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  1. Thanks for that lucid posting Prof Mekik.

    This leaves me once again pondering the wider implications of this years Arctic ice melt. The polar region will still be dark and very cold in the winter. But thinner ice means more heat flux between atmosphere and ocean and more water vapour. So it probably won’t be as cold as previous decades.

    Anyone know if the vertical temperature difference between surface and stratosphere has a role in forcing the AO into a +ve regime?

    Will this years Arctic events force a tendency back to -ve/neutral or reinforce the recent +ve tendency?

    Comment by Cobblyworlds — 22 Oct 2007 @ 6:20 AM

  2. Things are not as simple in the Mediterranean. Last spring was one of the more rainiest of the last 50 years in most of the Iberian Peninsula (western Mediterranean), and last summmer one of the less warmest. Furthermore, it is not unusual that seasonal or annual climate anomalies were of different sign in parts of eastern and western Mediterranean.

    Comment by Manuel — 22 Oct 2007 @ 6:23 AM

  3. I just noticed something, so please pardon any misunderstanding.

    AGW in the climate science world refers to ‘Anthropogenic Global Warming’. In other areas, it seems to sometimes represent ‘Anti Global Warming’, as in those that refute the scientific consensus in favor of singular or narrowly scoped views.

    So in case if there are any others that might be confused by what AGW means, take it in context because there are lots of acronyms in the world.

    On the likelihood of prolonged NAO, it just seems logical that if you heat up the planet, the middle will still be hotter that the top and bottom (so history has evidenced). So anything in between the Tropics will be subjected to higher dangerous temperatures in the sense that water and food will continue to be constrained resources.

    The rest of the world will be affected also of course. The head in the sand thing, and BAU will be the norm until leaders wake up in force. That just means it will be a more expensive problem as fixing later will cost more than fixing now. Caught in the middle of this are a lot of people that will suffer the fate of decisions made by people that are continuing to ignore reality and common sense. It is unfortunate that many will have to pay a higher price for the decisions of a few.

    Comment by John P. Reisman — 22 Oct 2007 @ 6:48 AM

  4. Thank you, Figen Mekik. You make vivid the interrelations of planetary processes. The natural thought processes of North American habitants indicate to me a positive forcing still. Or perhaps I am using precise words illegitimately. Oceanic inertia may leave inundation to later in the century, but the winds which have whipped around the Greenland ice cap in certain given directions with certain given forces are likely changing now with even the meagerest shrinkage of the cap. Of more imminent concern is the absolute believing of Southwesterners that they will treble their growth in the next two or three decades. I have tried mitigation with a friend located there. “Oh, I wouldn’t worry. We’re already planning desalinization plants on the Pacific to bargain for water rights.” I think I’d have better luck going to Greenland to wave the winds back into their “proper” places.

    Comment by Juola (Joe) A. Haga — 22 Oct 2007 @ 6:53 AM

  5. The situation for the people of Turkey sounds pretty dire – even compared to drought stricken Australia. If the current droughts are truly the result of AGW, then should we interpret this as evidence that the “reduce emissions and eventually stabilize” plans are insufficient and we need some sort of geoengineering to undo the damage we have done?


    @1 – Does anyone have any idea/predictions whether the ice refreeze in the winter will lead to a lower ice mass during winter?


    Comment by Joe Andersen — 22 Oct 2007 @ 7:05 AM

  6. AGW … AGW ??? ahhhh!! Anthropogenic Global Warming … intuitively obvious eh? silly me, very very clear exactly what it means too eh? ‘anthropogenic’ being a word that I use EVERY day


    [Response: Actually it is a word we use everyday, and sometimes we forget that others don’t. A simple request is usually sufficient to clear up any misunderstanding. – gavin]

    Comment by David Wilson — 22 Oct 2007 @ 7:41 AM

  7. I’d like to know which standardization scheme was used in the tree-ring record.

    Can you please post a reference to the treering precipitation record.

    Comment by Aslak Grinsted — 22 Oct 2007 @ 7:46 AM

  8. Drought conditions seem to becomming very widespread, and areas of flooding becomming smaller in extent (even though they are severe when they do occur.)

