Arctic sea ice decline happened faster than expected. This has the effect of accelerating global warming because less of the Sun's energy is reflected back into space by ice.
Northern Hemisphere snow also sends some of that energy back into space. The amount of snow cover we have is also declining.
Difference from average annual snow extent since 1971, compared to the 1966-2010 average (dashed line). Snow extents have largely been below-average since the late1980s. Graph adapted from Figure 1.1 (h) in the 2012 BAMS State of the Climate report.
The warming of the Arctic region is also probably causing an increase in the amount of CO2 and Methane, previously frozen in permafrost or offshore, that is going into the atmosphere. For this and other reasons, Methane, along with other greenhouse gases, are increasing. I quickly add that stories you've heard of a civilization "methane bomb" in the Arctic are not supported by the best available science. But these additional greenhouse gases still count.
![Global average abundances of the major, well-mixed, long-lived greenhouse gases - carbon dioxide, methane, nitrous oxide, CFC-12 and CFC-11 - from the NOAA global air sampling network are plotted since the beginning of 1979. These gases account for about 96% of the direct radiative forcing by long-lived greenhouse gases since 1750. The remaining 4% is contributed by an assortment of 15 minor halogenated gases including HCFC-22 and HFC-134a (see text). Methane data before 1983 are annual averages from D. Etheridge [Etheridge et al., 1998], adjusted to the NOAA calibration scale [Dlugokencky et al., 2005].](/files/gregladen/files/2015/01/aggi.fig2_.png)
Global average abundances of the major, well-mixed, long-lived greenhouse gases - carbon dioxide, methane, nitrous oxide, CFC-12 and CFC-11 - from the NOAA global air sampling network are plotted since the beginning of 1979. These gases account for about 96% of the direct radiative forcing by long-lived greenhouse gases since 1750. The remaining 4% is contributed by an assortment of 15 minor halogenated gases including HCFC-22 and HFC-134a (see text). Methane data before 1983 are annual averages from D. Etheridge [Etheridge et al., 1998], adjusted to the NOAA calibration scale [Dlugokencky et al., 2005].
Now we are learning that glacial ice, in particular in Antarctica, is melting faster than expected.
That video is from a recent post by Peter Sinclair, who has more on glacial melting.
We knew a lot of the additional heat (from global warming) was going into the oceans, but now we have learned that a LOT of this heat is going into the ocean. This heat goes in and out, so what has been going in will likely be going out (into the atmosphere).
90% of the Earth's energy balance involves the ocean's heat, shown here. Note that there is no current pause, and that surface temperature estimates (see graph above) tend to underestimate the total amount of anthropogenic global warming because much of this heat, routinely, goes into the ocean. We can expect some of this heat to return to the atmosphere in coming years.
(See also this post by Joe Romm.)
This causes me to look at a graph like this ...
Figure SPM.5. Solid lines are multi-model global averages of surface warming (relative to 1980–1999) for the scenarios A2, A1B and B1, shown as continuations of the 20th century simulations. Shading denotes the ±1 standard deviation range of individual model annual averages. The orange line is for the experiment where concentrations were held constant at year 2000 values. The grey bars at right indicate the best estimate (solid line within each bar) and the likely range assessed for the six SRES marker scenarios. The assessment of the best estimate and likely ranges in the grey bars includes the AOGCMs in the left part of the figure, as well as results from a hierarchy of independent models and observational constraints. {Figures 10.4 and 10.29}
... and figure that warming over coming decades will be at, near, or even above, the range previously estimated.
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More like this
Looks like it is time once again to adjust the ocean heat content scale upward again. Or we can just watch Senator Jim Inhofe again, and not worry about it.
I think the Congressional Oversight committee has required that NOAA/NASA can not have a vertical scale greater than +20 * 10^22 on Ocean Heat Content graphs.
Heh! Like North Carolina. Any day now Congress will outlaw the metric system because it causes air craft to not fly.
Why shouldn't Congress outlaw those like Jim Inhofe because they cause Americans not to think? Wait... That IS what they want to happen, isn't it?
Why shouldn’t Congress outlaw those like Jim Inhofe because they cause Americans not to think?
The USA Republican Party already has an entire cable network working to make sure Americans don't think.
