trevw

ahh, had to clear my cache - have now seen it! :-)

saw this in the other thread but can't find the text on the site.. has the confimation been withdrawn from the front page, is it buried in a sub menu I haven't found or am I just blind as a bat? :o thanks Trev

p3, thanks for the clarification, there seems to be little in the way of visible polyna on the satelite images on cryosphere except for the small one on the beaufort sea side of things.. does this mean the two figures are relatively close to being 'in step' this year? Is there anywhere we can find the current figures for ice extent as opposed to area?

so.. what's the current record minimum? was that 2002? looks like we are close to beating last years minimum with 6+ weeks of potential (if usually slow) melt left? Trev

I think there probably are no scientists with even a passing understanding of physics that don't agree that co2 in the atmosphere causes warming - the dissagreements tend to be more along the lines of how much 'more' warming when adding 'more' co2 and whether the effect of increased co2 is significant enough to explain or significantly contribute to current warming trends?

AF, did you ever get an answer? Carinthian, how soon do you expect the change in synoptics to start having an effect? I realise Cryosphere Today is not the be all and end all on Arctic monitoring but the current rate of ice loss looks at odds with talk of final summer ice loss at this point.. especially when melting continued on and off almost into october last year..? Also, the Barent Sea ice area appears to be down on last year not up? with the kara sea area hot only a touch behind last year - or is there a different data source that shows the opposite? Trev

isn't that the link between CO2 and temperature without feedbacks included? the effect of CO2 is bound to reach a saturation point when there is no more radiation at the right frequency to absorb/scatter? I thought that the issue was that the 'forcing' caused by CO2 was relatively small but that it still changes the temperature minutely upwards, this causes water vapour levels to rise until a new equilibrium is reached and then it is the water vapour that causes the majority of the actual warming even though it is just a feedback mechanism.. thus a few tenths of a degree aren't trivial? Also a great deal of the 'trapped' heat energy would surely get absorbed by the seas and pulled into the deep ocean circulation causing a delay in its effect on the climate.. so the temperature rise we are seeng now is being caused by the rises in the early half of the next century? again my take on this would be (with a pro AGW hat on) that CO2 as a forcing is not massive and if the climate were not in a state where feedbacks were poised to kick in then maxing out CO2 would potentially just slightly mitigate the coldness of the climate. Also, in this instance the presence of high levels of CO2 is presumeably just a feedback mechansim (unless caused by something 'external' to the climate itself such as super volcanoes or methane hydrates etc) agreed, humans seem hard-wired to try and pick/test data to re-inforce their held opinions rather than try to disprove them, this 'syndrome' has a name (which escapes me at the moment). However on the model changes in question, I was under the impression that such cooling could not be achieved from the models without compromising their ability to predict the climate over the past century or so.. which is obviously a bit of a stumbling block. Trev (couldn't quote the quotes from your post, not sure why)

seems like we agree mostly then on the uncertainty of the severity of the current situation but lean towards the opposite ends of the range when it comes to our 'beliefs'.

I think you are hanging a little too much on a misnomer that originated from a need to explain the process of the absorbtion of longwave radiation by carbon dioxide in a way that the general public could understand from a 10 second news spot. That CO2 absorbs and re-emits radiation across a certain range of EM radiation frequencies is as sure a fact as that the sun will rise tomorrow - actually surer as the sun could always explode through some hitherto undiscovered process. This doesn't mean that the result is simple, various feedbacks could obscure or massively multiply the effect and this is where I (personally) believe any doubt still lies. I tend to the view that there will be an initial re-inforcing of the warming effect due to a compensating increase in water vapour and albedo changes (currently IMHO being seen) followed by a plateau beyond which additional CO2 has little extra effect - at what concentration that would kick in I have no idea. However I am open to the possibility that some Natural cycle is responsible for a proportion (possibly a large one) of the current warming but even if this is the case the CO2 absolutely 'has' to be making things worse - just maybe only by a little bit.. Trev

I generally believe from the evidence that AGW is a real effect that will probably have an ever growing effect on our world, my only doubt lies in what proportion of the currently observed warming is down to us, as such I would like to see any articles from sceptical scientists that point out real issues with the idea that it's all down to CO2 - unfortunately things like the below smack of desperation and can surely only have been put together by someone who was knowingly trying to misrepresent facts to generate a false impression? http://www.realclimate.org/index.php/archi...ation-lesson-2/ given the importance of the issue I find this kind of thing quite disturbing.. Trev

would have to agree. Also, although cryoshperes figures aren't the whole story, my recollection (which could be wrong) of last years melt was that it was constantly ahead of the previous year (2005) until quite late in the season so even though we are at a better place than this time last year by a nose might we still be worse off than at the same time in 2005 - in which case a new record low ice extent is still within possibility for the year. Trev

am confused, I read this from a link on the NSIDC site: http://www.adn.com/life/story/8881213p-8781543c.html sounds more like a comment from last year? but it is definitely dated 2007 - have I missed something, cryosphere seems to have shown the area as greater than last year from the start I thought... or is this a difference between area and extent.. :unsure:

thought this was an interesting article - is about the grounding point and what it might take to float the ice off its grounding point.. http://earthobservatory.nasa.gov/Newsroom/...7030124445.html Trev

I'm not against nuclear and think that for some countries it should definitely be looked at as part of the solution, but I read something the other day that explained that the US could provide all their current electricity demand and support their current rate of increase for a number of years using _just_ geothermal energy - cheaper to build than nuclear, using known technology and zero CO2 emission... seems a no brainer to me..