    Repeating a comment that I made on this site a few months ago:
    My conjecture is that as the atmosphere is heating faster than the oceans, that worldwide, the average relative humidity is the decline. The analogy is a bathroom… in order the get a bathroom less “steamy” (without getting rid of the water) is to heat the room (not the water). I assumed this is the reason that the tendency to drought is becomming widespread.

    There was no response to my comment last time, hence the repeated post.

    Comment by Lawrence McLean — 22 Oct 2007 @ 7:55 AM

  9. Not sure if it helps much, but my understanding from the UK Met Office is that the NAO is broadly neutral or trending negative at the moment – see their chart and explanation on their website:

    This implies a winter in the UK and NW Europe that will be a bit cooler than those experienced in recent years, with perhaps some more rain for the Med. region. With that in mind, it looks as if there’s a subtropical-like storm developing in the western Med at the moment. These aren’t unheard of, but they are unusual. Watch out for news of how this storm develops later this week.

    Regarding Arctic ice, has anyone given thought to the submarine ice off the coast of Canada, and presumably Russia/on the other side, and how this is likely to react/behave as the Arctic warms up? This is relict ice from the last glaciation that has been buried under debris and later submerged as sea levels rose. There’s loads of it, too – many metres thick, over large areas of the sea bed Strikes me as another highly non-linear facet of the system, which could make the local climate response to AGW even more chaotic or confused.

    Comment by Nick O. — 22 Oct 2007 @ 8:53 AM

  10. Thanks Gavin, and David I fully understand your point. I’m just gaging by the fact that you have 4.3 million visits on this web site, and guessing that probably not all of those visits are from scientists. I can only speak for one of your visitors :) and I know I’m not a scientist.

    Comment by John P. Reisman — 22 Oct 2007 @ 9:00 AM

  11. @8 Lawrence:

    Actually the humidity is predicted to go up, and it has recently been reported that it is indeed going up around the globe. In fact this is one of the main features of (excuse the acronym) AGW — raising the temperature a little causes more water to be held in the air, and since water vapor is a potent greenhouse gas, it raises the temperature still more. By itself, carbon dioxide etc. would not have nearly as big an effect.

    Unfortunately simple reasoning by analogy doesn’t work for such a complicated system. The reason for more droughts is partly because the location of precipitation gets changed, with some dry areas tending to get drier while some wet areas tend to get wetter (with more flooding); and second, warmer days and especially warmer nights lead to more evaporation, drying out the soil… while adding to the humidity.

    Comment by Spencer Weart — 22 Oct 2007 @ 9:02 AM

  12. First, I’d like to acknowledge the very patient and constructive support I received from William Connolley and Gavin Schmidt, as well as from anonymous reviewers at RealClimate in writing this post. I learned a lot!

    Then I’d like to thank these early posters for their very kind comments! Here are some replies:

    Manuel, you are right, not all places were dry and there is a significant difference between the eastern and western Med region when it comes to precipitation patterns. Just check out the observational precepitation trend I show for Istanbul: it looks like it’s getting dryer but 1998 and 2000 got a LOT of rain!!

    Yes AGW could satnd for anti-global warming. Thanks for pointing that out John.

    David Wilson: As Gavin is pointing out we say anthropogenic every day, all day. It means human induced, but you could look that up too, right?

    Aslak Grinsted: The centennial tree ring data is from the World Data Center for Paleoclimatology where the work of Akkemik, Dagdeviren and Aras is published ( The spring observational precipitation data for Istanbul is from NOAA National Climate Data Center.

    If I am not answering anyone’s specific question, it isn’t because I am ignoring you, it is because I don’t know the answer :)

    Comment by Figen Mekik — 22 Oct 2007 @ 9:20 AM

  13. RE: #2 Maunel

    Sadly, Iberian precipitation numbers dispute the value of your anecdote. Total rainfall is decreasing. Total spring rainfall is decreasing.