This is precisely the place where we don't want the ocean warming up. There's a lot of methane up there. There have been studies. Some say methane is/will be a huge problem. Others say not to worry. I think the scientists telling us not to worry are using the best data they can find to limit the impact of the methane problem. But then I've read some pretty nasty reports on the methane problem. I think the scientists refuting those reports are trying to keep mass hysteria from breaking out.
What would a scientist do if he had information that a major methane event was eminent off the West Coast of America? Who knows what the effects are of such an event? Should they evacuate? Should no one light a match? Will there be a mass asphyxiation? There is evidence that vast amounts of methane have begun to seep out of arctic regions, under the sea and in the tundra. Once that process starts, it doesn't stop. And once it starts, it accelerates global warming. It's times like this that I really, really want to believe the scientist that tell me not to worry about the methane.
My response to this is a string of expletives.
Not because I don't accept the science and reality here but because its is so much worse than we thought and happening much faster and, yes, I am scared about what this means for us all in the future. Make that present.
does not the albedo effect referenced in regards to the arctic also apply to the Antarctic?... especially because the extent of the ice extends further from the pole, resulting in more direct sunlight being reflected.
The albedo effect works on both ends of the planet, but has very different levels of significant since the vast majority of the "landscape" in the Antarctic is continent covered with ice. So the variation due to sea ice is very small there.
Thank you for another great article Greg. This is one worth sharing.
greg, thankyou for your response. I think I must have asked my question incorrectly. I believe that the expanding Antarctic ice has a more substantial albedo effect because of the solar angle.
I had been doing some star gazing years ago and found an article on increased albedo of solar system bodies. That was around ten years ago but I don't know how old the article was.
The Soviets had at one time experimented with warming up areas in Siberia by spreading soot from power plants to melt ice and permafrost.
They also tried deploying huge Mylar mirrors to reflect sunlight to lengthen growing seasons.
There's a neat video of the mirror coming apart under centrifugal force. Could be the spars couldn't handle the torque.
Anyway it was a grand effort.
A recent study of glaciers on an island up north told of layers where soot and ash from wild fires had been deposited, the ash coming from forest fires thousands of miles away.
Don't remember the name of the island, but part of what they were studying was the effect of increases in geothermal activity under the ice at some locations.
I figure that with the present world situation the coming nuclear winter will off set the effects of Global Warming.
Then we can emerge from our shelters and start building flying cars and robot maids once again.
Either that or become wandering bands of hunter gatherers and start over from scratch.
@tony watson
Tamino did some detailed analysis
https://tamino.wordpress.com/2012/10/01/sea-ice-insolation/
"... the global climate forcing from Arctic sea ice changes would be about +0.13 W/m^2."
"... the global climate forcing from Antarctic sea ice changes would be about -0.02 W/m^2."
Perhaps some contingency plans are in order.
There is an island in the Pacific that's partly artificial. Ages ago the people who lived there wanted more room so somehow they transported basalt columns there and used these to increase the surface area and strengthen the shoreline.
If people who had not invented the wheel could do that I figure we could figure something out to protect coastal cities.
The Dutch built an entire country using stone wood and wind power.
Have there ever been any realistic studies on just how our civilization would adapt to the worst case scenario of climate change?
Its not that I don't believe that something could be done, that's always a possibility, it just that I don't believe anything actually will be done.
Too much effort has gone into selling the idea, and too little effort has gone into providing workable answers.
Once politics became a factor things went off the rails.
tony, good question. The sun shines on the entire pole for a oeriod if time so i'm not sure about that. The fact that we've seen more amplification of heat in the Arctic sugests the Arctuc is still more affected. Also the Antarctic remains as a cold, shiny core while the Arctic is a warming sea.
MikeH, thanks.
GY you should look into the Dark Snow project.
"
Greg Laden
January 24, 2015
MikeH, thanks.
GY you should look into the Dark Snow project"
Thanks that something I can sink my teeth into.
This
"Scientists estimate that if all of Greenland's ice sheet were to melt, the global sea level would rise by 23 feet (7 meters)."
Sounds a bit exaggerated.
Granted the ice sheet is very thick, but the surface area is tiny compared to the surface area of the worlds oceans.
