This post is in fairness to the sea ice doom mongers. Some have written that sea ice is the Achilles heel of the non-alarmist. The implication is that the melting is unequivocal and absolutely destructive to the skeptic argument. I’m not an idiot, so why keep posting on sea ice?
Because my opinion is that sea ice isn’t melting from global atmospheric warming – at least not in a major way. My Mrs. Cleo impersonation, which is no better than Klimatologists, is that we will see a little sea ice egg-on-the-face data in the next 5 years. Still, the data is the data, and I did promise to perform the same cutoff for the Antarctic as I had done for the Arctic and provide some kind of global single year ice trend.
Unfortunately, the Antarctic has a strong circumpolar current which catches sea ice in a strange pattern that is not suited to latitudinal cutoffs. Big deal, I knew about this result before I said I would do it.
The result is explained below. I cut off all data below -65 degrees Latitude South and above 72 degrees Latitude North.
From those plots I excluded all Antarctic sea ice North of -65 latitude, an admittedly pro AGW choice as the vast majority of the ice in the Antarctic vanishes even south of that line.
My calculation for the southern hemisphere single year ice trend is:
Southern hemisphere (Antarctic) Sea ice North of -65 Latitiude doesn’t exhibit a significant positive trend. It is close though and there are some oddities in the data. Every year this sea ice returns to basically zero. The wiggles are hard to spot but this zero value causes an artificially increased variance in the standard anomaly calculation. It also alters the very basic lag-1 value such that “significance” here is not very accurate.
We have eliminated a LOT of the Antarctic sea ice by this calculation. This is the absolute area value for the Antarctic sea ice North of -65
You can see that sea ice really does return to zero North of -65 degrees. More importantly for us is that the average sea ice level for the above plot is 2.89 million Km^2 whereas the total Antarctic is 9 million Kilometers^2. Yet the average minimum Antarctic sea ice is only 1.8 Km^2 so 80% of the annually melting Antarctic ice is being ignored. We need a non-circular mask.
All that means is that this next plot is pretty worthless. It shows the trend in sea ice for the globe comprised of a reasonable, yet imperfect, Arctic mask and a piss-poor Antarctic mask. Still, I promised I would do it.
We have a statistically significant trend in sea ice for underrepresented Antarctic data and Arctic data on a global scale. I suppose that it is now up to me to provide a more interesting version of this post. After all, if SWAG (Super Warming Activists Guild) is happy with an incomplete presentation here, that is probably something we need to rectify.
the Air Vent 
Because my opinion is that sea ice isn’t melting from global atmospheric warming – at least not in a major way. My Mrs. Cleo impersonation, which is no better than Klimatologists, is that we will see a little sea ice egg-on-the-face data in the next 5 years.
I don’t know about the egg on the face, but it’s always possible that the trend slows down or perhaps even reverses. However, I’d love to hear what you think the mechanism would be. Sunspots? AMO?
Personally, I think ocean heat flux is very important in all this (as does Maslowski, the person who runs the biggest risk of ‘egg on the face’, as he has had the biggest balls to put his money where his mouth is, as early as 2006), so if we see some sort of reversal, it ought to be in that element that influences the thinning of ice. Or some large negative feedback that changes weather patterns in such a way that all the thicker ice remains in the Arctic basin.
So in my opinion it’s one of the two, or maybe if they shut down HAARP. 😉
But what do you think?
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I am unsure why sea ice is some sort of “achilles heel” of those who aren’t alarmed. What exactly is “alarming” about changes in sea ice anyway? Why does any trend in sea ice of necessity herald doom? It seems to be that there is a glaring gap in such logic.
Timetochooseagain said
May 1, 2012 at 11:11 pm
I think the alarm derives from an assumption about the change in albedo from lack of summer sea ice and the resulting feedback. I am not aware of how well that feedback has been modeled or studied from historical records..
I’m sure you could make more money did you not devote so much of your time to this. Thanks again for all of your hard work!!!!!
Jeff –
A link to a recently-made film promoting a sob-story about the vanishing of the ice…
http://chasingice.com/
the synopsis brings tears to the eyes:
In the spring of 2005, National Geographic photographer James Balog headed to the Arctic on a tricky assignment: to capture images to help tell the story of the Earth’s changing climate. Even with a scientific upbringing, Balog had been a skeptic about climate change and a cynic about the nature of academic research. But that first trip north opened his eyes to the biggest story in human history and sparked a challenge within him that would put his career and his very well-being at risk.
Chasing Ice is the story of one man’s mission to change the tide of history by gathering undeniable evidence of our changing planet. Within months of that first trip to Iceland, the photographer conceived the boldest expedition of his life: The Extreme Ice Survey. With a band of young adventurers in tow, Balog began deploying revolutionary time-lapse cameras across the brutal Arctic to capture a multi-year record of the world’s changing glaciers.
As the debate polarizes America and the intensity of natural disasters ramps up globally, Balog finds himself at the end of his tether. Battling untested technology in subzero conditions, he comes face to face with his own mortality. It takes years for Balog to see the fruits of his labor. His hauntingly beautiful videos compress years into seconds and capture ancient mountains of ice in motion as they disappear at a breathtaking rate. Chasing Ice depicts a photographer trying to deliver evidence and hope to our carbon-powered planet.
I hope that no polar bears were drowned in the making oif this film.
“After all, if SWAG (Super Warming Activists Guild) is happy with an incomplete presentation here, that is probably something we need to rectify.”
Is it wrong that I laughed?