The Definitive Global Climate Change (aka Global Warming) Thread -- General Discussion and Questions

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TedBundo's picture
TedBundo
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Thanks for that link the

Thanks for that link the articles really made me think a lot and I liked the interactive map. I'd say that climate change is evident where I'm from.... the landscape clearly shows it and our football field at the local high school is dying because of the lack of rain and higher than normal temperatures.

Mark Cochrane's picture
Mark Cochrane
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Perspective on Arctic Sea Ice

Another year of low ice cover in the Arctic. So what's new? Few know about this and fewer care. The decline has been going on so long that we fail to be shocked anymore. In the graph below the gray area is where 95% of years should fall. We are well below that area, yet again, about where we were last year. The dashed line is 2012 when we experienced the lowest sea ice cover (in September). Depending on the vagaries of the weather, this year may or may not be the lowest on record but just looking at the area of cover is misleading, since it tells you nothing about the thickness of the ice.

As the ice cover expands in the cold Arctic winter it covers the ocean and traps the heat it contains. This allows the air temperatures to drop very low above the ice. Think of the ice as the covers on your bed. If your covers are thick your body heat stays contained even on a cold night. If you have just a thin sheet you don't stay quite so comfortable.

In the Arctic, sea ice gets thicker the older it gets as it goes through successive winters. As recently as the 80s, 30% or more of the ice cover was 5+ years old and first year ice was not much different at about 35% of the area. Now, older ice area has been reduced to <5% while first year ice makes up nearly 70% of the area.

Thin ice breaks easier during Arctic storms and, much like crushed ice in your drinks, melts faster. Open water in the Arctic summer enjoys 24 hours a day of sunlight. Ice reflects most of the heat, but open water absorbs almost all of it. This makes the Arctic ocean warm more and more year after year, which in turn makes the formation of new ice in teh winter harder and harder until later in the year, after enough heat escapes the surface waters. That heat plays havoc with the regional weather in the Arctic. The Polar Vortex is weaker and slower to form making it more likely that cold Arctic air will spill out in bursts across North America and Europe.

The 'death spiral' map shows how sea ice volume is circling the drain that will one day, in the not too distant future, end with an ice-free Arctic summer. How much ice have we lost in the last 4 decades? Comparing April 2017 to April 1979, the reduced volume of Arctic sea ice would be nearly enough to cover the entire combined land area of both Canada and the United States with 1 meter of solid ice.

Alas, the only thing poorer than the human race's ability to understand the exponential function and large numbers is its grasp of geography...

Mark

 

 

PaulJam's picture
PaulJam
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Football score analogy

Thanks for you post, Mark - I have a semi-cynical suggestion on how to communicate ice loss:  compare it to average pro football scores:

Take the average minimum extent from the earliest period that we have data for, then calculate how far out on a normal distribution the 2017 ice coverage minimum is in comparison.  If it is +2 SD, then take the average pro-football winning football score, and figure out what the +2 SD equivalent is.  

I'm too time pressed to dig for the football stats right now, but the average winning score is 29 points.  I'd bet that the minimum ice coverage loss equivalent for a winning football score is around 70 or 80 points.

Then if this message is emphasized by the mainstream media (eye-roll), then just maybe people can understand the extremity of the changes that are now afoot.  If indeed we are entering a process of abrupt non-linear climate change (as I suspect/fear), then Guy McPherson is thoroughly vindicated, and we are left with having to be personally satisfied with merely doing the right thing, rather than thinking that there will be any real beneficial outcomes to our actions.  

Looking at this data and thinking about positive feedback loops that are now engaging, it is very possible that we are right now beyond the reach of even a Marshall-plan like response.

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sofistek
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No vindication

Paul

If indeed we are entering a process of abrupt non-linear climate change (as I suspect/fear), then Guy McPherson is thoroughly vindicated ...

Even this would not "thoroughly" vindicate GM. GM's hypotheses are based, in large part, on flawed interpretations of the science and an over-reliance on some anonymous poster (or set of posters) named Sam Carana, who is not averse to, effectively, making stuff up. The notion of non-linear changes have been posited by the IPCC for a long time. We might well be entering such a phase (I don't know) but that does not translate into McPherson's opinion of total extinction by mid-century (or earlier). So, no, it would not vindicate GM.

Tony

PaulJam's picture
PaulJam
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Sam Carana

Tony - I never know what to think about the Arctic News website myself, so am interested in all opinions/thoughts.  I read it often (among other AGW sites) but am left with an agreement with myself to both not fully believe it and yet not dismiss outright.

There are dual tendencies at work when trying to make heads or tails of this stuff - on one hand, the tendency for hyperbole just to make waves and get peoples attention, or simply to indulge an individual's emotional blind spot of self-righteous misanthropy; and on the other hand the tendency to dismiss predictions of the most adverse of outcomes on the basis of the disagreeableness of where the data is pointing.  I don't have the time to dive deeply into the scientific sausage making behind sites like Arctic News, so am left with opinions of others and my own pondering.

 

sofistek's picture
sofistek
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Carana

Paul,

One only has to look at the frequency of Carana's taking a short period of data points and extrapolating, only for the projections to be falsified by the next period of data. Carana leaps on such periods only to pander to the doomers. He or she is also not averse to mixing datasets in one graph or to graph out data points that aren't actually data points. Of course, there will always be the odd bit of interesting opinion amongst all of that but you will rarely, if ever, see critical comments in the comments section, because they don't get published (I've tried many times).

No, if you want reasonably accurate news about the Arctic, try Neven's blog. He's not as prolific as Carana, but there are also some interesting discussions in the comments sections of posts, and in the related forum.

Tony

sofistek's picture
sofistek
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One to go

Deniers and contrarians have been relying on data series that don't measure surface warming, which, for the lower troposphere, have shown a smaller warming trend than surface measurements. The RSS TMT data set was corrected a couple of years ago and now it's the RSS TLT data set. Well, once biases have been removed, TLT shows an even stronger warming than surface records, though still not as strong as some models suggest.

I'm now waiting for the usual suspects to tell us why this is a conspiracy or why their last remaining hope, the UAH TLT data set (currently still in a beta version), is a far better measure.

I'm not sure what data set Mark and Stan agreed on for their bet but it's sure starting to look like a lost cause for Stan.

Tony

Time2help's picture
Time2help
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Data Point

Here's a new data point. Record dry spell out here in on the West Coast. Now it's burning.

http://cliffmass.blogspot.com/2017/09/smoke-front-hits-western-washingto...


 

sofistek's picture
sofistek
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Contrarian Arguments Examined

This recent paper by Benestad, et al, examines many contrarian papers (the ones outside the 97% concensus) and explains the errors in them. Perhaps the contrarians ought to now examine this paper to see if there are errors in the analysis?

Good luck.

Tony

SSTP's picture
SSTP
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Posts: 2
Cyclical?

I remember my professor made a similar argument 12 years ago or so in University...
What do we think? apologies if this has already been discussed or shown, big thread to get through!


 

SSTP's picture
SSTP
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Cyclical?

...I see cycles have been brought up, starting from the first page :)

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