What do you think of this year's Arctic sea ice melt?
According to the National Snow and Ice Data Center (NSIDC), Arctic sea ice cover appears to have reached its minimum extent for the year, the second-lowest extent recorded since the dawn of the satellite era.
While above the record minimum Arctic sea ice extent set on September 16, 2007, this year further reinforces the strong negative trend in summertime ice extent observed over the past thirty years.
Even though the sea ice didn’t retreat this year as much as last summer, “there was no real sign of recovery,” said Walt Meier of NSIDC. This year was cooler and other weather conditions weren’t as bad, he said.
“We’re kind of in a new state of the Arctic basically, and it’s not a good one,” Meier said. “We’re definitely sliding towards a point where the summer sea ice will be gone.”
Scientists have predicted that the Arctic will become ice free in the summer by the year 2013, if not sooner.
So it didn't quite break last year's record, nor did the north pole become ice free as a few scientists predicted it might. However, the melt was the second greatest in recorded history, and the long-term trend continues clearly downward.
I think maybe of more interest than the total ice melt is that its timing was different this year, with there being much more ice lost in later in the summer than observed in the past. Coupled with the fact that most estimates claim that only about 1/3 of the observed warming in the arctic can be attributed to the direct radiative forcing from anthropogenic greenhouse gases (although I have heard it argued that short-lived anthropogenic species might be responsible for warming not due to GHGs), it suggests there are some fairly radical changes in climate going on in the arctic.
What people probably should be taking away from this is not so much the total ice loss (or recovery for that matter) each season, but the change in dynamics. For those who are clued in scientifically and understand why "climate change" is a more appropriate term than "global warming" for what is happening, the change in arctic climate provides a great example of what are termed "nonlinearities" in the system. Of course, if you are of the mindset that believes "climate change" was chosen for purely political reasons, then anything that deviates from a one-to-one correlation between rising CO2 levels and uniform temperature increase over the planet only indicates that the whole theory is wrong.
The first reference gives the 1979 to 2000 average as a comparison to 2007 and 2008. I think that the graph would be more informative if all of the curves were plotted, or at least the standard deviations on the average. The second source implies that the SD is about 1/4 of the signal, but these are annual averages so the numbers cannot be directly compared without accounting for seasonal effects. The June ice extent may be within the SD for the average, but it would appear that the September ice extent in recent years is significantly outside a SD for the average. A better, but perhaps more difficult measurement would be the ice volume rather than area.
The increasing arctic ice melt indicates more energy is arriving in the arctic. I think that the relative contributions of a change in albedo and energy flux from lower lattitudes (via ocean currents) to the excess energy is an open question.
Its up 13% on last year and at the end of summer, thats an area the size of germany recovered. According to shipping reports the ice is not navigatable without an ice breaker, which suggest the satelite is not correctly reading the new thin ice mass (this is a known issue with the satelites, compare NASA and UIUC and there are discrepancies). Satellite images show its nowhere near being an island and if you look over previous images it has had a similar ice mass as today 20 odd years ago (though again, the statelites often fail to pickup the thinner new ice so a accurate comparison is not really possible between any year).
Its not the second lowest in recorded history, in geological terms ice at the poles is a rarity only having occured for around 10% of history. In more recent times the poles were navigatable during the 1920's and 1930's, this is well documented.
This is proof nothing other than a natural cycle and it is caused by a warm current passing through the area, not warming of the atmosphere. Air temperature does not melt the ice at the north pole (average temp -26), the sea does and the sea has a temperature memory of thousands of years.
Also according to climate scientists warming should increase ice mass due to increased precipitation and cloud cover which cools the poles further, as has been observed in the southpole.
Its a classic case of scare mongering, nothing more, can we please hear about the growing ice mass of the antarctic instead?
Not surprising. Like what the proponents were going on about earlier this year, new ice is thinner, making for an easier melt. I haven't really seen a temperature record for the Arctic, and how La Nina effects us down here really means nothing in the Arctic. Meier said warm ocean waters made a large contribution to this melt, so obviously it was warmer up there.
What I think is: We are still learning about the planet we live on. The first sentence you copied and pasted to your question says a lot in just a few small words at the end of it: "since the dawn of the satellite era".
I also feel since it appears air temperature doesn't have as much effect on the Arctic as otherwise thought (This learned due to the fact it was colder up there this year than it was in recent years.) So we know other things are at play here, like the Pacific and Atlant ocean. Since it melted more on the Atlantic side this year then it did on the Pacific I'd say the Atlantic ocean was warmer this year than the Pacific ocean.
So even though the Arctic didn't rebound as much as I was hoping it would this year, I'm not as pessimistic about it as the person who wrote the blog you quoted.
With the Pacific ocean cooling off I expect we will see more rebounding of the ice on a yearly basis. Also since these PDO patterns can last along time, any where from 30 to 70 years, we could be in for a major cool down that could last not only the rest of my lifetime, but the rest of yours as well.
Now I'm watching how quickly the ice reforms this year, since the faster it does the thicker it will get this winter, so I'm watching for the true minimum.