sunny starry skies

Not sure what you're on about, we're talking Arctic here, not the globe. But, to nibble, off topic, which particular regions of the globe have cooled over the past 30 years, and what is the evidence for that? Your second point is rather illogical - if something melts in 2000 years that is present today... and assuming, like Arctic ice, sea ice shelves and small Arctic ice caps... this something of which you speak is sensitive to change (but more stable than a mere snowpatch), then we could say that temperatures between now and 2000 years had not risen above today's levels. What we observe in the real world is that sensitive indicators of change tell us that the Arctic has not been warmer or had less sea ice at any time in the past several thousand years. And unlike the changes during the Holocene, recent Arctic warming is out of step with orbital forcing. It is exactly what was predicted from increasing GHGs, and so is consistent with that theory, but that is not what these observations are about. News from Borge Ousland and the Northern Passage, they are through the last piece of ice blocking their traversing of the Northeast Passage, and will now set their sights on the Northwest Passage. What will they find when they get there? An animation of the Nortwest Passage between day 150 and day 230 (yesterday) shows several interesting things: nwp10.wmv FIrst, you see the remarkably early clearing of ice from the NWP - see the latest NSIDC news for information on that. And later on you see the breakup of ice in the Sverdrup Channel and the other channels linking the NWP with the Arctic Ocean, and the beginning of streaming of ice through these channels to melt in the NWP. Last year, this process barely got started in September before the winter freezeup stopped it. This is yet a further drain on the Arctic's stocks of old multiyear ice, and it may hinder the Northern Passage if these melting floes choke up channels in the Northwest Passage next month. Interesting times...

G-W, I'd actually disagree with you on that point - so far as I can see from the paper, the proxy evidence points strongly towards our being at the levels last seen ~3000 years ago. For example, there are early Holocene raised beaches indicating ice-free conditions a bit further north than present in North Greenland (but ice present beyond that). Add this large body of evidence to the evidence in other papers of glacier ice retreat in the Canadian Arctic exposing of surfaces buried for 3000 years, and the collapse of Arctic ice shelves dated by driftwood to have last been free of fast ice 3000 years ago, and I think there is a consistent picture of an Arctic which is presently at levels not seen for three thousand years. That's still pretty shocking though. It's also worth noting that the Arctic has departed from a trajectory consistent with orbital forcing, and in 150 years has gone from its greatest Holocene extent to the current restricted extent. And of course we're also very clearly on a trajectory with Arctic ice, so other milestones may be reached and passed in the near future.

A very interesting paper (one for 'new research'?) summarising Arctic sea ice variations on long-term, Holocene and recent timescales: http://www.cgd.ucar....eaiceArctic.pdf Polyak, Alley, Andrews et al (2010): History of sea ice in the Arctic. Quaternary Science Reviews. We even get full-text free access from UCAR)! It's a monster review of the state of sea ice over many timescales, and involves many important people in Arctic palaeoclimate research. The quote from the clonclusion may be most relevant to our discussions here, and they have lots of data to back this conclusion up: "On suborbital time scales, ice distributions varied in the Holo- cene, but no evidence exists for large, pan-Arctic fluctuations. Historical records indicate that Arctic sea-ice extent has been declining since the late 19th century. Although this decline was accompanied by multidecadal oscillations, the accelerated ice loss during the last several decades lead to conditions not documented in at least the last few thousand years. Taking together the magnitude, wide geographic distribution, and abruptness of this ice loss, it appears to be anomalous in comparison with climatic and hydrographic variability observed on submillennial time scales and longer-term insolation changes." Maybe this will end the use of single cherry-selected submarine photos as evidence of Arctic ice retreat being 'normal'? Surely deniers can do better than that!

