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Topic: Record....Cold?< Next Oldest | Next Newest >
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PostIcon Posted on: Aug. 04 2013, 12:27 pm  Skip to the next post in this topic. Ignore posts   QUOTE

http://iceagenow.info/2013....-record

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PostIcon Posted on: Aug. 04 2013, 1:53 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

From that same website referenced in the article you cited (AND NOTED ONCE AGAIN, WITH NO COMMENT WHATSOEVER - TROLLBOY).


Comments:
1) Note variations from year to year.
2) Note trend line.

ETA:
3) Note climate change idiot TROLLBOY.
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PostIcon Posted on: Aug. 05 2013, 9:54 am Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(Gabby @ Aug. 04 2013, 1:53 pm)
QUOTE
From that same website referenced in the article you cited (AND NOTED ONCE AGAIN, WITH NO COMMENT WHATSOEVER - TROLLBOY).


Comments:
1) Note variations from year to year.
2) Note trend line.

ETA:
3) Note climate change idiot TROLLBOY.

Be careful of figures. Why does the chart begin in 1979? Is that when we began taking records, or was that some maximum that makes the subsequent tailing off look more dramatic? Heck, if I looked at the past two weeks of temps in the Northeast, we'd undoubtedly be in an ice age by October.

What I want to know is the average arctic summer sea ice coverage over the past few millennia? I'd think that it'd be "unknown", and that we only began taking measurements in 1979 due to satellites. How much stock do you put in 34 years of data over a millennial scale?

I think a far better measuring stick is the summer melting of the Greenland ice sheet (cue Go Blue...)


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PostIcon Posted on: Aug. 05 2013, 10:42 am Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

I wasn't going after a "definitive" data collection - I was simply stating the obvious: that the TROLL was talking about variations from year to year, and the important factor is "trend" over the long haul.

Your point is well taken, but I think there has been enough data - that just about anyone but a "denier" should be familiar with by this point - and it wasn't necessary to repeat that here just for the purpose of telling a blatantly stupid TROLL where to get off, but whatever - here you go:

Fig 1: Arctic sea-ice extent and CO2
(a) Time series of annual arctic sea-ice extent and atmospheric concentrations of CO2 for 1900-2007. Sea-ice observations are from the Walsh and Chapman dataset 1900-78, merged with sea-ice concentration retrieved from satellite passive-microwave data (1979-2007) using the NORSEX algorithm, with ice extent updated to 2007. The CO2 scale is inverted.


AND IPCC projections of ice extent based on CO2 concentratiion relationships:

Fig 2: Arctic sea ice in the 20th and 21st centuries.
Annual sea-ice extent 1900-2007 (observed: green, and IPCC modelled mean ensemble: black) and predictions for 2007-50 under IPCC projected CO2 scenarios. The ensemble mean of 15 IPCC numerical-model experiments are thick lines: B1: blue; A2: red.
Shading indicates ±1 s.d. uncertainty.

Projections based on empirical relationship are thin lines, B1: blue; A2: red. The projections are based on a linear regression of CO2 and sea-ice extent data from 1961-2007. The empirical projection does not include natural fluctuations that would be superposed on the trends, as seen in the observations (green).


from this article, which discusses "mirroring" of ice extent and atmospheric CO2 increase, which apparently has a correlation of something like 90%:
"Predicting the advent of the Blue Arctic Ocean"

ETA: Yes, I too noticed the discrepancy between the lefthand scale of these graphs from different sources, and I'm looking into that...

GoBlue is definitely a much better person to do this sort of analysis, but I believe - just after an initial look - that the discrepancy in the scales on these charts is a matter of the first chart measuring "minimum extent" ("the sea ice area that 'survived' the summer melt in the respective years") while the other 2 are using a different kind of measure (perhaps "averaged ice extent"?).