I don't know how reliable this site is
http://www.aip.org/history/climate/RainMake.htm#N_7_
But it has some information and references for the Russian projects
"A more feasible scheme would be to spread particles in the atmosphere, or perhaps directly on the ground. Beginning around 1961, Budyko and other scientists speculated about how humanity might alter the global climate by strewing dark dust or soot across the Arctic snow and ice. The soot would lower the albedo (reflection of sunlight), and the air would get warmer.(7) Spreading so much dust year after year would be prohibitively expensive. But according to a well-known theory, warmer air should melt some snow and sea-ice and thus expose the dark underlying soil and ocean water, which would absorb sunlight and bring on more warming. So once dust destroyed the reflective cover, it might not re-form. "
"Sounds a bit exaggerated."
No, it is not an exaggeration. This is not that hard to measure. See this for more information: http://gregladen.com/blog/2015/01/how-high-can-sea-level-rise-if-all-gl…
The part of New Jersey I've had to spend time in caring for my family (near Princeton) is part of what used to be a sea, with the Sourland mountains being the end of the mid-Atlantic rift valley (not the African one). Sea levels were 200+ feet higher. Also look up the Laurentide flood.
http://honeybeesandhelium.com/tag/laurentide-ice-sheet/
The amount of ice in Antarctica and Greenland is staggering, and although with the weight removed the land will rise, once it all begins to melt it will all go.
The idea that time will stop somewhere around 2100 is just silly. People born today may be alive then, though if we continue to neglect events and infrastructure, perhaps we won't be able to live so long.
In Cornwall near Land's End, the "raised beach" is visible at about 22 feet above sea level.
Anybody got the Cliff's notes on why the Arctic should be more sensitive to 'global' anthropogenic climate change?
For now, I'll just go ahead and stick that little factoid into my *metabolic imbalance* (between respiration/photosynthetic -- CO2/O2) column and call it a day also add PCBs to my 'short list' of culprits:
http://oceanservice.noaa.gov/facts/pcbs.html
http://climatestate.com/wp-content/uploads/2013/05/o2-oxygen-decline-co…
And Glyphosate? "AMPA has low toxicity which is comparable to that of glyphosate and it is therefore considered to be of no greater toxicological concern than glyphosate itself." <-- That should reassure any concerned potted plant life.
http://en.wikipedia.org/wiki/Aminomethylphosphonic_acid
-------------------------------------------
http://www.al.com/news/huntsville/index.ssf/2015/01/noaa_says_2014_was_…
**Shirley, he's talking about the heat. Apparently, this guy misunderstood:
http://priuschat.com/threads/it%E2%80%99s-official-2014-was-the-hottest…
http://docs.lib.noaa.gov/rescue/mwr/050/mwr-050-11-0589a.pdf
"Tim
January 24, 2015 "
I remember seeing that one years ago. They must have been frantic.
I remember an article from the 30's where a guy gave a very convincing argument that sharks never attacked humans, that all records of shark attacks were due to misidentification and that Barracuda and Sea Bass had been responsible for all those attacks.
If the sea levels were to rise to any great extent I can just see land speculators looking for property a mile or so inland with terrain that would make it a good harbor or port city in the future when water filled in the valleys and ravines.
These mountains were islands in the distant past, they have dug up fossil sea life at high elevations.
Guess I'll start drawing up plans for a marina.
There was talk in the news maybe ten years ago about Russia trying to secure claims to mineral wealth of arctic sea areas now unreachable due to ice cover.
Maybe some cabal of old die hard commie scientists are sitting about making toasts to the success of that climate modification scheme they started in the 1960's.
"Anybody got the Cliff’s notes on why the Arctic should be more sensitive to ‘global’ anthropogenic climate change?"
Maybe a bit poorly worded, but the arctic is expected to warm more than the global average. It also has a biosphere that is most likely to undergo massive changes upon warming. Some basics here:
http://acia.cicero.uio.no/factsheets/1_arctic_climate_trends.pdf
During the Medieval Warming Period Greenland and Iceland were more affected by warming than most places.
At least thats what records would suggest though other regions did warm up to some extent.
I wonder how much of the Greenland ice cap might have melted during that period and what the effect was on sea levels. There was not much arctic sea ice then either.
