So, how does this compare with the Arctic sea ice extent during the Medieval Warm Period?

Reply: very good question, but with a lack of satellite data they just do not know for sure. Brett

I expect to get a lot of commentary, especially from Patrick and Andrew on this one!

Categories: Effects of global warming

I should hope so! I guess you know why.

Is there any documented evidence of a direct link between man-made global warming and the artic ice reduction? If this is the "main culprit", then how is this conclusion reached? Has the "global dust" factor been included (see the June 25 2007 press release, http://nsidc.org/news/press/20070623_PainterGRL.html)? The earth is a big place. We are quite proud creatures when we think that we have such a big impact on it. No doubt, we can do a better job of caring for the planet, but there are some things that we cannot stop, nor should we.

By saying that the ice will gone in by 2030 is a shot in the dark. Nobody knows what could happen by that time. What if a massive volcano blows its top? What if solar output drops for some strange reason? What if Norways moose population dies out and less C02 is produced?

What im trying to say is that eventually something will happen to change our climate, it could happen tomorrow, the day after tomorrow

Okay, I'll bite. For argument's sake, we'll take the leap that a record for 28 years of measurement means something on a orb that is billions of years old. One question: Where is the projected mass flooding of Manhattan, New Orleans, the Netherlands, etc., that was to have been associated with "arctic ice cap collapse?" Perhaps the doom and gloom prognostications may have been just a bit overstated. Since, as a skeptic, I am necessarily a Neanderthal, please educate me as to when I should buy my canoe.

Couple points

First, the amount of arctic sea ice lost since 2005 is over a 1,000,000 km2. WOW!
That is an area larger than Texas and California combined. It is also greater than a 25 percent decline. By my math, Arctic summer sea ice could be practically gone within the next 6 to 10 years. There will of course still be ice burgs coming from Greenland and Ellsmere Island.

Second, operators of General Circulation Models have stated that sea ice is an important component in modeling Global Climate. The IPCC has 18 different models and tends to use the average while drawing conclusions. A consensus approach. So, it is rather surprising that the rate that sea ice has declined actually exceeds the most liberal model in the IPCCs database. See attached link.

http://nsidc.org/news/press/20070430_StroeveGRL.html

While skeptics may jump all over this as some type of proof of something, I do not see it as good news. Not a reason for panic, but for the Northern Hemisphere appears to be changing much sooner than predicted. The southern hemisphere is just the opposite. The ozone hole is cooling things off and changes are happening slower. Overall, things may average out, but more people live in the NH, this is a concern.

Third, Siberia has been shown to be useful for predicting the winter. I suspect arctic sea ice will also influence fall and early winter conditions. However, there needs to be a peer reviewed science article on this subject first.

http://www.nsf.gov/news/news_summ.jsp?cntn_id=109820&org=NSF&from=news

Forth, the northwest passage is now open!

http://www.canada.com/vancouversun/news/story.html?id=8e2ca83d-c6e9-4943-84ca-9cb4597adbdf

The Arctic is likely to be open for shipping within by 2030 according to the experts, but do not be surprised if it happens much sooner.

THE SKY IS FALLING!!!! THE SKY IS FALLING!!!! Better call Al Gore and tell him to tighten the screws on all of the SUV drivers (like himself cough cough) so we can save the polar bears!!! THE SKY IS FALLING!!!!

DENY DENY DENY THE GLOBAL WARMING LIE!!!!

Here is an Inuit expression that has in recent years become increasingly common.

shiku-atok, meaning melting ice...

http://www.haaretz.com/hasen/spages/899567.html

Arna Langa, a 39-year-old Inuit fisherman, still remembers the last time the sea around his village froze over, some 10 years ago. Global warming is changing all aspects of life in Langa's village and all over his homeland.

In the past, we would ride the dogsled westward for miles across the frozen sea to fish for halibut through the snow, Langa recalled. Five years ago, we started seeing cod again - fish that prefer relatively warm water. The soil under the houses has defrosted. Flowers bloom earlier in the year and the sea has lots more little chunks of ice than before.