Given my relative lack of familiarity with the technical details, I'm not sure. Reading the above article, it's clear, however, that there are "minor complications" - one clue would be the discrimination in the article cited above between "first year ice" and "multi year ice", which would lead one to deduce that the "extent" values on the lefthand scale represent (millions of sq. miles) something different than the "minimal ice extent" values (which clearly would not include "first year ice", being "end of summer minimums") of the first graph's scale, which is also in "millions of sq. miles".

This chart, for instance, shows "Average Monthly Extent":


Again, the thing to note, IMHO, is the trend, not the yearly fluctuations. Most graphs (presumably) don't show earlier data for the good reason that the trendline was relatively flat until the 1950s, then began a rapid descent.

FINALLY: It would be nice if there was a sort of "demerit system" for those who throw this kind of crap out here, like so much "litter", without comment and without support and without any personal commitment whatsoever. I know it's "trolling", and I know it's more an indication of crass ignorance and willful maliciousness than anything else. This guy simply wants to stir things up and "watch what happens". He doesn't have any expressed interest, and almost certainly doesn't care about anything other than "creating a stir" - it's a right wing ploy that's used repeatedly as a part of the "tell a lie often enough and a lot of people will begin to believe it" strategy. There's very little regard for the truth, or for actually engaging intellectually or otherwise. Sadly, many don't either have the time or the inclination to understand enough about most subjects to know better than to fall for this crap.
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PostIcon Posted on: Aug. 05 2013, 12:23 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

No one ever mentions the mini ice age from the mid 1200's to the 1500's.  

If we had records wouldn't the chart go the other way?

Then there was a period of not much movement for 200 + years.....

Cyclic?
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PostIcon Posted on: Aug. 05 2013, 1:24 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(bbobb169 @ Aug. 05 2013, 11:23 am)
QUOTE
No one ever mentions the mini ice age from the mid 1200's to the 1500's.  

If we had records wouldn't the chart go the other way?

Then there was a period of not much movement for 200 + years.....

Cyclic?

Saying "no one" is a severe distortion of the facts.

The assessment of the LIA indicates that it was a local, rather than global, phenomenon, and may have been the result of anomalous activity, just as the lag in ice extent this year was the result, so I read, of a particularly cloudy period in June. If you read one of those articles I cited, you'd find that a subsequent single week of sunshine was almost enough to return this year's summer to virtually the same level as 2010.

And, of course weather phenomena are "cyclic"! Look at the charts reproduced above! The small daily, monthly and yearly cycles are cyclic, as you must certainly know (summer, fall, winter, spring), and the longer effects are the same. As I understand it (keeping in mind that I'm clearly not at all an expert, of course), some of our current changes are the result of shifts in the jet stream position: higher in the North American continent, lower in the European continent.

What's dramatically obvious about all of this is the Keeling Curve. If given that kind of data without any other clue of what might be going on here on earth, you'd think that the proverbial Martian tourist would definitely evidence a case of "raised eyebrows", whatever that would mean for a Martian. An intelligent being from another planet would almost be sure to ask "What's changed to cause this?"

What's most surprising is that there is a fairly large contingent of earthlings who apparently think there's nothing strange going on at all...

So, here we go, playing the "game" again, for the amusement of TDale, the TROLL.

Well, what has changed to create that "hockey stick" diagram? Any clue?
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PostIcon Posted on: Aug. 05 2013, 2:17 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

A couple things about this.

First, the word "record" in the OP is just an exaggeration from the term "unprecedented" in the blog, which itself is an exaggeration of the data.  Yes, July 2013 was chillier than 2012.  But "unprecedented"?  Look at the same data in, say, 2010...

Huh, it was even chillier of a summer in 2010 than 2013 has been (compare to the link in the OP).  Hardly unprecedented though.  Weather varies dramatically from one year to the next, that's nothing new.