The Southern Ocean does not appear to be cooling according to the dataset you've provided? See images below: Had/Reyn_v2 sst - 1970-1979 Had/Reyn_v2 sst - 2000-2009 Depending on how close to the sea ice edge you you there is either relatively little change or there is warming in the Southern Ocean. Assuming there is little or no change in ocean temperature outside the sea ice area (a reasonable assumption from this dataset, though at odds with other papers on the subject), then it's straightforward to see that the processes of increased wind shear and snowfall drive a sea ice increase. The same processes are not operating in the Northern Hemisphere, where there is a clearly warming ocean and not the same scope for wind-shear, and, I suspect, any increase in precipitation. Jethro - even if the global sea ice extents remain constant due to some kind of see-saw (I don't think this is operating, and I suspect it's more to do with the ozone hole and circulation changes), you can see from the above maps that every basin has seen sea surface temperature rise except for perhaps the Southern Ocean. I think the global sea ice extent 'see-saw' is an illusion that makes some gullible people think everything is OK. Best estimate of September Arctic minimum is now somewhere between 2008 and 2009 based on the past 7 years of IJIS extent loss data from this date. I'd still plump for closer to 2008 than 2009, ie an extent below 5 million sq km, especially if the average of the past couple of weeks is maintained for a little longer, and based on the fact that in recent years we have seen relatively larger extent losses at the end of the melt season. I don't know who was expecting 100,000km/day declines? I wasn't, not in late August!

VP - maybe I didn't make the point clear (though I should've realised someone would jump on it)... absolute gains/losses are comparable in magnitude, percentage gains/losses are very different in magnitude. I (of course agree with you in terms of global albedo). The consequence of a large percentage loss is in the trend, which if continued will see most of the north polar sea ice cap disappear very soon (rapid percentage loss). Northern Hemisphere weather systems are not going to care very much if the Antarctic is reflecting more incoming radiation, even if increases balanced losses in the North. Nor is the Arctic ocean, which will warm further without an ice cover. And as we know, the Southern Ocean is warming, so the best estimates, including the recent PNAS paper, suggest that the Antarctic increasing trend will reverse sometime over coming years/decades despite it's increased albedo just now.

Have you kept up to date on the Norwegians, including explorer Borge Ousland, sailing the trimaran "Northern Passage", in their attempt to be the first to sail both the Northeast passage (north of Russia) and the Northwest Passage in a single season? http://www.ousland.n...n-passage-2010/ This comment on the expedition update on the 15th struck me as noteworthy: "Today is 15 August. We have passed Cape Chelyuskin this Sunday morning, with a good sailing wind, and we ascertain: There is no ice at this critical cape, which so many have tried to sail around before us. However, we are well aware that there is a thick ice belt a little farther to the east of our present position, and we need to make our way through. That should be exciting, and we shall see how it goes.It’s strange to think that Roald Amundsen, on his journey with the SS “Maud†in 1914, required two winters to get around this same Cape. Conditions certainly have changed dramatically since then." It took Ousland less than two months. They are now reaching a crucial point as there is one narrow belt of ice between them and open water to the Bering Strait - they are in that belt now, so will be interesting monitoring them. Those who think Antarctic air and water temperatures are cooling should read this article: Zhang, 2007: Increasing Antarctic Sea Ice under Warming Atmospheric and Oceanic Conditions http://psc.apl.washi..._20-11-2515.pdf If they think Southern Ocean air or water temperatures are cooling can they provide data that demonstrates this and show why the above paper is wrong? This PNAS paper - the one G-W has just helpfully pointed out about the apparent paradox of Antarctic sea ice - also highlights enhanced warming of the Southern Ocean http://www.pnas.org/...8/09/1003336107 EDIT: Stewfox, it's down to the Arctic and Antarctic being different systems of sea ice. The 'extra snow' that falls on Antarctic ice is doing so between about 60 and 75 degrees south. Most Arctic ice is north of 75 degrees north, and in a different system, presumably without a precipitation increase. As for the volume - remember that Arctic ice has lost a much greater percentage of its area than Antarctic has gained, though in terms of absolute areas and 'shiny parts of the world' they are similar.

