they predicted that Antarctic sea ice would increase in a warming world

But they DIDN'T predict growing sea ice in a world that is NOT warming, did they? [Jane Q. Public, 2015-05-22]

Good grief, Jane. They also didn't predict growing sea ice in a world that's infested with leprechauns. But neither of those silly objections are relevant, because the real world is warming. Remember?

"We know the Earth is warming, you idiot. That's not the issue here." [Lonny Eachus, 2010-07-01]

Since these conditions are not the conditions presumed in the model, in fact they have not predicted anything. You are just a master at inappropriately shifting contexts, as I have pointed out many time. You don't get to say that they predicted a result given THESE conditions, then say the same result under OTHER conditions constitutes a "prediction". Especially given the uncertainties involved. That's bullshit. [Jane Q. Public, 2015-05-22]

Nonsense, Jane. Manabe et al. 1991 predicted that increasing atmospheric CO2 warms the planet and causes a slight increase in Antarctic sea ice. This certainly constitutes a prediction because these conditions are happening. After all, as you've said, nobody is denying it's warming.

The next time you want to keep ignoring the predictions of Manabe et al. 1991 and all these other confirmed predictions, it might be more honest to just say that you reject all those confirmed predictions, rather than trying to pretend that they never happened.

You aren't using "all the available data". Once again, you are using the data that is convenient to you. ... [Jane Q. Public, 2015-05-22]

That's absurd, Jane. I've repeatedly linked to Polyak et al. 2010 and Kinnard et al. 2011. Polyak et al. reconstructs Arctic sea ice back to 1870, and Kinnard et al. goes back 1,450 years.

... I will ask you again: would the slope be the same if you chose 2000 for a starting point, or 1850? No, it would not. I made a simple comment based on a simple fact: 1981 was at or near a local maximum, and using it for a starting point of your "average" is questionable at best. That is an accurate statement. If you chose 1930 instead, as another local maximum you would again have to justify that as a starting point. You don't get to weasel out of that. [Jane Q. Public, 2015-05-22]

I don't have to "weasel out" of anything, because despite your baseless accusation I've always advocated using all the available data. In the context of using a single dataset, that means not cherry-picking the starting point, and instead using the entire dataset.

That's why it was so baffling when Jane baselessly accused Layzej of cherry-picking when he loaded the entire UAH dataset, then Jane suggested only using data since 1998. Jane was the only person in that conversation who suggested cherry-picking a starting point, rather than simply loading all the data in the dataset. Then Jane did it again.

And now Jane keeps asking what starting point I would use. Again, I wouldn't cherry-pick a starting point. I'd load the entire dataset into the trend analysis code I've already shared with Jane. Here's that example. The black line on the second page shows the UAH trend ending in 2012, for different starting years. The error bars are shown in red; they're 95% confidence uncertainty bounds.

Note that my analysis uses the entire dataset, and allows one to immediately see the calculated trends and uncertainties for many starting points at once, going all the way back to the first value in the dataset.

If you'd like, I could modify that code to load Arctic sea ice extent data, then share the new code and results with you. Or maybe you'd like to show off your programming skills instead? Either way, just let me know what dataset you'd like to investigate and we could actually start analyzing that entire dataset, with no cherry-picking of starting points at all.

But I doubt we'd find much support for Jane's claim, because neither this graph of the NSIDC Arctic sea ice index or Polyak et al.'s Fig. 2(a) show a clear local maximum in 1981 or 1979, either for the minimum or maximum sea ice extent.

... I will ask you again: would the slope be the same if you chose 2000 for a starting point, or 1850? No, it would not. I made a simple comment based on a simple fact: 1981 was at or near a local maximum, and using it for a starting point of your "average" is questionable at best. That is an accurate statement. If you chose 1930 instead, as another local maximum you would again have to justify that as a starting point. You don't get to weasel out of that. [Jane Q. Public, 2015-05-22]

Jane introduced "1981" here which seems to be a reference to this NSIDC Arctic sea ice extent plot. Once again, Jane hasn't actually presented any evidence that 1981 was at or near a local maximum. But let's humor Jane and pretend that 1981 was a really huge local maximum for Arctic sea ice extent. NSIDC calculated the average Arctic sea ice extent from 1981-2010. As Jane asks, would the slope be the same if the NSIDC chose 2000 for a starting point for their average? (*)

If the NSIDC chose to use a 2000-2010 average, that wouldn't change the calculated trends/slopes like these on page 2 here. That's because the NSIDC isn't cherry-picking data starting points when they use a 1981-2010 average. They're still using all the data, but just comparing that data to an average over 30 years.