So we have to talk again about the issue of "weather" vs. "climate."  July is just one month.  2013 is just one year.  Even though sea-ice isn't the exact same as weather/climate, in the Arctic the two are inextricably linked, so it's worth a relevant comparison.  When the record minimum sea-ice extent of 2007 happened (blowing out all previously measured records), it surprised a lot of people.  When 2008 showed larger sea ice extent, and even higher slightly-still in 2009, the interwebs blew up with claims that sea-ice was "making a dramatic recovery!" and its decline was fear-mongering hogwash.  But those actually studying sea-ice saw the trend wasn't reversing at all, the ice was still thinning and getting weaker, and it'd just take another big warm summer over the Arctic Ocean to melt it far back again.  And whammo, just like expected at some point, summer 2012 happened.  If you don't believe another big melt will happen again before 2020, I've got an historic bridge in Manhattan for sale at bargain prices.

The temperature trends are still going up.  The climate is warming (different than the short-term weather), especially in the Arctic.  Despite a "chillier than average" single month of July 2013, sea-ice is still trending far below average right now (although still not below last year's huge 2012 record).  Not what you'd expect if it were a "record" cold summer.  (Hint: it isn't a record cold snap.  And it's not terribly unprecedented.)  You'll notice the decline slowed a bit during the "cold" Arctic July.  Not enough to reverse any trends, but slightly-less rapid decline than last year.

NSIDC Daily Arctic Sea Ice Extent

And, Greenland (which certainly doesn't cover the whole Arctic but is a major-enough part of it to be another proxy) is still melting at or above average melt extent this summer, despite the "cold" July.  Again, hardly unprecedented.  And not "unprecedentedly cold."

NSIDC - Greenland Ice Sheet Today

The blog in the OP is simply saying "look, temps were chilly last month!  Climate can't be warming!"  Weather and climate are two different things on two different scales.  Given that the blog in the OP is trying to promote and sell a book predicting that the next ice age is just around the corner, you have to wonder if they have an agenda to push by using terms like "unprecedented cold!" to describe what's been an otherwise unastonishing summer.

I'll just leave with this tidbit, always applicable to discussions like this, for those who still don't get the difference.


- Mike


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PostIcon Posted on: Aug. 05 2013, 2:40 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(bbobb169 @ Aug. 05 2013, 10:23 am)
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No one ever mentions the mini ice age from the mid 1200's to the 1500's.  

If we had records wouldn't the chart go the other way?

Then there was a period of not much movement for 200 + years.....

Cyclic?

Lots of people have "mentioned" that, all over the literature.  Simply, if you believe pundits in the blogosphere who like to say "no one talks about it," without bothering to check a little deeper for yourself, you're naturally prone to believe that.  Google Scholar is your friend (or Web of Science, if you have access).  Verify such claims before auto-believing them, it'll serve you well.

Just one recent peer-reviewed paper, for instance (note: This is the American Geophysical Union's summary of a peer-reviewed article, not just some random guy's blog somewhere who claims that no one else is talking about it):

"Unusual volcanic episode rapidly triggered Little Ice Age, researchers find"
http://www.agu.org/news/press/pr_archives/2012/2012-05.shtml


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PostIcon Posted on: Aug. 05 2013, 2:52 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

While this may not be a good example, I believe continued melting of the polar ice will eventually dilute the oceans near the poles, disrupting normal current flow and spawning a new ice age.

I think our planet is a lot better at regulating it's temperature than we give it credit.
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PostIcon Posted on: Aug. 05 2013, 3:04 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(Lamebeaver @ Aug. 05 2013, 12:52 pm)
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While this may not be a good example, I believe continued melting of the polar ice will eventually dilute the oceans near the poles, disrupting normal current flow and spawning a new ice age.

I think our planet is a lot better at regulating it's temperature than we give it credit.

That's entirely possible.  Possibly.  Maybe.  It's been theorized anyway.

I'm not worried that life on the planet won't tick on.  It has, through far larger shifts from "normal" than this (any of the mass-extinction events in ancient history allude to that, a 65-million y.o. meteor caused a pretty huge shift in climate for awhile and wiped out 95% of all species on Earth), and Earth ticked on just fine.