Nice image G-W! NSIDC update has interesting info on the NWP, including a useful graph showing just how early it began to open this year: http://nsidc.org/arcticseaicenews/ Interesting essay on sea ice formation for beginners here, and some nice images: http://www.arctic.no...ay_wadhams.html Yet again worth pointing out to those like CJWRC that are determined to make the link of below average temps >80N = poor melt season - the energy is going into melting ice, not raising temperatures, therefore the temperatures over the sea ice are irrelevant except to show that melting of ice is happening! Current ice extent: After consecutive 70k+ losses, 2010 is still the 2nd lowest extent on record at IJIS. 2010 is keeping pace with 2008 and has not slowed down at all in melt rate yet. http://www.ijis.iarc...aice_extent.htm On the NORSEX graph, 2010 is in 3rd place, also tracking 2008, but is just above the 2008 value, but well below 2009. http://arctic-roos.o...mi1_ice_ext.png The DMI graph, which some on here have taken as their 'gold standard' I think only because recently it showed the greatest 2010 extent, has 2010 in 4th place, but now clearly in a group with 2009 and 2008, well below all years except 2007. Loss has recently accelerated in the DMI graph, will be interesting to see what happens over the next few days. http://ocean.dmi.dk/...icecover.uk.php The University of Bremen graph looks very like the IJIS graph, with 2010 almost indistinguishable from 2008 in a tied 2nd lowest extent. http://www.iup.uni-b...r/ice_ext_n.png NSIDC's graph, as of 16th August in the link above has 2010 in [EDIT] 3rd place, only just above 2008, but having reduced its extent loss rate recently after a spell of near-2007 extent. No cherries, just data. Five extent measures, [EDIT] two have 2010 in 2nd place, two in 3rd place, one in 4th place. Guess which one has been the favourite of those suggesting everything's ok?! sss Hi noggin - it moves around lots, due largely to surface winds and a little to ocean circulation - check out timelapses, e.g. at Cryosphere Today. A large mass of the sea ice used to be more-or-less anchored onto the north of Greenland and the Canadian Archipelago, maintaining ice shelves that had lasted thousands of years. The Ward Hunt ice shelf, which was lost in 2003, was over 3000 years old, dated by radiocarbon of driftwood, which would suggest that the Arctic was last this warm several millennia ago. http://earthobservat...ew.php?id=23730

Hi stewfox - you could start with the lower part of this post at Skeptical Science. It links to several research papers on the topic: http://www.skeptical...gaining-ice.htm I don't think there's much info on Antarctic sea ice volume - that will be very interesting indeed to determine from Cryosat data, though we'll have to wait a few years for a trend. Extent in Antarctica is increasing (higher maxima, but similar minima each year), but is the volume of ice increasing, stable or even decreasing? My guess is that the processes alluded to in the above Skeptical Science post are capable of creating more thin new ice, but that this pretty much all melts out in the summer, ans so volumes at the end of the austral summer may not be increasing. Clearly it's a good thing at present if there's a decent-sized (area) shiny bit at the bottom of the world to reduce warming feedbacks at present, but how long will this good fortune last in the face of sustained Southern Ocean warming? EDIT: mullender83 - my take on that one would be a 'yes' at least in the short term if the Arctic is less able to hold in its cold air over the winter as a result of sea ice loss. In the coming few winters it will be interesting indeed to see if events even a little similar to 2009-2010 are repeated.