Sadly, many people seem to be confused about calculating an average and using it as a baseline.

That's why I've said that confusion regarding baselines makes me think that plotting the trends and error bars is better than plotting the timeseries with an "ideal" baseline. Since the trend is the time derivative of the original timeseries, the constant baseline is irrelevant.

Another way of appreciating this point would be to notice that absolutely nothing would change on this NSIDC Arctic sea ice extent plot if that hypothetical really huge local maximum happened in 2010 rather than 1981. Again, that's because the NSIDC isn't cherry-picking data starting points when they use a 1981-2010 average. They're just calculating an average, so whether the maximum occurs in 1981 or 2010 is irrelevant.

Once you realize that the NSIDC is just calculating an average, it should be clear that the most important criterion is how long a timespan that average covers. That way, a hypothetical really huge local maximum gets averaged together with other years. I've said that I like plots with 30 year baselines because that's long enough to define the climate. Since that NSIDC plot uses a 30 year long baseline, it seems okay to me.

Jane, can we agree that a 30 year baseline is better than a 10 year baseline (like 2000-2010) or even a ~1 year baseline because longer baselines average out more weather noise? Can we agree that any choice of baseline is irrelevant to calculating trends/slopes like these on page 2 here?

(*) Obviously the NSIDC couldn't choose a starting point of 1850 on their satellite data plot because the modern satellites were launched in ~1979, but it seems unlikely that Jane will ever concede that he was wrong to insist that "your precious warmism sources consistently start THEIR charts in 1979, and if that isn't cherry-picking, nothing is."

Once again, this is completely backwards. In the context of using a single dataset, loading that entire dataset isn't cherry-picking. Arbitrarily cherry-picking a starting point of 1998 is cherry-picking. This isn't complicated, Jane.

If you should ever start actually using "all the available data", and were honest with yourself, I think you might start softening your tone. [Jane Q. Public, 2015-05-22]

Once again, Jane's concern about my tone is incredibly ironic. And Jane, keep in mind that you were cussing and insulting me while defending your Latour nonsense... which you finally admitted violates "kindergarten-level physics".

But you obviously can't admit your "silly gradeschool-level" mistake, even after defending it while calling me a goddamned stupid dumbshit despicable human being fraudulent dishonest lying fucking moron idiot asshole malicious lying sonofabitch.

After all that, don't you see even the tiniest bit of irony when you criticize my tone and repeatedly claim to be happy to admit your mistakes?

The problem is, sewage treatment systems have a lot of trouble (at present, let's just simply say "can't") filtering them out. They go into the sewage, they will go into the sea.

Setting up filters for particles as small as 1 micron for all sewage going out into the ocean is obviously going to be a massive expensive. Who wants to pay for that so that people can keep sticking bits of plastic in cosmetics?

Seriously, whose bright idea was it to make bits of plastic, bite-size for plankton, looking like fish eggs, whose very design intent is to wash out into the ocean? And no, while they're not harmful to us, they absolutely will be to plankton - if not immediately (how healthy do you think you'd be if you wolfed down an entire meal-sized chunk of plastic?), then with time. Plastics act as chelators for heavy metals and a number of organic poisons, to such a degree that they might even be economical to mine. There's simply no way that this isn't going to have an impact.

And it's so stupid when one can just use soluble crystals (salts, sugars, etc) instead of plastic.

That doesn't explain record sea ice extents at a time when it is claimed that ocean, not particularly land, temperature is increasing. I'm not trying to claim it's irrelevant. But it certainly does not seem sufficient. [Jane Q. Public, 2015-05-22]

There are reasons to doubt the land ice melting connection to Antarctic sea ice, but I don't think that's one of them. I mentioned real reasons by citing Swart and Fyfe 2013, Polvani and Smith 2013 and referencing fig. 2 and fig. 4(e) from Parkinson and Cavalieri 2012 (PDF).

But ocean warming is sufficient to thin West Antarctic ice sheets, as I've explained:

"West Antarctica is among the most rapidly warming regions on Earth, with an ice sheet that's vulnerable to the warming oceans because it's mainly grounded below sealevel."