It did become quite a miserable place to be though in the meantime.  Stable agriculture (which is necessary for large-scale human survival, unless you want to kill off 95% of us) becomes far harder to manage in a rapidly shifting climate, which hasn't been the norm in our history as a "civilized" species.  Simply saying "the Earth will manage"--which I fully agree with--isn't the same as saying "we needn't worry at all" (with which I wholly disagree).


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PostIcon Posted on: Aug. 05 2013, 3:20 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

If glacial coverage was anything like the last major ice age, a lot of people would be displaced and starve.
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PostIcon Posted on: Aug. 05 2013, 3:28 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(Lamebeaver @ Aug. 05 2013, 1:20 pm)
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If glacial coverage was anything like the last major ice age, a lot of people would be displaced and starve.

Fully agree.  I'm not in a big hurry to artificially push us that way, regardless which way the trends push us down the line.


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PostIcon Posted on: Aug. 05 2013, 4:25 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(Lamebeaver @ Aug. 05 2013, 3:20 pm)
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If glacial coverage was anything like the last major ice age, a lot of people would be displaced and starve.

A lot of people would start shooting and bombing a lot of other people first.

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PostIcon Posted on: Aug. 05 2013, 5:52 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(WalksWithBlackflies @ Aug. 05 2013, 4:25 pm)
QUOTE

(Lamebeaver @ Aug. 05 2013, 3:20 pm)
QUOTE
If glacial coverage was anything like the last major ice age, a lot of people would be displaced and starve.

A lot of people would start shooting and bombing a lot of other people first.

Unlike the shooting and bombing that goes on now.  That's all we need - another excuse to kill each other.
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PostIcon Posted on: Aug. 05 2013, 6:15 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(Lamebeaver @ Aug. 05 2013, 2:52 pm)
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While this may not be a good example, I believe continued melting of the polar ice will eventually dilute the oceans near the poles, disrupting normal current flow and spawning a new ice age.

I think our planet is a lot better at regulating it's temperature than we give it credit.

Wait, what?

I thought arctic ice was sea ice.   In other words, frozen sea water.  How would melting it dilute the sea?
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PostIcon Posted on: Aug. 05 2013, 6:28 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

Sea ice doesn't have much salt in it. Freezing pushes out the salt.

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PostIcon Posted on: Aug. 05 2013, 6:50 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(KenV @ Aug. 05 2013, 4:15 pm)
QUOTE

(Lamebeaver @ Aug. 05 2013, 2:52 pm)
QUOTE
While this may not be a good example, I believe continued melting of the polar ice will eventually dilute the oceans near the poles, disrupting normal current flow and spawning a new ice age.

I think our planet is a lot better at regulating it's temperature than we give it credit.

Wait, what?

I thought arctic ice was sea ice.   In other words, frozen sea water.  How would melting it dilute the sea?

Melting sea ice wouldn't, at least not significantly.  Sea ice has a huge spatial coverage (having tremendous effects on Arctic albedo as a whole), but the ice--by comparison--is pretty thin.  Eco is right that sea ice doesn't have much salt in it, but the effect on ocean salinity from melting sea ice would be negligible, at least in the most-direct cause-effect way.

But LB didn't say "sea ice" in his post, he referred to "polar ice", which I took to include Greenland and/or Antarctica.  If he meant differently he can explain accordingly.  Your question put words into his mouth that he didn't actually say.

Again, I'm not certain that the theory LB outlines is entirely supported by physical evidence (things such as oscillations in the East Greenland Current affect salinity in the Arctic Ocean more in a given year than even big melt summers from Greenland), but it's an interesting process.  I have heard of the theory before, just don't personally know a ton about it.  They do measure salinity though in waters surrounding Greenland, and it does change very measurably during a large melt summer, at least surrounding the island.  Full implications of that are yet unknown, AFAIK (which isn't necessarily saying much, I should add).


