sea ice extent" section of this NSIDC link for further explanation).

Personally, I try to pay more attention to volume data, and here's what sea ice volume has been doing in the Arctic for the past 35 years or so:



Look at the "Anomaly Trend" figure in the lower left of that image. 3,000 km^3 +/- 1,000 km^3 lost every decade. Approximately three thousand cubic kilometers of ice vanishes every ten years. That's three trillion cubic meters. To give you some perspective, the Empire State building is about 1 million cubic meters in volume, so the Arctic loses 3 million Empire State Buildings worth of sea ice each decade, or three hundred thousand per year.

To further illustrate how much ice goes missing, let's very roughly approximate the volume of Mt. Everest using the formula for the volume of a cone (I did say very roughly):

3.1416 * 22km^2 * (9km/3) = 4561.59 km^3

The Arctic loses around two-thirds to three-quarters a Mt. Everest worth of sea ice every ten years.