trevw

nsidc have finally updated their ice area graph and it shows extent converging with last years levels.. http://nsidc.org/arcticseaicenews

Welcome to the endless circular debate! I would have guessed you went for 3 from the way you phrased the options, an alternative would be: 1) The ones who are so far in denial that they cant accept other options apart from the one they blindly follow... 2) The ones who just want to "lets see" how it all pans out whatever the consequence and ... 3) the ones who in general accept the majority of mainstream science and are concerned enough to think it worth some level of action on which scale I would put myself somewhere between 2 and 3 as well I think if we ditch both of our 1)s we end up with a more balance view of the 3 positions In my experience those that attempt to counter the AGW theory are generally the ones that have been edited - however this is a subjective impression. It would be interesting to some statistics - graphs of graph tampering, as if we don't have enough graphs eh? To prove the point on graphs debunking graphs.. and another example of where the pro AGW one has more info (spot the indication of 2004 temps) http://upload.wikimedia.org/wikipedia/comm..._Variations.png But to use a perhaps slightly dubious metaphore, a person doesn't have to wait until they have liver failure before being concerned that they might 'on evidence' be drinking too much.. (On the flip side lying in bed all night worrying about it to the exclusion of all else but not doing anything then getting run over by a bus because they weren't watching where they were going is a little on the pointless side too) Trevw

Am not saying that there is nothing interesting going on but I don't think anyone was saying that CO2 effects would flatten out natural variation, only be superimposed upon it.. that would mean that what would have been a drop in temps without CO2 forcing becomes a shallower drop/plateau/slowing of warming in addition I'm fairly sure there is quite a lag built in. Unfortunately due to the long timescales of the experiment we are forced to analyse and re-analyse datasets for the same timescales repeatedly - this could be a brief hiatus caused by variation or the start of proof that Natural variation in the near future will totally override CO2 forcings.. We'll all know the answer in a decade or so I suppose. it would be interesting to know the net mass of ice loss over those 10 years (and I do think it would be a loss) and try and work out how much energy this would have absorbed and see if it is large enough to register against some kind of 'total global climate system energy level' or whether it is a mere drop in the ocean (so to speak - apologies). The energy has got to come from somewhere - presumably the oceans.. This would have to have a cooling effect which could then oscillate with the ocean circulations.

when seen in context (the graph above is the last few entries on this one expanded : http://www.metoffice.gov.uk/research/hadle.../HadCRUGNS.html) the trend over the last few years looks very much like the short term plateaus/dips that have occurred every five years or so for the last 50... On another point these are just near surface temps.. presumeably a large amount of the earths 'energy' is tied up in the oceans, a lot of which is not near the surface hence if there are decadal scale deep overturning currents presumeably the pattern that these add to the surface temps would be a fluctuating one? This would then interfere with other natural variations, sometimes constructively sometimes destructively - perhaps resulting in a curve similar to the one shown while allowing for a steadily increasing 'total energy budget'.

CT seems to have recovered from its blip and be showing more credible data again.. not much in it now between this year and last. I guess the interesting thing will be watching the arctic basin graph in particular?

am pretty sure that as you point out there was an issue with some of the data processing of the original mann graph and that this fact has not been contested, but when redone correctly with this issue resolved there was no appreciable change to the shape of the graph.. There have been other reworkings that use invalid statistical methods to radically change the results and these rely on the fact of the minor error to try and establish themselves as credible alternatives - which they are not.. Trev

Entertainingly written, but could it just be that the reason the AGW 'cult' can always find an explanation for climate behaviour, that at first glance does not appear to fit in with their hypothesis, is that the hypothesis is correct and therefore there has to be an explanation that allows it to fit in with the hypothesis? just a thought, it just seems that to detractors these explanations would naturally seem 'overly convenient' but if for just a second you posit that the hypothesis is by and large correct then they are inevitable. Maybe humans are largely at fault... Edit - more on topic it looks like the CT data, at least for the arctic in Baffin and Bering is getting back to where one might expect it to be. I would expect them to smooth out that blip in the next couple of weeks?

my comment was more to do with our civilizations extreme sensitivity to changes in key locations in the short term rather than medium to long term issues.. longer term without some form of action to slow change obviously things get even more 'tricky'

do you have a source for that? I have never heard anyone claim that CO2 levels were higher within the last 200 years before...

fair enough..:-) must admit though that most of the climate scientists I have seen cover the subject generally rubbish the idea of true runaway global warming, as far as I know it is only the press that like to start spouting the old venus stuff.. I think the issues are going to be with the change of climate in areas that we are currently reliant on conditions remaining stable.. sea rise in low lying areas, drought in grain belts and rain forests... If we were free to all up sticks and move to new areas best suited for food production and city placement then global warming may well not be such an issue - unfortunately we are not.. (without massive economic and political upheaval)

I don't doubt the ice is reducing and that may be an accurate representation but CT often has glitches and on trying to view the 30 day animation it gets stuck towards the end... could there be data issues?