    ” … intense precipitation (lines d and e in the figure) is decreasing in all seasons (columns are spring, summer, autumn, winter from left to right) while light precipitation (line b) is increasing. Line a in the figure suggests that total precipitation has generally decreased in all seasons over much of the peninsula.”

    ” … light precipitation amounts and days with light precipitation are increasing, but the days with and/or amounts of moderate to very intense precipitation are decreasing. Not surprisingly, they also found “there was a decreasing trend in the mean precipitation value per rainy event in every season. This decrease is consistent with the aforementioned increase of the proportion of light rainfall relative to the total.” “

    Comment by EthanS — 22 Oct 2007 @ 9:26 AM

  14. Ethan, consider the source, you’re quoting from a PR site notorious for making things up and twisting facts to fit the story line they’re paid to present. Look them up.

    Comment by Hank Roberts — 22 Oct 2007 @ 9:36 AM

  15. AGW: Perhaps RC could create an acronym glossary. I usually figure them out myself, but sometimes the use of acronyms here becomes overwhelming.

    Comment by Mark R — 22 Oct 2007 @ 9:53 AM

  16. Although bad land use practices and arson share the blame, AGW is most likely the culprit.

    Bad land use practices are anthropogenic – human-caused – and operate on a scale that could contribute to regional or global warming. The term AGW thus arguably includes changes due to land-use practices, rendering the sentence confusing.

    This would be better: “Although bad land use practices and arson share the blame, CO2 is most likely the culprit.”

    Comment by Glen Raphael — 22 Oct 2007 @ 10:02 AM

  17. Thank you Figen Mekik for a positive article.

    Since there are now several people saying that we humans go extinct in about 200 years because of global warming, is it time for a RealClimate article on H2S?

    Comment by Edward Greisch — 22 Oct 2007 @ 10:12 AM

  18. Here in the Keystone State of Pennsylvania I have noticed something peculiar. The extremes between night and day are increasing, Sometimes I have to put on the heat at night, only to use the air conditioner during the day! Also, my wife got a bad sunburn, one you might get in mid-summer, but it is October. And Denver was seventy degrees one day, and then snowing the next. My analogy is once you lose control of a car, you overcompensate to correct and then you steer in the opposite direction, etc. This is what is happening to the weather patterns. When will we actually “crash”? It may be as soon as next year.

    Comment by PaulM — 22 Oct 2007 @ 10:43 AM

  19. RE: Spencer

    Someone can correct me if I am wrong, but I believe that you are talking about specific humidity while Lawrence is talking about relative humidity.

    There was a recent (last week?) paper in Nature by Willet et al that indeed confirmed that specific humdiity has increased by ~0.25 g/kg since 1975, and that this increase is most likely due to human influences.

    On the issue of relative humidity (Lawrence’s point), I was under the impression that relative humidity remains fairly constant — even with the changing of the seasons. A seminal paper on that issue is Manabe and Wetherald, 1967 (JAS). The prevailing wisdom on relative humidity’s constancy may have changed in recent years, but just last year I heard a prominent climate dynamicist say something along the lines of, “it’s a good approximation, but we still don’t have a satisfactory dynamical explanation for why it is the case.”

    However, I am just a geochemist. Perhaps Gavin or one of the other climate dynamicists on this site could elaborate.

    Comment by Brian — 22 Oct 2007 @ 10:49 AM

  20. Thank you for a very informative and readable comment Madam Mekik.

    It’s certainly tough being a Prof, almost as tough as being a member of the RC Group : I had a look at your Prof ratings and your students like you – well done.

    I dont post on this site very often because I feel I have nothing of scientific interest to say, but I do post on other sites : principally The Guardian and The Economist.

    When I post on global warming I ask basic questions : where are all the mediterranean (and continental) people going to migrate to (to live in a climate where 40+ is the rule rather than the exception takes some doing), where are future food supplies going to come from, and so on. And it is not only drought : geopolitical behaviour is involved too – an example is the Russian position on defending their southern borders and extending their northern ones.

    So my point is the same point I made in a recent previous thread about the accessibility of science to the average person on the street using simple numbers and simple measures. Everyone knows that the Dow Jones went down last Friday but nobody pays any attention to the NAO.