I suppose without separate threads, maybe we could have a regularly repeating post that states: "Antarctica is a completely different place to the Arctic, one is an icy continent surrounded by ocean and sea ice, the other is a sea ice-covered ocean nearly surrounded by largely ice-free land. They are different places, with different processes operating." We could also link to the relevant posts that have been repeated several times indicating that, despite the Southern Ocean's water temperature rising at faster than the global ocean rate, sea ice extent is increasing as a result of reasonable (and in some cases predicted I think) processes, some relating to wind/polynyas and the position of the southern polar weather systems, others relating to snowfall, others still to the ozone hole. All these processes cannot operate on Northern Hemisphere sea ice, as the ice is at different latitudes, and the landmasses result in a different configuration of weather systems. Similarly, the processes driving loss of ice in the Arctic cannot operate on the completely different sea ice system in the Southern Ocean. And most importantly for us in the UK - we're going to be directly affected by Arctic sea ice loss a great deal more than Antarctic sea ice gain/loss. If displacement of polar cold air becomes easier in a hemisphere with less ice, especially in the autumn, we'll notice changes sooner than many.

Hardly "spluttering", but ignoring that insult - how about you take the time to comprehend the gulf that exists between the views of >97% of climate scientists (as reflected in published literature), and the reporting of climate science in the media, which has been biased in favour of "false balance" for most of the past year on the back of the unfounded allegations arising from the stolen emails. The result is confusion in the eyes of the public, a confusion that does not exist in the professional science community. Media stories tend to have been something like "climate scientists say X, but other people [almost universally not publishing climate scientists] say Y, which is the opposite of X". Never mind that all the different Y's are generally mutually inconsistent, the message to the general public is that there is a scientific debate about the very existence of AGW, which there isn't. There is a blog debate, but that is very different from a scientific one. The media seem to confuse bloggers, weathermen and political advocacy groups with professional climate scientists, and the consequence has been at best confused reporting, and at worst outright disinformation. But in the past few weeks there have been a few stories, no doubt brought on by the remarkable weather events of the summer, which are acknowledging the science without resorting to the non-story of stolen emails or the disinformation of a Peiser or a Watts. That, in my opinion, represents a large improvement from parts of the media. Now the weather/climate issue is still a tricky area, but the message has to be clear that these remarkable weather events are more likely with AGW - you load the dice and reduce the odds of these extremes happening. Of course the media has the memory of a goldfish, and we'll have the same issues arise the next time an inch of snow falls on London...

The New York Times put this story on the front page on the 14th - "In Weather Chaos, a Case for Global Warming" http://www.nytimes.com/2010/08/15/science/earth/15climate.html Discussed here - but very unusual for a major newspaper to make that link, and the NYT has got a few things wrong on AGW in the past too. Signs of a change in the media? Or are the changes now so obvious even the journos are getting it? http://climateprogress.org/2010/08/15/new-york-times-front-page-story-in-weather-chaos-a-case-for-global-warming/

Oh I'm sure you could find spots in the satellite image where the ice looks like that... but blue bits don't have any appreciable ice left. You're not seriously going to suggest that the 250m resolution satellite images are insufficient to see the sea ice, therefore it must be there? the 250m resolution images are quite enough to see where the sea ice is present and where it is not. "It's too late and too cold already for any further major ice loss" - you mean like in previous years, when we have, on average, 850,000sq km lost between now and the end of the melt season? That is we're still due to lose at least 10% and perhaps as much as 30% of what is left. I wouldn't call it over yet, while we have the second-lowest extent and a 5-day average melt of over 60,000sq km per day (the 5-day average has been over 50,000sqkm/day constantly since mid-July). Best not to get your information from the serial disinformers at WUWT, who have been shown to be wrong on pretty much every single cryosphere-related article they have written in 2010. Especially when you can see it for yourself on MODIS.

