songster

Because there are only so many ways you can say "probably, but nobody knows how" without resorting to interpretative dance.

Hasn't this already been done?Fawcett, 2007 (page 140 onwards) http://www.amos.org.au/documents/item/82 Foster and Rahmsdorf, 2011 http://iopscience.iop.org/1748-9326/6/4/044022 Discussion at SkS and Tamino http://www.skepticalscience.com/print.php?r=38 http://www.skepticalscience.com/foster-and-rahmstorf-measure-global-warming-signal.html http://tamino.wordpress.com/2011/12/06/the-real-global-warming-signal/

Feel free :-)

Sea ice linking up to South America would have no effect at all on the ocean currents, since sea ice is (in context) a wafer thin skim on the surface. Similarly, you can't keep a cat still by balancing a Pringle on its back. Edit: If you meant a land link, then that would likely have the effect of melting the Antarctic ice cap. Isolation of the continent by the Circumpolar current after the Drake Passage opened up is believed to be one of the major drivers behind Antarctica becoming glaciated. If you block the circumpolar current, the continent's no longer isolated, you get much more heat influx, and the ice will melt down.

It's an inevitable consequence of the fact that last year was a record low for summer ice. Given that winter extent is much less variable, a higher proportion of it must therefore be newly formed first-year ice.

Where "intense" = "below average"? http://nsidc.org/greenland-today/images/greenland_melt_area_plot_tmb.png

Not for long... http://nsidc.org/greenland-today/images/greenland_melt_area_plot_tmb.png

While the floating ice sheet itself doesn't add to sea level when it breaks off, while it's attached, its sheer mass acts as a kind of "plug" slowing down the flow of the land-based glaciers feeding the sheet. Now that the PIG has calved, look for the flow rate of the PIG to increase. This is where the feedback increase in sea level rise comes from (bearing in mind the fact that any individual glacier's contribution is very small).

When you consider the mass of ice involved in an ice sheet that thick, I doubt the weather has any influence at all - certainly the presence of sea ice will be irrelevant. Tides might possibly affect the timing of the fracture, anything else just has too little energy.

http://xkcd.com/386/ :-)

Well that's kind of my point. Someone posted a graph showing (modelled) temperatures which were below normal but above zero and claimed that the graph proved the Arctic was not melting. It doesn't. Above zero is above zero! Everyone is entitled to their own opinions, but not to their own melting point of water.It looks to me as though the mods have set up a situation where no mistake can ever be set straight within the threads in question. I'm all for discussing ideas which may be a bit off the wall - but creating an environment where the only allowed response is "Yes, I agree totally" is not a discussion.

What happens if someone posts in one of the special three threads, saying "The Arctic ice is disappearing because little green men are eating it to sharpen their teeth" ? I hope we can all agree this is inaccurate! a) Nobody is allowed to contradict them. Only the mods are allowed to correct/remove the post. c) Sceptics are allowed to contradict them in the sceptic thread, AGW-ists in the AGW thread, but not vice versa. d) Anybody is allowed to contradict them. If (a), I tremble for humanity. If ( you've made an awful lot of work for yourselves, and the discussions will depend on which mod is on duty, their beliefs, and how much they know. If ©, where is the list of who's in which category? If (d), then how do the mods decide which posts are inaccurate enough to allow members to contradict them?

I have done so, indeed I did before posting, and I'm none the wiser. I was not arguing with anyone - I wasn't expressing any opinion one way or another as to whether AGW exists or not, and whether it's man-made or not. What I did was point out that one of the data sources referred to didn't show what was being claimed. I've done the same in various Arctic ice threads whenever pro-AGW people make mistakes or misunderstand their sources. Will I end up banned from both threads if I correct people on both sides? I understand the need to keep opinions separate, but this was not a matter of opinion. Indeed, if the same post had been made by someone else like Jethro, doubtless it would have stayed.What happens when a new person joins these boards? Do the mods have to watch them for a while and then (secretly) decide which posts they're allowed to contribute to? Where is the list of who's a sceptic and who's a warmist? A half-assed measure like this is ridiculous. If the intent really is that people can only post in one thread or the other, no matter what, then they should be implemented as members-only forums. As it stands you're just making more trouble for yourselves.

OK, here's a perfect example. http://forum.netweather.tv/topic/76448-scepticism-of-man-made-climate-change/page-11#entry2732662 Keithlucky posted the DMI temperature graph in the "sceptic" thread and said there was no melting north of 80 degrees. I followed up, politely pointing out that that this was wrong for three reasons: firstly that DMI temperatures are a model rather than data, secondly that even though temperatures are below average, they are still above melting point, and thirdly that the mass balance buoys in the area do indeed show both top and bottom melt in the area above 80 degrees. Everything I posted was factually accurate and presented politely. My post has vanished. What is going on? Is nobody allowed to post even verifiable, neutral facts in these threads unless they are somehow (by whom?) registered as official sceptics? How can people be allowed to post mistakes (note, I do not say lies, I say MISTAKES) without these being set right? What are we trying to create here, simply a set of parallel echo chambers and mutual suspicion? Edit: At the very least I would appreciate a private mail from whichever mod deleted my post, saying why they did so and what rules I've infringed.