GY, how do you know "there was not that much arctic sea ice then either"?
This is what Polyak et al found:
http://www.geo.umass.edu/faculty/jbg/Pubs/Polyak%20etal%20seaice%20QSR1… (see figure 12).
Here is a summary of Kinnard et al that goes back a bit further:
http://www.skepticalscience.com/Arctic-sea-ice-hockey-stick-melt-unprec…
It is the first figure
Ever seen a Knarr?
How far do you think you'd get sailing from Norway to Iceland in a Knarr if there was much sea ice?
Of course there were no satellite photos so we can only go by surviving accounts of the voyagers.
"But the chain of communities connecting mainland Scandinavia with the New World did not long survive. Archaeologists who have examined L’Anse aux Meadows in Newfoundland tell us that this settlement lasted just a few decades, perhaps only a few years. Subjected, after 1300, to increasingly cool summers and greater amounts of sea ice, the Greenland colony, numbering between 3,000 and 5,000 souls, fell on hard times and died out by about 1450."
So sea ice increased towards the end of the warming period and is considered to be a factor in abandoning the Greenland settlements.
http://www.naturalhistorymag.com/htmlsite/master.html?http://www.natura…
http://www.geo.umass.edu/faculty/jbg/Pubs/Polyak%20etal%20seaice%20QSR1…
Maybe you should read that PDF more closely.
They recognize evidence of warming and decreased sea ice around the time of the MWP with open channels. They don't say Medieval Warming Period they just give the dates of 1000 and 500 AD.
If a 400 yr period of retreating sea ice is to be ignored then we might as well ignore the last century of retreating sea ice as well.
At the end of the MWP after Greenland settlements were abandoned when sea ice began to return to earlier levels the Norwegians began combining elements of the design of the slower but more sturdy Cog with their traditional lighter built Knarr.
The Cog and the Hulc were no ice breakers to be sure but they were sturdy with heavy cross bracing and better able to withstand an occasional slow speed impact of drifting sea ice.
In the 1960's sea ice increased around Iceland nearly destroying the economy, even modern steel hulled vessels with powerful engines were at risk.
The decreased sea ice and warming of the artic around Greenland that is in part the basis for this claim that the effects of Global Warming are being felt ahead of predictions suggests that the predictions and models need to be re examined.
Whatever caused the MWP may be at work and since all attention has been directed at greenhouse gases they aren't looking for the true cause.
Perhaps both mechanisms are working their mischief at the same time. Then we might really have something to worry about.
I just want to remind everyone that part of Europe were very warm during the Medieval Climate Anomaly (no properly called the MWP for a couple of decades now though historians probably use that). But this is very different than modern day Arctic amplification, both in terms of the anomaly itself and the global context.
The MWP is not a climate period, it is not an exceptionally warm global period. It is a horse. A dead one. Not worth beating.
There are several papers on the subject, and the last I read is that the MCA was #1 not global and #2 Earth was cooler then than this decade, and the previous decade, and the previous decade. Some papers:
http://muller.lbl.gov/TRessays/23-Medievalglobalwarming.html
http://www.skepticalscience.com/medieval-warm-period-intermediate.htm
http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html
http://www.meteo.psu.edu/~mann/shared/articles/MannetalScience09.pdf
http://www.esrl.noaa.gov/psd/data/gridded/data.noaamergedtemp.html
http://www.grida.no/publications/other/ipcc%5Ftar/?src=/climate/ipcc_ta…
http://www.ncdc.noaa.gov/paleo/pubs/moberg2005/moberg2005.html
http://books.nap.edu/openbook.php?record_id=11676&page=R1
http://www.sciencemag.org/content/326/5957/1256.abstract
http://www.springerlink.com/content/a42l382370422365/
http://www.geosociety.org/positions/position10.htm
http://www.bioone.org/doi/abs/10.1579/0044-7447-29.1.51
http://climateknowledge.org/figures/Rood_Climate_Change_AOSS480_Documen…
"The MWP is not a climate period, it is not an exceptionally warm global period. It is a horse. A dead one. Not worth beating."
I never said it was due to a Global Warming scale event. But its not to be brushed aside either when the un predicted levels of sea ice retreat in the Arctic is at least part of the subject.