not to be picky, but who has? you are talking between 251 and 65 million years ago.. dinosarus roamed the land etc. Our current civilization is extremely complex, the supply chains for those of us in the so called 'developed world' are long and thin.. It wouldn't take much of an upset to strain our civilization to its breaking point... Of course 'life' will survive. With a radically reduced human population I imagine many species would thrive no matter what state the climate settles in to, I also think it is hard to imagine repercussions of AGW that would prevent humanity from continuing to exist - we are pretty adaptable after all.. But our civilization? Pretty easy to nudge into a spiral I would have thought, that is more my concern. (I would agree though that a significant cooling would be just as concerning - probably more so but is not as far as I know currently on the cards. )

would have said you are talking about differing aspects of sun 'strength' one the actual output levels of the sun, the other the percentage of the suns output reaching the surface/lower atmosphere.. maybe your opposing trends will cancel out.. :-)

there is some doubt about that - can't find the original source but it is summarised here http://www.independent.co.uk/environment/f...ins-597214.html so it sounds like we just need to bulldoze the rockies and we'll have winter weather in abundance... :-)

wierd things going on on the CT site.. are they perhaps reversing the change that occurred earlier in the year when their tale of the tape graph and northern hemisphere anomoly graph plunged south by a considerable amount?

I'm afraid that since bellamys false claim that 555 of 625 monitored glaciers were growing when this blatantly wasn't supported by the facts (I think in the end it was discovered he misread a paper and it was 55 of 625 or something?) has rather dented my unwavering belief in what he says.. to read him flogging the old 'scientists said we were going into an ice age in the 70s' horse is also dissapointing. In addition I believe the hockey stick graph was left out from the IPCC, not because it has been proven incorrect, but because it was seen as too 'contriversial' (many re-analyses of the same data have confirmed the shape of the original graph even once any critisisms are catered for) the comment that the hadley centre found the world hasn't warmed since 1998 is 'true' but disingenuous, why does he pick 1998 you might ask? http://www.metoffice.gov.uk/research/hadle...a/HadCRUT3.html because it was a largeish peak in world average temps that hasn't yet been exceeded.. one would expect year on year variation and it 'could' possibly be that temps have now peaked and if so we will know in time but the trend on this graph is definitely upwards imho.. he berates those who believe the evidence for AGW as not trading in facts and then seems to misrepresent the evidence.. it seems a shame as he has been a scientist I grew up watching on TV and I would imagine there must be good reasons for him not to believe in the case for AGW and it would be good to know them but it is buried in rhetoric. Trevw

have found the link... fresh water of a certain mass has more volume than the same mass of salty water, I agree that volume increases for both with temperature, however I am not certain at what temperature difference the effects would cancel out.. also, I imagine the actual difference in temp between the sea water (just above zero?) and the melt water at zero degrees is insufficient? anyway, here's a quote: and here's a link: http://www.physorg.com/news5619.html I guess though if there was an effect at the moment it would be cancelled by the fact that as sea ice melts in the north it grows in the south and vice versa.. and really melting of land based ice is far more concerning, I just thought it an interesting point.. trev

just as a point of interest, there was some research that claimed that while the above is 'mainly' true there is a 'second order' type effect that would incresse sea levels with melting of sea ice.... something to do with the difference in density of salty and fresh water and the fact that sea ice has a lower salinity content than the sea water.. the effect was fairly small though if I remember rightly, reported on the nsidc site some time ago. trev

have you watched the high res animation on the CT site? cannot download anything that big at work myself.. worth a gander?

so much for my guess of 3.2 and 4.9, the numbers are currently tracking at 3.22/4.92! with weeks of potential melt to go.. are we looking at the first sub 4 million Kmsq area year also being the first sub 3 million Kmsq year? Also interesting to note NSIDCs comments on the 'state' of the ice in various places being a mass of broken ice floes with melt ponds (all of which plus the water between being included in their 4.92 figure)

am very interested to see the next report from the NSIDC. The graph on Cryosphere Today seems to still be intent on hitting the floor, from the way its going a sub 3 million square miles finish looks likely? Do we think this is really representitive or could they be having problems with their data? it looks like they've had to add an extra 0.5 below the line on the anomaly graph for the basin and will shortly have to add another! :o Trev

P3 I'll have a bash :-) 4.9 extent 3.2 area Trev

I'd have thought (which doesn't make it the case) they were each better for different things, i.e. perhaps that extent is more relevant to the refreeze - presumeably once the air/water temps dip then open water between ice floes (included in extent) quickly refreezes? Whereas area is more relevant to how close we are getting to 'ice free' in the arctic summer? Trev

sleet, as I understand it the higher number is extent, the lower is area (extent minus the holes) record min extent = 5.36 ( we were at 5.4ish on the 14th not sure what we are at now) record min area = 4.01 current as above.. area seems to me the more 'interesting' measure, it would be great to see graphs of both plotted against each other over time. Anyone got any thoughts and where this is going to end? seems like we lost 0.4 (area) in 7 days from 9-16th, surely it must slow down soon! low 3s? find part of me willing it to pull up and the other half hoping that the melting will continue to the point where it can't be ignored by anyone.. Trev

realclimate have just added a new item about it too - doesn't expand on cryosphere much though http://www.realclimate.org/