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PostIcon Posted on: Aug. 05 2013, 8:07 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

I know nothing of the theory(ies) involved either, though what I have read seems to use the word "thermohaline" quite a bit. I believe the term has something to do with large amounts of rice porridge and large quantities of sewage and refuse originating in New York City.
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(GoBlueHiker @ Aug. 05 2013, 4:50 pm)
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But LB didn't say "sea ice" in his post, he referred to "polar ice", which I took to include Greenland and/or Antarctica.  If he meant differently he can explain accordingly.  

Spot on!

I'm not a climatologist or geologist, but I find both subjects facinating.  Here's a video that explains some of the current theories.

If you're not interested in the historical perspective, you can jump to around 8:50, but the whole thing is rather interesting.  There are many theories...I personally like the "ocean current disruption"

<object width="420" height="315"><param name="movie" value="//www.youtube.com/v/fyXwFK603J4?hl=en_US&amp;version=3&amp;rel=0"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="//www.youtube.com/v/fyXwFK603J4?hl=en_US&amp;version=3&amp;rel=0" type="application/x-shockwave-flash" width="420" height="315" allowscriptaccess="always" allowfullscreen="true"></embed></object>
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(GoBlueHiker @ Aug. 05 2013, 4:50 pm)
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But LB didn't say "sea ice" in his post, he referred to "polar ice", which I took to include Greenland and/or Antarctica.  If he meant differently he can explain accordingly.  

Spot on!

I'm not a climatologist or geologist, but I find both subjects facinating.  Here's a video that explains some of the current theories.

If you're not interested in the historical perspective, you can jump to around 8:50, but the whole thing is rather interesting.  There are many theories...I personally like the "ocean current disruption"

http://www.youtube.com/watch?v=fyXwFK603J4
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PostIcon Posted on: Aug. 06 2013, 10:46 am Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

I am a bit out of time on this and not up on current theories but when I was studying this in the late 90s the then current theory on the Younger Dryas was that it was the result of a the glacial meltwater coming off the North American continent creating a freshwater cap which slowed/reduced/interrupted the thermohaline circulation pattern of North Atlantic Deep Water formation.  This essentially shut off the Gulf Stream and caused Europe to have about 1,000 years of cold weather.

So it would appear that massive melting can cause the problem, however the issue is do we have the volume and rapidity available in Greenland to trigger that.

But in the end what GBH says is the key.

LAST time this kind of crazy stuff happened humans were a SUPER tiny portion of the world and there were not TRILLIONS of dollars of infrastructure in place to get damaged.  And no one farmed either....

So if your concern is limited to the survival of the earth everything is peachy just keep on keeping on it is fine.

However if you have any concern over humans or many animal or plant species then we have a problem indeed.
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PostIcon Posted on: Aug. 06 2013, 12:04 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

At the time prior to the Younger Dryas, there was massively more fresh water sequestered in giant lakes in North America. Keep in mind that the greatly reduced volume of todays Great Lakes are still the largest reservoir of fresh liquid water on earth. If that water was all released in a cataclysmic event, on an even greater scale then the collapse of the ice dam of Lake Missoula that formed the Scablands of the Columbia River Gorge, or Glacial Lake Wisconsin which formed the Dells, and cut the valley of the Wisconsin River, then there could have been a volume of water sufficient to interrupt the thermohaline circulation of the North Atlantic.

ETA: The level of CO2 has been implicated in major climate change, both when geologic weathering removed it from the atmosphere during the build up of land masses, and during the destruction of landmasses. The Deccan Traps, and Siberian Traps, massive volcanic events correlate with mass extinctions. It is not enough to know that there have been many cycles climate change, it is important to know why. We, as a so called intelligent species, successful by virtue of having learned how to manipulate our environment, are the ones arguing about whether we should be cautions about events that we are not certain of the outcome.

There are other factors, tidal, wind, and the Coriolis effect, that a fresh water cap would have to be overcome, and which would restore the circulation given time. I think that those events have happened, but they were the kind of feedback events that caused relapses of glaciation, not the initial trigger of the glaciation. The Milankovitch cycles are the most likely culprits when other conditions reinforced planetary cooling.