The Medieval Warming Period is an historical fact regardless of whether the effect was global.
There have been studies on the historical ranges of plant species in China that suggest that the Warming Period was not confined to Europe.
I'm no historian but I have read and studied the Icelandic Eddas and other sources that deal with this period in Europe when I was younger.
Everything I've read on the subject indicates that there was a much less sea ice during that period than before or after, and that this allowed the settlements in Iceland and Greenland. Iceland didn't go the way of Greenland true enough, but sea ice became more and more of a problem after Greenland was abandoned.
I've also long been interested in sailing and the designs of wooden sailing ships through out history.
The Cog was primitive compared with the merchant vessels of later centuries but it had a sturdy hull with cross beams that extended beyond the hull. It could handle minor impacts with drifting sea ice. The Norwegians seem to have used the Cog and Hulc more in the late 15th and early 16th century when significant drifting sea ice once again became a factor in the Norway sea and much more of a problem the closer they got to Iceland.
These days sea ice hasn't been nearly as much of a problem in the Norwegian sea due to the warm Norwegian current, but Iceland has had on again off again serious problems with sea ice even when sturdy modern vessels with powerful engines are the norm.
I can find any information on the effect of the MWP on the Greenland ice and whether there was a rise of sea levels somewhere else.
There were news stories of ancient fortresses along the coastlines in Scandinavia and in low lying areas inland being uncovered by falling sea levels some years ago. Those predate the MWP and may be related to an earlier period where some Roman era trading cities on the European coastline disappeared under the waves after massive storms that make any we've seen in this century pale by comparison.
Either I'm missing your point or you are missing my point. Let me explain your point back to you and you can tell me if I have it right. You are saying that retreat of sea ice around Greenland and the general vicinity of the North Atlantic during the MCA was similar in extent of recent retreat of sea ice. This, you claim, means that the current retreat of sea ice not anything special, because it happened before, recently.
Is that what you are saying?
Regarding Chinese plants, if you are going to mention a study to make an important point, cite the study. If you can't cite the study it can't be considered, for obvious reasons. In any event, there were a number of places that were warmer during the MCA including areas near china and also north america. It was not confined to Europe.
There was no rise of sea level during the MCA.
GY,
I might speculate that the Gulf Stream, being very dynamic and somewhat chaotic, may have done a little contortionist act and gotten part of itself sort of quasi-stable 'herniated' between Labrador and Greenland back then.
http://marine.coastal.edu/gulfstream/p5.htm
http://www.whoi.edu/main/news-releases?tid=3622&cid=152829
GY, Polyak et al indeed acknowledge some periods with lower ice than average, but not periods that are similarly low compared to today.
"Ever seen a Knarr?"
Yes.
How far do you think you’d get sailing from Norway to Iceland in a Knarr if there was much sea ice?"
That's a rather difficult question to answer, other than by saying that even when there was a lot of sea ice, Iceland would still be largely free from sea icea. There may have been problems with icebergs and other floating ice sheets, but those would primarily be a problem in winter and early spring. Remember that the Vikings travelled mainly from May to September. Autumn and winter travels were very uncommon (and then likely through the insular route via the Faeroe Islands).
There was indeed an expanse of sea ice in the late 1960s, but that was primarily North of Iceland and was short-lived.
But all this is somewhat beside the point of arctic sea ice extent, as it focuses on a rather narrow region. Polyak et al covers the whole arctic.
"The Medieval Warming Period is an historical fact regardless of whether the effect was global."
A big problem in the literature (yes, dear colleagues, you listerning?) is that the MWP or MCA is often time-wise very poorly defined. That is, you can find papers that say MWP! and you find it was from 800-1000 CE, and then another paper that says MWP! with the time period 1100-1300. There's a nice database on CO2science (which I am not going to link to) of papers that report a "MWP". Of course, our friends the Idso's use it to claim there was a global MWP, but if you go through the paper you quickly find out all those MWP's are spread out over many centuries, and you can easily found a cold period in area X of the world matching a warm period in area Y of the world. It's also a pattern seen in ice cores: those in Greenland and Antarctica tend to be opposite in their thermal behavior (excluding around the glacial-interglacial transition).