Like it or not, change is coming.

The strange thing about this report is the immediate actions of all governments involved in talks about reducing greenhouse gasses. Instead of immediate action to reduce the use of fossil fuel we have already witnessed an oil rush as nations peg out the claims of ownership over new potential fossil fuel resources. The same fight is happening at the other pole and duplicate hopes are held for oil deposits under the Great Barrier Reef once it too falls victim to global warming and has its world heritage status removed.
Deniers economic fears are truely unfounded when it is obvious that the main concern is searching for a new source of global warming fuel not the implied effort to control its use.

Interesting that the 30 year record minimum in the Arctic is big news, but the 30 year Antarctic record maximum (which will almost certainly occur in the next three days) in the is not even mentioned.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.south.jpg
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.south.jpg

It shows the ridiculous pro-AGW bias and spoon fed fear of the community and media.

By next summer Arctic ice will probably be back to 2000 levels. This past winter was an anomaly with El Nino and high SSTs, so the ice never got very thick. Freezing has already started about a month earlier than last year.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg

I'm also looking forward to hearing more about Siberian soot and it's impact on melt during the coming year.

Reply: Indeed the current pattern with a + arctic Occillation index is supportive of a colder than normal start to fall and perhaps winter up there. Brett

@Patrick Henry

Patrick,

What is the basis of your belief that "by next summer Arctic ice may be back to 2000 levels."

I have serious doubts myself. Anyway, within 1 years time, your hypothesis will be tested. If this record minimum leads to a very warm winter, the arctic ice may continue to collapse. (Which is whatI think will happen.)

the amount of arctic sea ice lost since 2005 is over a 1,000,000 km2. WOW!

Andrew,

Check this out. Antarctic ice has increased by about 1,000,000 km2 in just the last 10 days! That is 100 times faster than the loss you quoted for the arctic.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.south.jpg

We must be headed into new ice age.

Andrew,

Does Arna Langa remember the ice conditions during the 1930's and 40's? Of course he doesn't. Don't throw these anecdotes from locals into the mix as these people haven't lived long enough to separate the signal from the noise.

To Darren M:

I would hate for the Norwegian moose population to die out; that would give us one less thing to joke about.

Seriously though--if a major volcanic eruption occurred (on the scale of the Mount Pinatubo blast back in the 1990s, then things would be back to normal in a couple of years. This was shown by a paper referenced by Patrick a couple days ago. It would likely take several large eruptions within a very short period of time (a couple years) to significantly disrupt the long-term climate.

In order for a single eruption to create serious long-term consequences, it wold have to be on a much larger scale--think Krakatoa, or for something closer to home: Yellowstone in Wyoming or the Mammoth Lakes Caldera out in California. All are still active and could potentially erupt any time (though we'd have some bit of warning). On the other hand, if one of the two U.S. super volcanoes erupted, we'd have much more immediate problems than global warming--think Pompeii on a continental scale.

To Bill C:

Yes, wind-blown dust can cause snow to melt faster than it would normally. This is similar to Patrick's argument about soot being the cause of Arctic sea ice melt north of Siberia. But it is also important to distinguish what happens naturally from what is caused by human activity. The article you referenced, for instance, states:

Prior to the widespread disturbance of the western United States in the late 1800s and its likely enhancement of dust emission to the mountains, the cleaner snow cover would have lasted several weeks longer, the study said.

I have no doubts that humankind can alter the earth on a significant scale. The Dust Bowl of the 1930s was partly a product of naturally hot and dry conditions across the Great Plains, but one of the most important factors that made it such a devastating period of history for American farmers was the techniques used to till the soil. Farming methods of the day made it easy for the winds to pick up the dry, loose soil and carry it for hundreds of miles in dense clouds. New methods and ideas were later introduced which have prevented similar events from occurring since then.