While the jet stream is the most erratic influence that is obfuscating the climate trend with variable weather. It is ocean currents that do the heavy lifting in the distribution of heat energy on earth. Don't forget that the lithosphere is another circulation system that recycles minerals, and carbon, but it also rearranges the continents which alters the pattern of ocean circulation.

The worst glaciation ever, occurred during the time of the Rodinia, the supercontinent where all of the worlds land mass prevented ocean circulation to the South Polar region. The volcanic forces the broke Rodinia apart also introduced CO2 to the atmosphere. The supercontinent of Pangea was equatorial, and during those times we have no evidence of glaciation. The highest temperatures we have evidence for were during the break up of Pangea. The circulation of heat from the core of the planet is destructive to supercontinents which form an insulating cap. Today, the arrangements of land masses limit ocean circulation to the polar regions to the extent that other causes of climate forcing have more influence than at other times during the Earth's natural history.

Our species now number seven billion, a result of our ancestors having survived countless bottle neck extinctions. Our intellect and technology have been derived so that we could dominate nature. Why is it so hard to acknowledge that we have succeeded at dominating nature with only a poor understanding of the unintended consequences?


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PostIcon Posted on: Aug. 07 2013, 1:10 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

Just in case folks are interested about what's actually going on in the Arctic climate, here's the latest NOAA "State of the Climate 2012" report, released this month, by the folks that collect the data, review it thoroughly and publish the actual findings, rather than some blogger's spin from one month:

BAMS State of the Climate 2012 Report

Or, if you'd rather get the Cliff's Notes version, here's an article about the report, or the parts of it related to the Arctic:

http://www.theguardian.com/world....-change


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PostIcon Posted on: Aug. 07 2013, 1:29 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

Except for a few years of rain, it's been getting much drier and hotter in the west.  The trends over decades or centuries are up for debate but in the "here and now", reservoir levels are at lows (lake mead to elephant butte) and much of our high altitude forest has burnt before rainy (monsoon) season.  If I still remain here, I'll take a cue from more of my friends increasingly taking their family vacations in the wet northeast.  So looking at a reversal of tourist bucks from what should be but there it is.  Another concern is real estate.   More towns are running out of water (Monticello, NM, recently), making me loathe to purchase real estate if water rates will go sky-high.  

There's still a rainy season but on a low snow year, hiking and backpacking may be curtailed until late summer/early fall.  Of course you could just take a chance with your tourist bucks...


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PostIcon Posted on: Aug. 07 2013, 1:46 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

If anyone wants to play with the data themselves and see what it's actually saying, you can auto-generate a lot of plots directly from the NOAA Climate Monitoring website.  It's good to spend a bit of time looking at the data yourself.  Again, it's better than blindly trusting a blogger's spin about it and looking no further, or anyone's posts here, for that matter.  Look at the data personally.

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PostIcon Posted on: Aug. 08 2013, 9:00 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(GoBlueHiker @ Aug. 05 2013, 6:50 pm)
QUOTE

(KenV @ Aug. 05 2013, 4:15 pm)
QUOTE

(Lamebeaver @ Aug. 05 2013, 2:52 pm)
QUOTE
While this may not be a good example, I believe continued melting of the polar ice will eventually dilute the oceans near the poles, disrupting normal current flow and spawning a new ice age.


I think our planet is a lot better at regulating it's temperature than we give it credit.

Wait, what?

I thought arctic ice was sea ice.   In other words, frozen sea water.  How would melting it dilute the sea?

Melting sea ice wouldn't, at least not significantly.  Sea ice has a huge spatial coverage (having tremendous effects on Arctic albedo as a whole), but the ice--by comparison--is pretty thin.  Eco is right that sea ice doesn't have much salt in it, but the effect on ocean salinity from melting sea ice would be negligible, at least in the most-direct cause-effect way.

But LB didn't say "sea ice" in his post, he referred to "polar ice", which I took to include Greenland and/or Antarctica.  If he meant differently he can explain accordingly.  Your question put words into his mouth that he didn't actually say.