    If you tell me that the NAO is a good measure then we should broadcast that in all office lifts (elevators) in mediterranean countries and on the front pages of all newspapers, at the same time as refining the models to make the NAO the reference statistic. Now, it may turn out that a refined NAO will be a better statistic, but we have to start somewhere with a good proxy. I am not sure that the problem of inaction on global warming is either ignorance or apathy : I suspect it is more to do with engagement.

    People can engage with a number : particularly one that will punish them.

    The same considerations apply to an index for sea level rise.

    Is it difficult for scientists to come up with a climate index, like the Dow Jones for stock? Is it too un-scientific to do that? Not scientific enough perhaps? Dont want to get your hands dirty with the real world?

    One thing is certain, when the City and Wall St. have something to relate to when assessing their own risks then you will see action on global warming, and law suits.

    The excellent Mr Hansen (and Gavin) in the Hansen et al 2007 paper and in particular with section 6 started to move down the engagement road. Long may it continue.

    Well done RC again, and dont weaken.

    Comment by Eachran — 22 Oct 2007 @ 10:57 AM

  21. Re: #14

    Hank, I didn’t look too closely at the rest of the site – I only found the blog post I cited thru Google. That said, nearly all the text I quoted was summarizing (or quoting) Gallego, et al, 2006, described as:

    “An article in the recent Journal of Geophysical Research puts the spotlight directly on the rain in Spain as four scientists from the Universidad of Extremadura examined precipitation records from throughout the Iberian Peninsula from 1958 to 1997.”

    WCR’s choice of the article and WCR’s (absurd) claim that the findings conflict with the IPCC are silly. But I’ve no reason to doubt the information cited from the recent JGR article, other than that the dataset stops ten years ago. Here’s another source discussing declines in aggregate rainfall in Spain (among other climate change effects and predictions):

    Comment by EthanS — 22 Oct 2007 @ 10:59 AM

  22. Nick O asked:

    Regarding Arctic ice, has anyone given thought to the submarine ice off the coast of Canada, and presumably Russia/on the other side, and how this is likely to react/behave as the Arctic warms up? …

    I’m no expert on buried relic ice, but I watched AIT at the Holiday Inn Express. Assuming it were to melt rapidly and escape into the ocean, wouldn’t water and earth just fill its former space and cause little to no increase in sea level?

    On topic, my wife recently worked in Algeria. They don’t have much agricultural land to lose.

    Comment by J.C.H. — 22 Oct 2007 @ 11:04 AM

  23. We do need to be more on the QT about acronyms like AGW, NAO and ENSO. We need an acronym list ASAP to be AOK here. It’s OK if you can’t get one up till next AM, but it should be up PDQ. Anyone with an IBM PC that can see HTML should be OK not just in the USA but also in the EC. TNT,


    Comment by Barton Paul Levenson — 22 Oct 2007 @ 11:26 AM

  24. Wow, that sounds ominous. So does this: . Good thing the eminent environmental economist Richard Tol assured me on another blog that, “Water scarcity and heat stress have no obvious relationship, as water stress does not mean that drinking water is scarce.”. And here I was beginning to worry that the economists couldn’t chutzpah their way out of this. Never fear!

    Comment by Majorajam — 22 Oct 2007 @ 11:33 AM

  25. Hey all, I just stopped by to make the point that I made today in Dr. Mekik’s class that the scientific community needs to move away from the term “Global Warming” and begin to use “Global Climate Change” instead. I am aware that many climate scientists already use this phrase but it still isn’t necessarily “mainstream” at this point. I would like to argue that “Global Climate Change” while more ambigous than “Global Warming” allows for more variations in climate that are taking place to be accepted by those people who aren’t enlightened enough to belive in “Global Warming”. The point was made in class today that the hosts on SportsCenter were dismissing “Global Warming” due to the fact that is was snowing in Denver in October…(gasp!) I contend however, that if the community starts to use “Global Climate Change” more people especially in America where the “debate” still rages will begin to accept the anomolies that we are seeing worldwide that don’t always include warming, drying conditions. Thanks again for the pertinent info Figen, you rule!!!

