The wager

Willis Eschenbach has made a bet with me regarding ice extent. The proposition is that daily ice extent will fall below one million square kilometres by the end of the 2014 melt season. Willis has the negative; I have the affirmative. The bet is for $US100.

We will use the http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm as our adjudicator, with the final values on 1 November 2014. Obviously, I can win the bet well before then - if sea ice drops below that value on 14 September this year, for example. If Willis wins, he will have to wait for his money until November 2014.


These are the relevant posts from WUWT:


Willis Eschenbach says:


June 1, 2010 at 2:53 am

David Gould says:

June 1, 2010 at 2:15 am

Nigel Harris,

I agree. It is exactly the pattern that we would expect to see. 2007 changed things. It was, indeed, a tipping point (and I know how much that term is loved here. :)). I am one of those alarmists who think that the Arctic will effectively be ice free at the end of the melt period very soon. My specific guess is 2014.

Care to put some money on that prediction? I’m a betting man … a hundred bucks says it won’t go below a million square km of ice by 2014?

And why is it “the pattern that we would expect to see”? Do you know of anyone who predicted it before 2007, anyone who foresaw that we would see a) increasing ice area, combined with b) greatly increased winter ice, and c) greatly reduced summer ice? This is historical revisionism.

Me, I think this new pattern reflects a change in satellites, or a change in procedures, or something like that. But hey, I’ve been wrong before …



1. David Gould says:

June 1, 2010 at 3:09 am

Willis Eschenbach,

No, I know of no specific prediction of this. However, ice cover is a two-dimensional model. Thus, if we have strong melting in the melt period, we would still expect the ice to recover on the surface during winter, and to roughly the same extent as usual – in other words, we would see a strong up and down signal, with more variance between the top and the bottom.

You are correct that there would be no expectation for a higher rebound in winter. That is more likely to be noise over the last couple of years.

As to a bet, $100 sounds fine. I am assuming that you are talking in US dollars.

And which dataset do you want to use? They are all somewhat different in the values that they give, as they all have slightly different procedures. These guys http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm are fine with me. We should wait for corrections, though. I am not sure how long they take, but perhaps the data as presented on that site on 1 November 2014, my time (Australian time)?