Remember the key processes that affect sea ice - melt from warm water, and export by wind into warmer water - both processes are going to continue to be active for the next month or so, and a few snow showers in Svalbard won't prevent melting of sea ice that reaches the waters around Svalbard. Ice is hanging on by its fingernails, and as mentioned above faces its greatest challenge of the year, while already at its second-lowest extent. Interesting views of the Northwest Passage these days. Not only has pretty much all the ice melted out in the channel itself, but the main channels between the NWP and the Arctic Ocean are now all fragmented and beginning to export the remains of the thickest, oldest ice of the Arctic basin through to the NWP, where it will me more susceptible to melting this year or next. These channels are bigger than Nares, can move a lot of ice, and may result in the NWP being blocked once again - by the death-throes of the old Arctic ice. http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r04c02.2010226.terra

hmmm... healthier and healthier pack. Quite how do you come to that conclusion? Nobody *wants* the ice to melt out - quite the opposite. Most ice in the Arctic is lost through melt due to ocean water, and export of ice from cooler places to warmer places (through Fram Strait, Nares Strait). Both these processes continue to operate, and will dominate until around mid-September. Why are we so concerned about Arctic ice, and why is volume the most important factor? Crucially, volume is an absolute measure, while extent can hide all sorts of nasties. NSIDC extent is measured to be cells 25km*25km that are at least 15% covered by ice. What cells satisfy that criterion? A cell 15% covered by fragmented ice debris no more than 0.5m thick - area 93.75km^2, volume just 0.047km^3. A cell 100% covered by ice on average 3m thick - area 625km^2, volume 1.875km^3. The second cell has 40 times as much ice volume as the first. This means that volumes can fall through the floor while extents hold up, if weather conditions allow the ice to spread out. This graph shows absoute September ice volume numbers estimated from the PIOMAS ice anomaly chart, graphed against the NSIDC September sea ice extent, both for 1979-2009. People are used to seeing PIOMAS volumes in the familiar 'anomaly' chart, but that does not tell us when the volumes will reach zero. They will (temporarily) reach zero when the September volume anomaly reaches -13.4 (-13,400km^3). Both graphs show an accelerating decreasing trend. Whn a quadratic fit is put through (in both cases it has a better r^2 value than a linear fit, unsurprisingly), we see September extent declining to zero by 2030, and volume declining to zero as soon as 2017. And 2010's September volume value looks unlikely to be much above 4,000-5,000km^3 (at the July anomaly value it would be just 3,200km^3, or just over half the volume left in 2009). All these estimates put 2010's volume below the quadratic trend, indicating zero September ice volume sooner than 2017. If there's zero September ice volume in 2017, there will be zero September ice extent. PIOMAS is a model (I hear you cry!), but it is validated against a variety of data. Cryosat-2 will check the absolute volume numbers for 2010, and we will be able to see if this prediction is valid. If PIOMAS is wrong, this prediction is wrong. If PIOMAS is right, then extent values are currently fooling us into thinking that the rapid and accelerating decline in Arctic ice is a less rapid and accelerating decline than we thought... The ice is visibly very thin... what happens when the thickness declines to zero, something perhaps quite likely within the decade? sss

In reference to floods, I wasn't considering GCM's - there are a number of issues regarding precipitation there, but the observations of increased occurrences of high river stages. The PDF was indeed a simplified idea, as the PDF itself may expand (expected), contract or skew under higher temperatures. But given a null hypothesis of no change in the PDF, we would expect to see a higher occurrence of remarkable events, in line with the observed increased frequency of other indicators.

VP, I absolutely agree with that point. It's why you don't go to the news reports for your scientific data, and why you need to ensure your data source contains a continuous record and that you have accounted for reasonable factors that may affect the result. For example I wouldn't measure number/impact of hurricanes by insurance claims for that very reason, but I might be happy to measure them by sediment layers in an accumulating basin that is otherwise undisturbed. The records of increasing temperature maxima over minima in the USA is an example of a robust measure of extremes, or the various papers showing increased frequency of different sizes of flood events - these are better measures than the 1/1000 year events, because we can statistically analyse the smaller events. Though at the same time we do expect to see more truly 'extreme' events occur as the PDF envelopes trend upwards. sss

