The September PIOMAS Arctic sea ice volume data for is now available, which includes the minimum ice volume for 2012 (3263 km^3 on Sept 16). I have now updated my 2011 exponential and quadratic fits & extrapolations to include these latest 2012 data.

The result: almost no change in the fit parameters. The exponential fit goes to zero summer ice volume in 2015; the quadratic in 2017.

These extrapolations are now in the very near future and don't allow for much slack in the estimates. More importantly, they aren't changing much from year to year.

At this time, it's looking increasingly certain that the Arctic summer sea ice will vanish by 2016 +/- 1 yr.

Even the maximum winter ice volume fits don't change much. The exponential fit still extrapolates to zero winter ice by 2028; the quadratic to zero winter ice by 2040. So my best estimate is: no Arctic winter sea ice at all by 2034 +/- 6 yrs.

The exponential fits to the PIOMAS data are here:
http://www.ap.smu.ca/~pbennett/climate/piomas_icevolexpfit_2...

and the quadratic fits here:
http://www.ap.smu.ca/~pbennett/climate/piomas_icevolquadfit_...

Phil