"Because West Antarctica juts out into the Antarctic Circumpolar Current (ACC), those warming waters are thinning its ice sheet at an accelerating rate. ... Its ice sheet is also mainly grounded below sealevel, making it more vulnerable to the warming oceans than the East's which is mainly grounded above sealevel."

The fact that West Antarctica is mainly grounded below sealevel means that ocean warming causes rapid land ice thinning there. Also, the fact that the bedrock is deeper farther inland from the grounding line has "interesting" consequences. See Rignot et al. 2014 and Joughin et al. 2014.

Manabe was 14 years ago. Conditions have changed rather significantly in that time, as has our understanding of the geology. It may be that Manabe is still correct. On the other hand, it may not. [Jane Q. Public, 2015-05-22]

No, Jane. Manabe et al. 1991 was 24 years ago. The fact that Manabe was 24 years ago is exactly why I've repeatedly showed it to you. They predicted that Antarctic sea ice would increase in a warming world, but you keep insisting that "The science is faulty at its roots. The models haven’t predicted one thing, in 30+ years. ... You don’t really need to know anything about the science except that IT HASN’T PREDICTED ANYTHING. That makes it bad theory. ... CO2 warming theory has predicted NOTHING."

In addition to the other 17 reasons I gave you, don't you think this is another reason you should reconsider making these baseless accusations?

I've told Jane and economart that Fig. 2(a) from Polyak et al. 2010 shows that the reconstructed Arctic sea ice extent in the 1930s was comparable to that in 1979, and the modern decline is quite clear.

You seem to feel that what "you told people" is necessarily truth. That's an interesting point of view. [Jane Q. Public, 2015-05-22]

Huh? Jane, I just gave you links to peer-reviewed long-term reconstructions of Arctic sea ice extent in response to your insinuations that scientists are deliberately misleading. In response, Jane tries to guess at my feelings about what I "told people".

Instead, you might find it more productive to click on those links and learn about peer-reviewed long-term reconstructions of Arctic sea ice extent. Then maybe you'll be in a better position to judge whether you should dare to accuse scientists of deliberately misleading.

I've also repeatedly explained that Jane's accusations of deliberately misleading cherry-picking are completely backwards. As usual.

You are implying that my statement that 1981 was near a temporal local maximum is incorrect? You would rather use 1930 as your starting point? As opposed to, say, 2000 or 1850? [Jane Q. Public, 2015-05-22]

Good grief, Jane. Once again, I'd rather use all the available data. In the context of using a single dataset, that means using all the data in that dataset. That's why it's so ironic that Jane baselessly accused Layzej of cherry-picking when he loaded the entire UAH dataset, then Jane suggested only using data since 1998. But Jane obviously won't ever be able to grasp this irony, because he just did the same thing again.

In a broader context, a single dataset is just part of the picture. That's why I linked to longer-term reconstructions like Polyak et al. 2010 and Kinnard et al. 2011. In both papers, the modern decline in Arctic sea ice is quite clear. It's not clear that 1981 was near a temporal local maximum in Polyak et al.'s Fig. 2(a), either for the minimum or maximum sea ice extent. It's not even clear that this changes if we instead take seriously Jane's previous accusations that scientists "cherry-picked" data from 1979 instead of 1981.

...antarctic sea ice is at or near a record high... [Jane Q. Public, 2015-05-22]

I've repeatedly told you this is consistent with Manabe et al. 1991 page 811: "... sea surface temperature hardly changes and sea ice slightly increases near the Antarctic Continent in response to the increase of atmospheric carbon dioxide."

... it's a bit of a mystery to me how they can claim that ice is melting due to unusual ocean warming, when we know that ocean surface ice has been at record levels. [Jane Q. Public, 2015-05-22]

I've explained that Manabe et al. attributed the slight Antarctic sea ice increase to increased precipitation in the area. This freshens the frigid surface water and reduces mixing with the warmer water below. Other possibilities include stronger winds which spread out the ice and expose more surface water to be frozen.