Considering what such a small group of humans helped create then, it seems overly humble of us to assume that humanity as a whole couldn't possibly affect the earth on a global scale--maybe not through one isolated cause, but through the cumulative effects of everyday human activity.

If Patrick is right and the exceptional melting of Arctic ice this year is due to drilling activity and then illegal burning of Siberian forests, then the final result is still the effect of human-induced changes. If that is the case, then we are fortunate that the solution is so easy.

Indeed, the Arctic needs to be closely monitored over the next five years or so. If anything, it should show deniers how sensitive our climate is and how feedbacks can completely unravel a system.

So,

Does anyone find it strange that these same few guys review all the Global warming articles? Oh and they say the same crap to refute the (obvious facts). I would be willing to bet that at least a couple of you so called readers work for some lobbying shop.

We just want honest facts. These same groups have told us that smoking wasn't bad for you, lead paint was harmless, and that intelligent design (little 'i' for idiots)was real science.

I would say that I know how these tactics work, my roommate works for an alcoholic beverage lobbying group and his only job is to surf the web looking for opposing points about alcohol and refute them with arguments out of a large set of canned response manuals.

With billions of dollars at stake people will say anything to keep the dough, they will even let their fellow man perish doing so.

I tend to trust the people working for 'essentially nothing' but the public good (academia) not corporate think tanks. Quit ignoring the obvious signs that we have messed our world up just for the money, you never know who's house I WILL TAKE IF I LOOSE MINE TO A FLOOD.

Brett,

This paragraph from the Washington Times and swiped from Patrick's post on another thread seems to answer, at least in part, my question in the first post.

Nov. 2, 1922 edition of The Washington Post: "Arctic Ocean Getting Warm; Seals Vanish and Icebergs Melt." .... "great masses of ice have now been replaced by moraines of earth and stones," and "at many points well-known glaciers have entirely disappeared."

Correction:

My previous post does not partially answer my question. Apparently I was off by a thousand years. I should read my own posts once in a while.

Since I've switched from the MWP to the 1920's and 30's, here is a paper that documents a minimal sea ice extent in the 1920's similar to what we are seeing today.

Divine, D.V. and Dick, C. 2006. Historical variability of sea ice edge position in the Nordic Seas. Journal of Geophysical Research 111: 10.1029/2004JC002851

From the abstract: "Historical ice observations in the Nordic Seas from April through August are used to construct time series of ice edge position anomalies spanning the period 1750–2002. While analysis showed that interannual variability remained almost constant throughout this period, evidence was found of oscillations in ice cover with periods of about 60 to 80 years and 20 to 30 years, superimposed on a continuous negative trend. The lower frequency oscillations are more prominent in the Greenland Sea, while higher frequency oscillations are dominant in the Barents. The analysis suggests that the recent well-documented retreat of ice cover can partly be attributed to a manifestation of the positive phase of the 60–80 year variability, associated with the warming of the subpolar North Atlantic and the Arctic. The continuous retreat of ice edge position observed since the second half of the 19th century may be a recovery after significant cooling in the study area that occurred as early as the second half of the 18th century.

The authors also say, "...a similar shrinkage of ice cover was observed in the 1920s-1930s, during the previous warm phase of the low frequency oscillation, when any anthropogenic influence is believed to have still been negligible."

They also say, "...that during decades to come … the retreat of ice cover may change to an expansion."

Andrew, what say ye?

Buzz, Darren M:

The Arctic ice floats on top of the sea. When floating ice melts it does not displace water or add to its volume.

However where the sea Ice connects to land , glacial ice is held back and remains above sea level supported by the land beneath it and blocked by sea ice at the coast for most of the year.

As Patrick will point out the ice on land is not melting that much. However once the sea ice melts glacier ice will be free to slip down hill into the sea all year round.
Propeled by nothing more than gravity, glacial ice will instantly rise sea level even before it melts, which will cause the type of flooding you mentioned.

This is the first stage in an event we will witness in a life time that should take many thousands of years to complete.