    Comment by Paul Bourdon — 22 Oct 2007 @ 11:46 AM

  26. Very quick..

    Glen: that’s a great point, thanks. I’ll ask RC folks if we can make the edit.

    Eachran: That is so kind of you to say that you checked my student ratings! I like to teach and I love ocean and climate science, and I think students pick up on both. And pizza. I buy them pizza. :)

    Comment by Figen Mekik — 22 Oct 2007 @ 11:52 AM

  27. Ethan, you write:
    > I’ve no reason to doubt the information cited from the recent JGR…

    Ethan, that’s my point.

    You don’t need a “reason to doubt” — always doubt. Check. There’s far more misinformation out there that Google will find than reliable information. No “Wisdom” button as Cody reminds us.

    You can look these sources of up. WCR is well known for biasing and spinning and taking out of context to claim support for their PR.

    Even if you find a fact, check for omitted context.

    “Trust, but verify.” — R. Reagan.

    “The results of the papers were selectively picked up by the World Climate Report (WCR), a publication sponsored by the Western Fuels coal consortium, to assert that current human emissions will not lead to global warming …..”

    Comment by Hank Roberts — 22 Oct 2007 @ 12:19 PM

  28. There is a good, long, piece in this morning’s NYT ( about water problems in the American West. More about the problems and what people are doing about them than the “How” of climate of climate change.

    Looks like 50 million people are at very high risk of AGW induced drought. We may be past the risk management stage, and into the event response phase.

    Re 17
    Denver always had a pattern of sharp weather changes, snowing one day, and sunny the next. What has changed is warm moist air from the Gulf of Mexico coming up in the winter to generate large snow events. The blizzards of my childhood, came out of the North as cold, realtivly dry storms. Now, there are some winter storms around Denver that result in more snow. Since this moisture falls east of the traditional snow catch areas, it does little to help the water problems discussed in the NYT piece.

    Comment by Aaron Lewis — 22 Oct 2007 @ 12:30 PM

  29. [both atmospheric CO2 rise and stratospheric ozone depletion cause a strong polar night vortex. The North Pole is dark and very cold in the winter. This creates a large temperature difference between high latitudes and subtropics. The resulting large pressure contrast forces east-west winds into a stratospheric spiral. And this stratospheric vortex likely causes the NAO to prefer a positive phase.]

    Figen, thanks for a very useful article, could you please spell out a bit more how (a) the CO2 rise and (b) stratoshperic ozone depletion cause a strong polar night vortex? Oh, and what is the polar night vortex? Google finds plenty of references, but all apparently assuming knowledge of the term!

    Comment by Nick Gotts — 22 Oct 2007 @ 12:53 PM

  30. [both atmospheric CO2 rise and stratospheric ozone depletion cause a strong polar night vortex. The North Pole is dark and very cold in the winter. This creates a large temperature difference between high latitudes and subtropics. The resulting large pressure contrast forces east-west winds into a stratospheric spiral. And this stratospheric vortex likely causes the NAO to prefer a positive phase.]

    Figen, thanks for a very useful article, could you please spell out a bit more how (a) the CO2 rise and (b) stratospheric ozone depletion cause a strong polar night vortex? Oh, and what is the polar night vortex? Google finds plenty of references, but all apparently assuming knowledge of the term!

    Comment by Nick Gotts — 22 Oct 2007 @ 12:54 PM

  31. Re #18: [Denver was seventy degrees one day, and then snowing the next.]

    This is not all that unusual for any place located near a mountain range. It’s happened here (in the Sierra Nevada) several times this year.

    With regards to the main article, I still wonder how much of this local change is AGW-related, and how much is simply part of the several thousand year pattern of changes that’ve likely been caused by human agriculture.

    Comment by James — 22 Oct 2007 @ 1:19 PM

  32. Perhaps someone could comment on this question: How many years does it take for some new rainfall pattern or temperature regime to cease being ‘unusual weather’ and be generally considered ‘climate change’? For instance, if summertime day-time high temps have been in the 80 F range for decades, but are now in the 100 + F. range, how many years before this ‘extreme weather’ comes to be normal and that a ‘climate change’ has occurred?

