Arctic Meltdown

The 2015/16 cool season was quite exceptional in the Arctic, which is heading into uncharted territory this summer.  Both the National Snow and Ice Data Center and Mashable reporter Andrew Freedman provide excellent summaries, so I'll only hit some highlights here.

As can be seen from the chart below, the arctic sea-ice extent tracked at or near all time lows in the satellite era for the entire cool season.  Since late April it has been well below anything observed previously.

Source: NSIDC

If we look at just the average Arctic sea-ice extent for May, we see a bit more clearly how anomalous this May is, with a sea-ice extent of around 12 million square kilometers, about 2 million lower than 1979.

Source: NSIDC

The graph above shows considerable year-to-year variability, but also the long-term decline associated with global warming.  Record lows occur when the natural climate variability favors conditions conducive for limited ice growth in the cool season and/or considerable ice loss in the warm season.  While this can sometimes be followed by a temporary recovery, it is safe to say that we are moving toward a dramatically transformed Arctic.