An abrupt loss of glacial ice from the Arctic Circle will lighten the surface load currently supported by land. Signalling a weight shift of millions of tonnes from land to sea in such a short time will have an enormous seismic effect as the land bounces back releasing its pent up energy in the type of volcanic activity that concerns Darren M.

The additional weight of water pouring into the arctic waters may also trigger tsunamis as weight squeezes out the magma from the oceanic crust This will heat sea water to new record temperatures which may well displace and gassify methane hydrates trapped 100metres below the Arctic sea.

A combination of a methane gas and lava flows in close proximity would make a great disaster movie and the detonation of such enormous power will turbo charge global warming for both hemispheres.

Darren, to make these things possible the climate must have already changed.

btw does anyone have any ideas about vernshot, and the origins of craters on the moon?

Since I can't sleep, I might as well do some research. In response to my first post on this thread regarding sea ice extent and the Medieval Warm Period (MWP); I have found these:

Keigwin, Lloyd D., The Little Ice Age and Medieval Warm Period in the Sargasso Sea, Science 29 November 1996: Vol. 274. no. 5292, pp. 1503 - 1508

The abstract: Sea surface temperature (SST), salinity, and flux of terrigenous material oscillated on millennial time scales in the Pleistocene North Atlantic, but there are few records of Holocene variability. Because of high rates of sediment accumulation, Holocene oscillations are well documented in the northern Sargasso Sea. Results from a radiocarbon-dated box core show that SST was 1 deg C cooler than today 400 years ago (the Little Ice Age) and 1700 years ago, and 1 deg C warmer than today 1000 years ago (the Medieval Warm Period). Thus, at least some of the warming since the Little Ice Age appears to be part of a natural oscillation.

Hmmm... 1 deg C warmer than today in the MWP. Now that wouldn't have any effect on the Arctic Sea Ice extent, would it?

And this: Grumet, N.S., Wake, C.P., Mayewski, P.A., Zielinski, G.A., Whitlow, S.L., Koerner, R.M., Fisher, D.A. and Woollett, J.M. 2001. Variability of sea-ice extent in Baffin Bay over the last millennium. Climatic Change 49: 129-145.

The abstract: Comparison of an ice core glaciochemical time-series developed from the Penny Ice Cap (PIC), Baffin Island and monthly sea-ice extent reveals a statistically significant inverse relationship between changes in Baffin Bay spring sea-ice extent and Penny Ice Cap sea-salt concentrations for the period 1901–1990 AD. Empirical orthogonal function analysis demonstrates the joint behavior between changes in PIC sea-salt concentrations, sea-ice extent, and changes in North Atlantic atmospheric circulation. Our results suggest that sea-salt concentrations in snow preserved on the PIC reflect local to regional springtime sea-ice coverage. The PIC sea-salt record/sea-ice relationship is further supported by decadal and century scale comparison with other paleoclimate records of eastern Arctic climate change over the last 700 years. Our sea-salt record suggests that, while the turn of the century was characterized by generally milder sea-ice conditions in Baffin Bay, the last few decades of sea-ice extent lie within Little Ice Age variability and correspond to instrumental records of lower temperatures in the Eastern Canadian Arctic over the past three decades.

They found that enhanced sea ice conditions prevailed during the Little Ice Age as opposed to the reduced sea ice extent found during the MWP. They also found that the sea ice extent of the last 100 years was within the variability of the sea ice extent of the Little Ice Age.

This is not a peer reviewed article. So, consider it with caution.

It includes a statement that the Arctic has not been ice free for over a million years.

http://www.livescience.com/environment/050823_ice_free.html

If that is true, then what will be happening in the near future is completely without precedent.

There have been 20 or so interglacial warm periods in the last million years. Some have been warmer than the current climate, but if none resulted in an ice free arctic ocean, then things may become very strange.

At the minimum, the climate of the 80s and 90s is history. All the long term forecasting models will have to be re-written.