Arctic sea ice extent up from last year, but still far from recovering

Amid all the talk of Arctic sea ice not getting down to as low as it did last year, and how this is apparently a 'record recovery', one fact seems to have slipped through the cracks. The extent of the ice — how much ocean surface it covers — may not have reached another record low, but the volume of the ice — how much ice is really there — was already at a record low at the start of the summer, showing that we are far from any 'recovery'.

Right about this same time last year, records of Arctic sea ice gave us a dire warning of what was to come, as the extent of the ice reached stunningly low levels — lower than anything we'd seen so far. This year, the ice extent 'only' got down to the 6th lowest level on record, which is now being widely proclaimed as a 'record recovery' by those who try to deny that our activities are warming the planet and changing the climate at a record pace.

This is far from a 'recovery', though, as that word implies that things are getting better. The extent of the sea ice this year may be higher than last year, but we saw this same thing happen in 2007, when we hit the last extreme record low. For 2008 and 2009, there was this same supposed 'recovery', and then the extent of Arctic sea ice plummeted to another all-time record low just three years later.

What's really suffering is the volume of the ice. Looking at how much ocean surface the ice covers is a good start, but if you don't count in the thickness, you don't know how much there is. According to the European Space Agency's Cryosat mission, the thickness of the ice reached a record low level at the start of the summer this year. Therefore, even though the maximum extent of the ice in March was the 'only' sixth lowest maximum on record, the actual amount of ice was far lower than that.

The ESA produced a video of Cyrosat readings over the past three years, showing just how thin the ice has been getting:

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The dangers of thin ice are high enough on the small scale, as you don't walk out onto any frozen pond or lake unless you know the ice is thick enough to hold your weight. The danger of thin ice on the large scale are much greater. The thinner the ice is, the less it takes to break that ice up and melt it. It took some extreme weather events, on top of the warming of the ocean and atmosphere from greenhouse gas emissions, to give us last year's extreme melt, but with the hit that the volume of ice took, it may not take as much, and it may not take another five years, for us to again plunge to another record low.

(Photo courtesy: Reuters/Jessica Rinaldi)

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