Continued from here .
On August 19, 2009, NSIDC published the following August forecast of sea ice minimums by the leading climate modelers around the world. The majority of modelers predicted that 2009 sea ice minimums would be below 2008 and one (Arbetter et al) even predicted that 2009 would break the 2007 record. The range was 4.2 to 5.0 million sq km. Detailed report is here.
While I don’t usually get involved in guessing outcomes of various climate situations (where no one has any real basis for their guess), I do occasionally. I called a low 2006 hurricane season very early. And on August 7, two weeks before the publication of the modelers’ forecasts, I observed:
2009 is now slightly behind 2008. My prediction is that 2009 will end up over 500,000 sq km behind 2008.
That prediction didn’t look all that great a couple of weeks later, but right now it looks pretty much right on the money. As of today, 2009 is 470,000 sq km behind 2008 and the chances of 500,000 seem pretty realistic.
That my guess was so close was due more to good luck than acumen, but there were some reasons for it. Canada has some exposure to northern weather and it has been a cool summer here and very cool in northern Ontario. 2008 had not been as big a melt as 2007 and presumably there was presumably a bit more two-year ice in 2009 than in 2008. While 2008 and 2009 were about even at the time, the trajectories looked different and it seemed to me that 2009 might stabilize at a higher level than 2008.
And yet in early/mid August, these factors didn’t seem to be on the minds of the official agencies since, as noted above, EVERY official agency substantially over-estimated the melt.