Stewfox - 17 countries have set national high temperature records in 2010, one country set a low record - the 17:1 ratio for this year is perfectly real and has nothing to do with polar bears. Indeed it may be worth waiting until the end of the year, but I don't think the ratio is going to change a great deal, unless a large number of Southern Hemisphere countries have some remarkable cold in the next month or so. Guinea isthe only country to set a national low temperature record in 2010. The US data shows the local temperature record ratio steadily increasing in favour of high temperature records over the last 40 years. These decadal averages are pretty robust. Please don't try and twist the numbers! http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1569 - 17 national high temperature records in 2010. http://www.ucar.edu/news/releases/2009/maxmin.jsp - US maxima outpace minima in recent decades. Ladyofthestorm - 'barbecue summers' refer to now-dumped seasonal weather forecasts which never had much reliability. Climate is entirely different, so best not to use the old strawman. How to separate human from natural - try explaining away these factors: http://www.skepticalscience.com/human-fingerprint-in-global-warming.html Also: http://www.skepticalscience.com/More-evidence-than-you-can-shake-a-hockey-stick-at.html Contrary to what some might have you believe, there's very good evidence that these changes are a direct consequence of our adding CO2 to the atmosphere. Your numbers on the contribution of human CO2 are also incorrect - see: http://www.skepticalscience.com/water-vapor-greenhouse-gas.htm http://www.realclimate.org/index.php/archives/2005/04/water-vapour-feedback-or-forcing/ Water vapour is a feedback, not a forcing - if you instantaneously doubled the water vapour in the atmosphere, it would all rain out in a couple of weeks, so it has no long-term effect. If you double CO2, it's not reabsorbed for centuries, and meanwhile the raised temperature results in more water vapour in the atmosphere, as shown below: http://tamino.wordpress.com/2010/08/08/urban-wet-island/ Which leads us to expect higher temperatures and more extreme precipitation events, and more "disasters"... sss

Stable isotopes! http://www.skepticalscience.com/its-not-us.htm

Weather patterns conspire to make a hot summer for Russia. Why is it hotter than all previous summers, if it's just El Nino or some other cycle? Could it be something to do with all that extra downward longwave radiation we are measuring?

California: is one cherry - What about the other 49 States? Cold records can still be broken, just a lot less frequently than warm ones. Antarctica: various entirely reasonable mechanisms exist for increased Antarctic ice extent in a warmer world, as has been discussed elsewhere (wind stress, ozone, circulation changes etc). Antarctica and the Arctic are rather different systems, in case you hadn't noticed. You could learn something from: http://www.skepticalscience.com/antarctica-gaining-ice.htm and the papers cited within. Surface air temperatures over the Southern Ocean are warming faster than the global ocean rate - were you aware of that? Arctic: is the pick of the bunch... You are aware that it requires energy to melt ice? What is happening during Arctic summer months, and why would that hold the surface temperature close to freezing? What is the state of the Arctic ice, in terms of volume or extent? If it's so cold in the Arctic why are we at the second-lowest extent for this date? So nope, none of your points are inconsistent with an anthropogenically warmed world. sss

Hi G-W - very interesting paper indeed! This article would appear to support what you pointed out last winter and I thought was insightful at the time - that our unusual winter weather pattern (exceptional negative AO etc) was not a challenge to the concept of AGW, but actually a consequence of it, through modification of Arctic weather patterns. As the paper says, there's not enough data to be conclusive about it, but there are good reasons to suggest that some of these weather pattern changes have an anthropogenic cause. To add something else into the mix, there is evidence that solar activity can also be linked to shifts of certain weather patterns - not significantly overall temperature, but to alter the regional preponderance of meridonal vs zonal circulation patterns near the UK during solar minima. There was a paper on that not so long ago, not sure what the ref is. 1995/96 and 1996/97 had good cold episodes, as have the last two winters. I wonder if we see the two factors operating together, or whether the new changes in the Arctic (substantially increased and increasing open water in Septembers since 2002) will swamp the old subtle effects on our circulation. The test for our winters will be if such patterns recur during years of higher solar activity. {Note all this refers to UK weather patterns, not to global temperatures.} I think the past will increasingly be a poor guide to what future weather patterns have in store.