    Comment by catman306 — 22 Oct 2007 @ 2:51 PM

  33. “@1 – Does anyone have any idea/predictions whether the ice refreeze in the winter will lead to a lower ice mass during winter?”

    Since the melting season in the Arctic bottomed out there’s not been as much mention of it but I’ve been following Cryosphere Today and it’s clear that the situation is still abnormal. Before this summer their anomaly plot hadn’t gone below -2million sq km, well during the summer they extended it to -2.5 and now to -3! It was only last week that the sea ice area got back up to the previous record minimum (a month late). I wouldn’t be surprised to see a record low maximum this winter. Also I suggested to them earlier this year that they might include a plot of global total sea ice and they have done so (whether it was in response I know not). This is showing a very different trajectory than in previous years.

    Comment by Phil. Felton — 22 Oct 2007 @ 2:51 PM

  34. I am confused. How do you explain that the NAO index displays a negative trend in the last 15 years, as shown in your plot? Shouldn’t it be pointing up due to AGW?

    Comment by viento — 22 Oct 2007 @ 3:00 PM

  35. This is purely anecdotal evidence, but I spent two weeks in Morocco on vacation this spring, and almost everyone I spoke with knew about global warming and knew that it was expected to dry out Morocco.

    Comment by Bob Shackleton — 22 Oct 2007 @ 3:09 PM

  36. Nick Gotts (#30) wrote:

    Figen, thanks for a very useful article, could you please spell out a bit more how (a) the CO2 rise and (b) stratospheric ozone depletion cause a strong polar night vortex? Oh, and what is the polar night vortex? Google finds plenty of references, but all apparently assuming knowledge of the term!

    If I could hazard a guess…

    In the troposphere, greater levels of greenhouse gas tend to raise the temperature as the result of moist air convection from the surface receiving more backradiation. In the stratosphere, above the both the effective radiating level and the tropopause, where one has a negative lapse rate, greater levels of greenhouse gases tend tool result in a net cooling. However, there is an exception: ozone. It absorbs UV directly from sunlight and as such tends to warm the stratosphere. With its depletion the stratosphere tends to cool.

    The temperature differential between the stratosphere and the troposphere results in increased circulation of the polar vortex with its strong downward movement near the center, particularly at night as this is when the temperature differential between the surface (with its greater thermal inertia) and higher altitudes within the troposphere will be greatest. However, I would guess that winter is at least as important as night in determining the strength of the vortex.


    Here is something interesting (albeit from 2001):

    In early winter, cold temperatures result in the formation of a strong circumpolar flow in the stratosphere, known as the Polar Night Vortex. This vortex produces favorable conditions for ozone depletion.

    ….The breakdown of the Stratospheric Polar Night Vortex is an atmospheric event that occurs once or twice each year in the polar wintertime stratosphere. As the polar vortex is formed, sharp gradients of potential vorticity at the vortex edge isolate polar air from the air at lower latitudes, producing conditions favorable for wintertime polar ozone depletion. Rossby waves propagating upward from the troposphere along the edge of the Polar Vortex grows exponentially in amplitude, eventually tearing the vortex apart.

    Comment by Timothy Chase — 22 Oct 2007 @ 3:28 PM

  37. Who somebody is funded by is immaterial. Bad argument. It’s like saying some environmental report was funded by Greenpeace and they’re biased so the paper is no good. Or that the US DOE published something, and the US government is funded in part by engergy companies so everything they put out is biased.

    Comment by Raplh Smythe — 22 Oct 2007 @ 4:03 PM

  38. Nick Gotts, thanks for your question and sorry for my slow response. Actually I am going to offer a quick one now and work on a more detailed one to post later. And thanks Timothy Chase for your answer. Basically as the subtropics become warmer, both the tempertaure and pressure gradient between the poles and the subtropics steepens. During long dark polar night (winter) this gradient causes the east-west winds to coalesce into a spiral called the polar night vortex. The more the subtropics warm, the stronger the vortex whcih presumably keeps NAO in its +ve phase.