Not by me *shrug*

And it's a model, not data.

The guy's an idiot, and so are the people that judged the competition. Edit: No doubt someone will ask why, so here goes. 1) It's far too large to sanely construct in the Arctic. It's ~150 metres tall, even leaving aside the umbrella cover. That's close to the size of the Gherkin - and you want it to float? Some oil rigs get close to that size, but they have an open superstructure to stop themselves being capsized by the wind. This proposal has a closed umbrella cover - there's no way you could make it stable. 2) It's far too small to make any impact whatsoever. The Arctic ocean is 14 million km^2, each of these structures will shade around 0.16 km^2. The numbers needed to make a difference are astronomically high. To put it in other terms, London is around 0.1% the area of the Arctic ocean - this means that to shade 0.1% of the Arctic ocean, you need to build another London at the North Pole. 3) It won't work even in principle, and will in fact make things worse. Apparently the umbrella is supposed to shade the ice and absorb the "ultraviolent" energy. So, where does that energy <i>go</i> after being absorbed? Use it to power your research base? Sure, and that means it ends up as heat. <i>Whatever</i> you do with that energy, ultimately it will end up as heat, unless you've found a magic way around the second law of thermodynamics. The only way to have an actual effect would be to reflect the energy, not absorb it - and do so more effectively than the bare snow and ice. Snow has a really high albedo - pretty much any structure you put on it will only mean you absorb more energy, not less.

He's parroting posts from Steve Goddard's blog. Steve regularly posts sarcastic photos of the Greenland ice cap and witters about crops, in the mistaken belief that it makes some kind of point.

Going for 4 million as I think there will be a bit of a bounce back from last year, but 2007 (the previous floor) is likely the ceiling from here on in.

GW, although that's indeed dramatic, as others have pointed out we really cannot compare to previous years since we don't have comparable satellite imagery (because the satellite with that wavelength only went up last year). If you look at the overall Arctic mosaics from this year and others (they have back to 2009 on record, I very much doubt that you or any of us would be able to put them all in order without knowing which was which in advance. Yes, the cracking this February was unusual (but not completely unprecedented) - one can however argue both ways: potentially the cracking exposed further open water to the ferocious cold of an Arctic winter, allowing more​ ice to form, not less. That's certainly what the PIOMAS model shows, with this year gaining ground on 2012/2011 during the Beaufort breakout event. http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2_CY.png We won't have a good idea what this year's melt will look like for at least another three weeks. Really.

Because the base was expected to last at least another 3 months, until near the end of this year's melting season. It was established in ~September last year on the largest, thickest multi-year ice floe they could find. These should not normally melt out or fragment until September of the following year, if at all. However, they ended up having to use a floe considerably thinner than originally planned, because last year's melt was so extreme that there simply wasn't anything better that they could find to use. To see it breaking up this early in the season, well before the main melt is underway, is a sign that the ice cover as a whole is thinner, more fragile, and more liable to fracture under the normal stresses of an Arctic spring.

Edit: Ignore, link wasn't working for me - is now.

Why? As you explicitly say, you've removed both the (linear portion of the) trend and the seasonality, leaving only the noise. All you can say is that the noise component may or may not be cyclical - assuming there are no nonlinear trend components.

Looking at daily values is daft, there's enough inherent variability in the measurement process that you'll get sharp jumps and apparent slowdowns that have no real physical basis. Yes, the last individual day was a large drop - for the first half of the week things were practically stationary, and one day it even went up. Don't bother looking at anything finer-grain than weekly averages, it's just reading tea-leaves.

I would be wary of claiming a periodic cycle based on little more than a single wavelength's worth of data. Nevertheless, it's possibly a real phenomenon. ... it clearly doesn't, for two reasons. Firstly, since this analysis look at the first differential (i.e. the rate of change), it obscures the net linear trend, which shows up as an offset relative to the zero line. If you rebase it to a zero average (as in your second and third graphs), then you are completely incapable of detecting the overall warming trend!You mustn't forget that are looking at changes in the rate of temperature rise, not changes in temperature. Moreover, even accounting for that, there is still an upward trend in the first diffenential, i.e. temperature rise is accelerating. What you can say is that global temperatures are rising, that the rate of rise is accelerating, but that there is possibly a ~64 year cycle which is nearly wide enough to conceal the acceleration in the level of warming. CO2 has a logarithmic effect on global temperatures, and CO2 levels are rising on a slow exponential, so the net trend is nearly linear. Why do you find this so surprising?