The average melt from the past 7 years in IJIS data to the end of the melt season between 8th and 23rd Sept is 1,219,420sq km. This is enough to take us down to about 5.1m sq km, so I think the 5 million is certainly in play still. A repeat of 2008's extent loss (and there is plenty vulnerable ice visible on MODIS or CT, more than there was in 2008) takes us to 4.6m sq km. The trend in melt rates for this phase of the melt season (10th Aug - variable end date in Sept) is upwards over the past 7 years, and so it's quite plausible the final melt to come in above the mean, and so the final extent to be close to or below 5m sq km. JS - remember this winter didn't break UK cold records, and the Arctic was remarkably warm to compensate for our cold. The globe was also remarkably warm at the same time. sss

Dev's point is perhaps the best way to put it - the events are natural (weather), but not 100% natural, because there's a human element that has nudged the system towards being capable of more extreme events (high temperatures, large precipitation events). This is statistically measurable, and the floods in Pakistan, fires in Russia of remarkable size are consistent with that. Individual events can still be considered chance, but a statistically verifiable rise in high temperature events or large precipitation events as a consequence of our forcing of temperature can be considered direct evidence of our impact on climate.

Yes, I think! As the PDO is based on the spatial distribution of anomalies, and not on the size of the anomalies themselves, then you can still get PDO oscillations of the same magnitude as before, even though the whole basin is warmer (which it is). Take these 3 numbers, a, b and c to represent respectively the western, central and eastern North Pacific in a PDO -ve phase: a=10, b=15, c=7. And take this series in a warmer North Pacific (exaggerated for effect): a=14, b=19, c=11. The relative differences as you traverse the basin from a to c are the same in both cases (5 and 8 ), but the ocean is much warmer in the second instance. The PDO for both cases would, I think, be the same. The absolute temperature of the water, and therefore it's ability to warm the atmosphere or transmit further warming into the deeper ocean is higher in the second instance, but with the same PDO. I don't think it works as a 'milding out' G-W - I think we can still see strongly negative PDO episodes. But they are negative PDO episodes with warmer water on average across the basin because the ocean has in the meantime warmed in line with global temperatures...

Jethro - did you look at some of the links I posted earlier? - that was the point of that earlier post: we don't have to wait for new evidence, as we already have substantial meteorological datasets for many countries round the world. These datasets show the increasing tendency towards warm temperature records over cold ones (in 2010, for national records the ratio is 17:1), and the datasets already cover many decades. There's a similar tendency towards large precipitation events, to be expected if there's more water vapour in the atmosphere. Is there more water vapour in the atmosphere? Here's an interesting post from Tamino on that one (data from NCDC State of the Climate): http://tamino.wordpress.com/2010/08/08/urban-wet-island/ Specific humidity is rising in line with rising temperature, exactly as expected. This not only confirms the temperature rise and the presence of the powerful water vapour positive feedback, it also provides the extra moisture for an increased frequency of extreme precipitation events. Can you directly attribute a single weather event to AGW? Maybe not, but events like those in Russia would be rather less likely without AGW, and are just what was forecast as a consequence of AGW. Every year it is statistically much more likely that hot temperature records will be broken than cold, and this is borne out by the data. Events like those in Russia, Pakistan and elsewhere are entirely consistent with a warming world. Significant snow events in winter are also entirely consistent with a warming world... until the warming in a particular place takes the temperature above freezing. It is intriguing how few cold temperature records were set last winter, yet there were plenty exceptional snowfalls. In what way is this inconsistent with a warming world? What would I consider as events consistent with a cooling world? Worldwide, for high temperature records to be broken less often, and an increased frequency of breaking of low temperature records. A reduction in the intensity of extreme precipitation events, be they of rain or snow. A persistent reduction in global mean temperatures, both in individual months and in the 12-month running mean. A significant increase in the volume of Arctic sea ice. sss