So it is possible that there have been periods in the distant past where sea ice around some regions of the arctic matched those of today for some period of time. There is, however, no credible evidence - and in fact contrary evidence from scientific studies - that arctic sea ice extent has been as low as today in at least the last 1500 years.
"Is that what you are saying?"
Nope.
China
https://www.google.com/url?q=http://faculty.fgcu.edu/twimberley/EnviroP…
BTW
The Cog was braced with cross beams in much the same way as Roman era ingot/ore carriers of the Gauls.
The Romans wrote that these ships were not vulnerable to damage by ramming because of the cross beams one foot thick.
The Romans adopted this design for merchant ships sailing in the Atlantic. The "Asterix Ship" now under study is the best known example.
Most modern maps of the Norway Sea that I've seen show Iceland pretty much surrounded by sea ice except for the eastern tip.
Greenland seems to have been little troubled by sea ice till aprox 1300 about the time that sea ice became a concern in Iceland. As sea ice increased the Greenland settlements became unsustainable. The cargo ships, even the sturdiest, just stopped coming, it wasn't worth the risk.
Dunwich was inudated by an epic storm and partly destroyed in 1286, another massive storm pretty much completed the job in 1347.
The cities and town in Britain and on the coast of the continent destroyed by storms during and towards at the end of the Roman era are harder to pin down, some sliding into myth.
Earlier the Romans had written of the seas around Albion being unusually calm and easy sailing.
The subject is whether the effects of Global Warming are being felt earlier than predicted.
If more than one factor is at work then why not investigate any possible contributors.
Generally unexpected events are due to a combination of factors.
Look in one direction too long and we might get blind sided.
The greatest storms, the ones that destroyed cities and inundated the countrysides destroying other towns and villages driving inhabitants inland seem to have come towards the end of those warming periods.
When all you have is a hammer every problem looks like a nail.
"Most modern maps of the Norway Sea that I’ve seen show Iceland pretty much surrounded by sea ice except for the eastern tip."
If you mean the Norwegian Sea, I'd love to see those maps, because the Norwegian Sea formally does not include Iceland and the Norwegian Sea is considered ice-free all year round.
Also remember that deep in winter there may be some drift ice floating through the Denmark Strait which means ice may be pushed towards Iceland. There is also ice coming from some of the glaciers. And yet, none of this means there was any problem with sea ice for those poor Vikings in their small boats, since they travelled primarily in spring and summer.
"If you mean the Norwegian Sea, I’d love to see those maps, because the Norwegian Sea formally does not include Iceland and the Norwegian Sea is considered ice-free all year round."
I'll dig up links to a few.
The maps of the Norwegian sea include the eastern tip of Iceland, not the entire island. Maps like this don't stop at the demarcation they show the limits of the sea and surrounding waters. Land for some distance beyond the NS is shown as far as Greenland.
"Also remember that deep in winter there may be some drift ice floating through the Denmark Strait which means ice may be pushed towards Iceland. There is also ice coming from some of the glaciers. And yet, none of this means there was any problem with sea ice for those poor Vikings in their small boats, since they travelled primarily in spring and summer."
They didn't travel to Iceland at all before the 9th century.
The Greek who first saw "Ultima Thule", believed to be one of the Norwegian islands further south, described it in terms that modern mariners recognize as being surrounded by plate ice impassable for sailing ships of that day.
So was the Norwegian sea always free of significant sea ice before the 7th century?
Irish Monks had reached Iceland in the 6th century, and it was warm enough for them to set up a settlement. How much ice did they have to contend with?
In 1695 Iceland was completely locked in ice, the inhabitants were in peril.
That on the edge of the warmer Norwegian Sea.
The main point is the ice around Greenland. That we know became impassable at the end of the Medieval Warming Period.
The Norwegian sea as I said didn't have much sea ice, and neither did the Greenland sea during the MWP.
The Cog was the safer choice when drifting sea ice returned .
Besides its sturdy cross beam braced hull that could better withstand impact with drifting ice, the crew and cargo were better protected from the elements , and the Cog had a primitive but effective bilge pump to handle sea water that reached the hold during storms at sea.