P3 and G-W, thanks for all the links - am starting to work through them now! cheers Trev

GW, very interesting discussion/info, out of interest, what is your source of images? do you use the nsidc site? they seem about a month behind, I was wondering if there was somewhere that had more up to date images.. cheers Trev

I take it given the sst chart that was posted the other day that either cryosphere today has blown a fuse or someone is out there doing nuclear testing on the sea ice or something? Trev

Hi Penguin, surely lots of accepted science though deals in probabilities? Also things like newtons laws of motion etc. are just approximations and so therefore not 'right'. Many physicists expected the standard model to be proven incomplete (wrong) at some point but it is still science. Quite often todays science is just a best fit to the evidence. Isn't that why science is littered with the word 'theory'? (And the toehold that fans of ID use). No matter how often something happens one way it doesn't prove it won't happen a different way the next, just that given the evidence so far it is the best fit to our understanding of the way things occur? I believe that the way particle interactions are determined is exactly a 'collection of endless perhapses' the probabilites are then related to how many different ways each outcome can occur. My guess is that the guys on realclimate, while accepting that there is a lot of uncertainty in some areas, might get quite exasperated with people questioning things that have been proven 'right' beyond a reasonable doubt. (like increased CO2 causes a 'warming effect') This could well influence their tone I suppose? Although I must admit I've not noticed issues with their tone, however my leanings are towards AGW being real and an issue. My feeling is that there are a number of core areas where the science has progressed to the point where the conclusions can be regarded as fact. However for me it is the manner in which these will interact with each other and any as yet unknown factors that cause the uncertainty in how our climate will respond. cheers Trev

Hi, for me the reasons I haven't ditched the car and moved into a log cabin at the end of the garden come down to two: 1) is that it isn't really possible given the current setup of society. My company won't let me work from home. My government won't give me any tax breaks for having an environmentally friendly home. Comuting by train is almost impossible given the journey. To afford childcare/a house/reasonable standard of living etc. I need to keep my current job... you get caught in a bit of a trap. 2) being an 'early adopter' of 'strong' green behaviour puts you at a severe disadvantage (cost/time etc. as above) so why be one of the ones to do it first? especially given the feeling that the problem is so large 'what can one persons contribution do?' let the really keen people blaze the trail and join in when it is not so painful.. oh, and laziness trevw

Hi PM3, thanks, though I wouldn't say 'studying' more 'keeping half an eye on' :o as I feel it is one of the most interesting indicators of the extent of any climate change around. I haven't really got into the weather/predictive side of it before at all, definitely find it all fascinating tho and will contribute if I have anything of interest.. also, didn't realise this thread was here.. up until now I've been lurking around the environment change area and occasionally joining in.. and of course avidly following the yearly 'will it snow' rollercoaster on the extent vs cover question, I wonder how accurately they are using the terms? Various places seem to use phrases like 'extent of cover' - and while cryosphere today talk of 'cover' a quick browse doesn't show up any definition of what they mean by the term as far as I can find.. do they mean area with 100% sea ice coverage? Presumeably the analysis works on some kind of grid system so there must be some form of threshold? Trevw

thanks for all the info, have been following cryosphere today and various other places for a couple of years now so is interesting to see all the other sources of information and read all the discussion.. in case you've not seen it, nsidc have started up a special news page for last few weeks of the summer melt season.. http://nsidc.org/news/press/2006_seaicemin...seaicenews.html looking forward to more informative posts over the turn of the season trevw

isn't the problem that it just looks like that most of the time because the climate sytems show hysteresis? Things move steadily with negative feedbacks limiting the speed of change until a threshold is reached.. after that change accelerates and even if the driver is removed the climate doesn't return to its original state.. (link for relates to the THC but probably applies to many other climate systems.. arctic sea ice perhaps?) http://newton.nap.edu/books/0309074347/htm...053949960093001

thanks, that's very interesting! in the posts below the realclimate article there is a discussion of the source for the topic article... sounds like the conclusion is that our climate would be very much like that of british columbia but a trifle warmer rather than anything like labrador etc. and that the greatest heating effect caused by the TH circulation is further north. Will quote the two (Edit: make that 3) bits below.. (hope it's not too long) Trevw

out of interest from what I've read, the media perception that an ice age was on the way in the 70s was generated by a misquote of a scientific paper that said something along the lines of 'an ice age is iminent in the next 20 to 30 thousand years' predictably the geological timescales were dropped when reporting the paper and other people just quoted the original article. If the internet had existed the paper might have been available online and the public (or at least the interested browsing public) might have been better informed. Doesn't change the point tho this weeks crackpots are next years visionaries - trouble is picking the right crackpots trevw

would it actually grow.. or given global increases in temperature would it just stabilize around the current levels and stop shrinking? Read somewhere that by the time the warmer water has reached the poles it has lost most of it's heat so am not sure how much difference it would make to ice formation.. (would be really interested to know) Presumably if the ice did grow this would be a fairly slow process - steady build up of multi-year ice over decades giving a better base for each subsequent winters freeze?