Again, I'm not certain that the theory LB outlines is entirely supported by physical evidence (things such as oscillations in the East Greenland Current affect salinity in the Arctic Ocean more in a given year than even big melt summers from Greenland), but it's an interesting process.  I have heard of the theory before, just don't personally know a ton about it.  They do measure salinity though in waters surrounding Greenland, and it does change very measurably during a large melt summer, at least surrounding the island.  Full implications of that are yet unknown, AFAIK (which isn't necessarily saying much, I should add).

Thanks for the clarification. That was helpful.

I was not aware that "polar ice" included Greenland ice.  Arctic ice yes, polar ice, no.  I figured that was why he used the term polar ice instead of arctic ice, to only include the ice at the pole where there is no land.  Sorry if I "put words" in LBs mouth.

As for the salinity variation, that's quite common everywhere, especially where rivers enter the oceans.  There are also significant salinity variations in the open ocean at various depths and at interfaces of large ocean currents, like the Gulf Stream and the Japan Current.
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PostIcon Posted on: Aug. 09 2013, 8:39 am Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(GoBlueHiker @ Aug. 07 2013, 1:46 pm)
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Again, it's better than blindly trusting a blogger's spin about it and looking no further, or anyone's posts here, for that matter.  Look at the data personally.

Pfffff. If we did that, this forum would have no purpose.

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PostIcon Posted on: Aug. 09 2013, 4:47 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE


(KenV @ Aug. 08 2013, 7:00 pm)
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I was not aware that "polar ice" included Greenland ice.  Arctic ice yes, polar ice, no.

Just to be fair, there are no hard definitions of the terms "polar ice" or "Arctic ice", so it's kinda hard to pin a narrow definition on either one.  I took his phrase to mean "ice in the polar regions" (which includes Greenland), you interpreted it more as "ice specifically at the poles".

Other terms in glaciology and polar science have more established definitions ("land ice", "continental ice sheet" (which floating sea ice isn't), and "sea ice") that refer to more specific things.  I don't recall seeing the terms "polar ice" or "Arctic ice" used in current literature.  Scientists generally don't use vague terms when referring to something specific.

- Mike


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PostIcon Posted on: Aug. 09 2013, 5:18 pm Skip to the previous post in this topic. Skip to the next post in this topic. Ignore posts   QUOTE

Just yesterday the American Geophysical Union (AGU) revised their official Position Statement on Climate Change.  For a bit of background, AGU is the world's largest collection of physical Earth scientists, with membership around 60,000 worldwide, studying everything from climatology to geology to atmospheric chemistry to biodiversity to space weather, anything geophysical.

In the recent past the organization took a softer approach, in their February 2012 statement:

QUOTE
Humans Impact Climate, and the Scientific Community has the Responsibility to Educate and Communicate the Implications of Climate Change to the Public and Policy Makers

The scientific evidence for human activity impacting climate is strong and widely accepted within the scientific community. Given the significant current and potential impacts of climate change, scientists have a unique responsibility to educate the public and public policy makers on this topic.


But as the evidence keeps mounting up, making the picture clearer and clearer, they revised their statement to take a much more forward approach that summarizes and reflects the current state of scientific knowledge on the subject.  From their August 2013 Statement (<--- Full 2-page statement here):

QUOTE
Human-induced climate change requires urgent action.

Humanity is the major influence on the global climate change observed over the past 50 years. Rapid societal responses can significantly lessen negative outcomes.

To get a more thorough summary of the scientific knowledge and what the position says, read the full statement linked above.

It's just the latest update, coming from the scientists themselves.

- Mike


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PostIcon Posted on: Aug. 09 2013, 5:20 pm Skip to the previous post in this topic.  Ignore posts   QUOTE


(GoBlueHiker @ Aug. 09 2013, 4:47 pm)
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Scientists generally don't use vague terms when referring to something specific.

Confound them!
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