During the MWP passage to Iceland and Greenland, not to mention navigating around the entire island of Iceland as the first Viking explorers had done, was a cake walk compared to later centuries, until more recent times at least.
Here's a rough map without ice
http://www.worldatlas.com/aatlas/infopage/norwegiansea.htm
Note only the very eastern tip of Iceland touches the Norwegian sea.
As listed here
http://en.wikipedia.org/wiki/Norwegian_Sea
The "Basin Countries" are Iceland and Norway.
I'll add a few sea ice maps later.
I love the idea that Greek (or Roman) writers or travelers did actually make it to distant lands and such, but my understanding is that Pytheas is generally not considered a trusted source.
It would not be surprising to see a lot of sea ice in 1695, as that was a relatively cool period in the Northern Hemisphere:
http://www.skepticalscience.com/new-remperature-reconstruction-vindicat…
"my understanding is that Pytheas is generally not considered a trusted source. "
Only because his vocabulary was not up to describing sea ice, which he had never seen before.
There's an old story about an African sent to observe a missionary preaching to his flock.
The African reported to his people that a man wearing a dress held a black bird with speckled wings in his hands and when the wings were spread God talked through the man in the dress.
The African had no words in his vocabulary for Book, pages, printed words, reading , etc.
There have been recalculations that took into account previous errors in calculations and the island was pinpointed.
The odd description has been recognized to mean that the ship could not make land fall due to drifting pancake ice and debris and thick mist or fog.
Similar descriptions of fog making it hard to tell where the sea ended and sky began are found in much later tales of the sea, but are more easily understood.
I'm no scholar, I just had a strong interest in history, and the less that was known for certain the more my curiosity was peaked.
Legends often have a basis in fact, and this is an example.
The Icelandic Sagas are more than a cut above legends and are in the realm of historical facts and observations.
Great disasters leave their mark in legend, written accounts, and in modern archaeology.
Sifting through this to find truth is not always easy, but taking the easy way out by simply ignoring it all because it would be inconvenient to your world view is not very honest.
When events were written down long after the fact there were procedures in use since Ancient Greece to get at the truth.
https://www.google.com/url?q=http://msi.nga.mil/MSISiteContent/StaticFi…
"Pytheas visited an island six days sailing north of Britain, called Thule. Probably Thule was (part of) the Norwegian coast, although Iceland, the Shetland Islands and Faeroe Islands have also been suggested by historians. Pytheas says Thule was an agricultural country that produced honey. Its inhabitants ate fruits and drank milk, and made a drink out of grain and honey. Unlike the people from southern Europe, they had barnss, and threshed their grain there rather than outside.
He said he was shown the place where the sun went to sleep, and he noted that the night in Thule was only two to three hours. One day further north the congealed sea began, he claimed. As Strabo says (as quoted in Chevallier 1984):
Pytheas also speaks of the waters around Thule and of those places where land properly speaking no longer exists, nor sea nor air, but a mixture of these things, like a "marine lung", in which it is said that earth and water and all things are in suspension as if this something was a link between all these elements, on which one can neither walk nor sail.
The term used for "marine lung" actually means jellyfish, and modern scientists believe that Pytheas here tried to describe the formation of pancake ice at the edge of the drift ice, where sea, slush, and ice mix, surrounded by fog.
After completing his survey of Britain, Pytheas travelled to the Shallows on the continental North Sea coast. He may also have visited the Baltic Sea, but he did visit an island which was a source of amber, probably Helgoland.
No record survives of his return voyage. He may have returned by the way he came; or perhaps by land, following the Rhine and Rhône rivers. "
http://www.fact-index.com/p/py/pytheas.html
I have heard some saying that global warming is rapidly increasing because the amount of greenhouses gases produced in the atmosphere are depleting the ozone layer yearly by 0.5%, is this true?u13127846
Statistically it is said that the ozone layer is depleting at a rate of 0.5% yearly. The CFC concentration in the atmosphere is increasing at an alarming rate and is as a result having detrimental effects on the ozone layer, which is a protective barrier from ultraviolet rays. Without this protective barrier, ice in the Arctic will melt more rapidly thus a rise in sea levels will be expected. This is a dangerous phenomenon and may have large impact on the nearby continents.