I get a kick out of all of this. I know some people think this is key to something. I don’t. I think a melted Arctic cap would be good for humanity. I also don’t think it’s going to happen anytime soon.
There’s an interesting article in the Guardian about the ice melting. Well, marginally interesting. It had its share of alarmism, but it was about a study recently done published in the Environmental Research Letters.
In my view, it’s a funny study. The abstract…….
The observed dramatic decrease in September sea ice extent (SIE) has been widely discussed in the scientific literature. Though there is qualitative agreement between observations and ensemble members of the Third Coupled Model Intercomparison Project (CMIP3), it is concerning that the observed trend (1979–2010) is not captured by any ensemble member. The potential sources of this discrepancy include: observational uncertainty, physical model limitations and vigorous natural climate variability. The latter has received less attention and is difficult to assess using the relatively short observational sea ice records. In this study multi-centennial pre-industrial control simulations with five CMIP3 climate models are used to investigate the role that the Arctic oscillation (AO), the Atlantic multi-decadal oscillation (AMO) and the Atlantic meridional overturning circulation (AMOC) play in decadal sea ice variability. Further, we use the models to determine the impact that these sources of variability have had on SIE over both the era of satellite observation (1979–2010) and an extended observational record (1953–2010). There is little evidence of a relationship between the AO and SIE in the models. However, we find that both the AMO and AMOC indices are significantly correlated with SIE in all the models considered. Using sensitivity statistics derived from the models, assuming a linear relationship, we attribute 0.5–3.1%/decade of the 10.1%/decade decline in September SIE (1979–2010) to AMO driven variability.
The Guardian article did the obligatory posting of the arctic ice extent……
Notice how it’s exactly the same as it was 5 years ago. But, before we move on from the study, we should note what’s missing.
The freaking PDO YOU NUMBNUTS!!! Here’s one of their graphs they offered.
The study also states there’s no significant correlation between the AO and the September Ice Extent.
The correlation between the observed AO index (Allan and Ansell 2006) and detrended September SIE is −0.09 which is not significant at the 90% level (see table 1).
You’ll have to click on the link provided to see table one. Now, I don’t believe for a second anyone really has a handle on ice volume, but it may give us some insights as to the general direction the ice going. Look at the blue in in the graph above and then look at this……
Let’s see, according to the blue line (AO) prior to 1981 we saw it going negative. Looking at the graph directly above we see the ice going negative in that same time period, we see the same thing. From about 1981 to about 1985 or a bit beyond we see an increase…. in both graphs. Then we see a decline. No, there’s no correlation……… 
Now, correlation doesn’t equal causation, but only suggests a relationship. Given the recent events with the PDO shift and the ice in the Bering Strait, I’m wondering the value of such a paper or new article worrying about a melt?
One day Western Civilization may go back to actual science. But, I think that’s about as likely as journalism being impartial.
No single model captures the ice variability so they use the models to find ow the ice conditions are related to certain factors.
The models do not work!
The only thing they found is the model limitations, they are no f’n good, and the Vigorous Natural Variability.
james,
There may well be causation with this correlation. that is not the issue. Every scientist accepts that natural variation is inherent in regional and even somewhat global changes. The issue is whether the correlation can account for the spectacular ice loss of the last 20 years.
We seem to be heading toward an ice extent at least close to the record minimum. This in spite of the extremely high maximum ice extent this spring.
the NW passage is open the beginning of August. This will be the 4th(?)year in the past 5 when it has been open. Do you believe that this is a common cyclical occurrence? If it was, someone would have taken advantage of it over the past 400 years or at the very least mentioned it.
Well, there’s plenty of evidence the arctic has in the past been ice free. And, there’s plenty examples of cyclical climate events which occur at periods longer than our exploration of the Arctic. And, as we all know, considering the ships and instrumentation of the past to the ones present, “open” has two different meanings.
But, staying within the confines of the last twenty years, we haven’t seen a decline in ice extent in the last 5. (Note the graphic above is someone’s version of ice volume not extent )
So it may be that we’re even using incorrect grammar here, maybe we should be discussing the Arctic decline as past tense as oppose to present.