Correction: arctic ice is below 1 standard deviation from 1981-2010 average, but within 2 std. deviations. Still, remember that 1981 is a (dare I say deliberately chosen?) high point from which to start measurements, so going by the 1981-2010 average is probably a bit misleading. And the total global ocean ice is still well above normal, because of the record high Antarctic ice right now. [Jane Q. Public, 2015-05-22]

I've told Jane and economart that Fig. 2(a) from Polyak et al. 2010 shows that the reconstructed Arctic sea ice extent in the 1930s was comparable to that in 1979, and the modern decline is quite clear.

I've also repeatedly explained that Jane's accusations of deliberately misleading cherry-picking are completely backwards. As usual.

If it were in existence ~1400 years ago, perhaps we would have nipped Islam in the bud.

If it were in existence ~2000 years ago, perhaps we would have nipped Christianity in the bud.

And I wonder how many readers agreed with my first line, then threw a shit-fit when they got to my second line.

-

The article is also based on some terrible reasoning, like:

That means there will be no asteroids left in the Solar System, because they all will have struck Earth, in another few hundred million years. Think someone’s overestimated something there? Yeah, me too. Let’s take a look with the flaws in our fear-based reasoning.

Yeah, in a universe where our solar system is some sort of perfect steady state. Which, of course, it is not. Asteroids collide or - more commonly, come close to other bodies and gravitationally interact - and throw each other into different orbits. When that happens, non-Earth-crossing asteroids can become Earth-crossing ones. For example, one of the candidates for the K-Pg extinction event is a Batisma-family asteroid. This family came from an asteroid breakup 80 million years ago.

A person well versed in the field would be aware of the fact that asteroids are not in some sort of unchanging steady state. Which is why they're the ones paid to do the research on the subject.

And more to the point, we really don't have a good handle on what's out there. We have trouble making out dwarf planets in the outer solar system. We really have no bloody clue what could be on its way into the inner solar system, apart from studying how often major events happen.

And on that note, another flaw in his logic, given that until recently, the vast majority of Tunguska-style events would never even have been detected, having occurred over the oceans, remote deserts, the poles, etc. So by all means it's perfectly fair to say that the fact that an asteroid hitting earth is more likely to hit a remote uninhabited area is perfectly fair. But saying that while mentioning the rarity of inhabited areas having been hit in the past is double-counting. The historical record is evidence of how often they hit populated areas, not how often they hit Earth.

Lastly, his claim that only one person has ever been "hit by an asteroid" is ridiculous. 1500 people were injured by the Chelyabinsk one in 2013 badly enough to seek medical attention. Yes, they weren't "hit by rocks", but that's not what large asteroid impacts do; they mostly or completely vaporize by exploding in the atmosphere and/or on impact. And there's lots of reports throughout history of people getting struck by asteroids; just because they weren't documented by modern medical science doesn't mean it never happened. Seriously, what's the bloody odds that the only person to ever in historical times be hit by an asteroid would be in the 1950s in the middle of a first-world nation? Now what's the odds that someone being hit in the 1950s in the middle of a first-world nation would be well documented, publicized, and believed?

Just a lot of really bad arguments.

Go to a library.

Politics is all about points of difference, no matter how trivial, without those points of differences there would be no need for politics.

Although there have been threats to do so, this isn't happening in Oz any day soon, the court specifically warned the MAFFIA not to use US style extortion letters. Any letters they send must be pre-approved by the court. If they do it now they WILL be held in contempt and possibly disbarred for abuse of process.

that brain teaser has been around for what, eons now?

I literally (not figuratively) cannot remember when I first heard that one, but I was using it to get a friend's head around spherical geometry in the mid-1980s, so I knew it long before then.

I'd finger Eratosthenes as the guilty party. Or a close contemporary.

He was lying. [aside]You can tell when politicians do that by checking to see if their lips are moving.[/aside].

What a refreshingly open and honest political culture you have. Here, we can tell when our politicians are lying by their not being decomposing into putrid puddles of greasy bones. The only honest politician is a dead one. Dead and clearly decomposing.

tasteless hops to make their piss water.

"their diabetic horse's piss", please. Go the whole hog on the (entirely justified) insult.

(The version I'm thinking of is $BIG_MERKIN_BREWERY$ sends crate of it's best product to Czech brewery $BIG_CZ_BRAUERIE$. Some weeks later a reply is recieved at $BIG_MERKIN_BREWERY$, which is opened with excitement : "Dear Sirs. We regret to inform you that your horse has diabetes.")