« on: April 21, 2017, 10:09:25 AM »
In the absence of geoengineering activities, when do you think the Arctic will experience its LAST year with a Sept minimum sea ice extent ABOVE 1 million square km?Unless my english is really off the wording specifies LAST time ABOVE. That is NOT the same as the FIRST time ABOVE. That means to me all you need as one cold summer and you can have ice hanging around all summer. Maybe not much above 1M km2 but still above.
This is looking at human lifetime scales, not century or epoch scales so no, it won't be the absolute last unless the sun explodes. Just global warming impacts, not nuclear winter etc.
Therefore based on that interpretation I do see a chance of having a cold enough summer to have ice lasting all summer long.
As for the exponential vs Gompertz argument. Gompertz has a big problem because it only works if the melt is only as a result of sun influence. The real results are that as the thins the it becomes much easier for the wind and waves attack and move around the thick ice. That means it will then get broken up and moved out of the Arctic. Bye bye Gompertz chart. As for exponential. It all depends on how steep you make that curve. To get below 1M you need not only high enough temperatures, but favourable wind and wave action for that first ice free summer. We are close enough to 2020 with still enough ice that we still may see ice after 2020, but based on condition of the ice right now, all it will take is a 2007 or 2012 summer and it will be all gone.