    James, I agree with you. Desert makes more desert and agricultural overuse and degradation is adding to the desertification around the Med. People just want to burn a couple of acres to clear off farm land, but because the vegetation is so dry, the fires go out of control. But arson is arson!

    Comment by Figen Mekik — 22 Oct 2007 @ 4:13 PM

  39. Ps to 36

    It would appear that the “Polar Night” is simply another way of refering to the arctic winter, except as it applies to the pole. As such, the Polar Night Vortex refers to the vortex as it exists during the winter, and my statement “However, I would guess that winter is at least as important as night in determining the strength of the vortex” quite literally makes no sense as night and winter are the same thing.

    Comment by Timothy Chase — 22 Oct 2007 @ 4:13 PM

  40. Re. #17

    Re. H2S (hydrogen sulfide) extinction possibilities from AGW (human-caused warming).

    “Since there are now several people saying that we humans go extinct in about 200 years because of global warming, is it time for a RealClimate article on H2S?”

    I personally talked to several peer-review publishing scientists in our building (a national federal climate research lab) on this issue of H2S poisoning possibility in our near future (100-200 years.) One is researching and publishing in this area.

    The correct answer according to them (~2 months ago) is “we don’t know…but very unlikely” according to a type of their sort of conscensus. (Note, they are not saying anything like a definite “yes” or “no” and it would be unethical for them to do so with the information they have).

    According to them, it is very unlikely that the conditions necessary for H2S tipping points could be reached in this short time period…mainly the idea that for the major oceans to stop overturning enough in this timespan, to let the oceanic oxygen content decrease enough to stop reacting enough with H2S to start letting the H2S go to the ocean surface and go “airborne” in quantity from the ocean depths (I’m doing his from memory, so one of the details might be off a little). Remember, most climate models do not predict the North Atlantic thermohaline circulation (MOC) cutting off for at least 100 years.

    That being said, a non-publishing meterologist in this disciplinary area)/(who is also paleoclimatist-leaning in this building) stated to me that we need to keep researching this to make sure…especially as more evidence keeps surfacing (ooooo, I’m full of puns today) that climate can change more rapidly than we had previously thought. So at least several of the world’s top publishing scientists are not losing sleep about this (unlike AGW according to them).

    …BUT one was extremely concerned about the ACIDIFICATION OF THE OCEANS (as are a lot of publishing scientists in my building) due to humans putting 30+% more CO2 into the atmosphere and then into the oceans. This makes the oceans more acidic. This can cause problems with coral and plankton and their shells…and the base of the oceanic food chain.

    Comment by Richard Ordway — 22 Oct 2007 @ 4:19 PM

  41. as a matter of fact I know very well what Antropogenic means, and if I didn’t, I expect I am one of the few here who has a personal subscription to the Oxford English Dictionary (OED) on-line to look it up, but even at that I had to wonder what AGW was, GW I knew, AGW was new to me, and the author did, kindly and according to the drill, write it out the first time he used it, all very correct

    a famous Canadian thinker, Northrop Frye, said this: “the simple is the opposite of the commonplace”, so I am thinking that wheras Antropogenic is quite absolutely correct, it is maybe just not necessary (?)

    just a thought y’unnerstan … Gwynne Dyer has pointed out a disturbing spinoff from the recent fires in Greece ( I too have wondered what it may be like when large groups in urban settings begin to feel the pinch – it might not be very pretty

    I know this is off topic, not so far in my mind (which thinks that communicating freely may be one of the few antidotes) but off-topic nonetheless, so I will stop lest Gavin [Edit] me again :-)

    Comment by David Wilson — 22 Oct 2007 @ 4:31 PM

  42. Re #25

    Paul, I fully understand you perspective on ‘Global Warming’ vs. Global Climate Change’.

    My perspective is that there are certain special interests that would love it if the scientific community would not use the term ‘Global Warming’.

    In my view, when it comes to publicly paid for science, science should serve at the pleasure of public and policy maker understanding.

    While this is a web site for science, it is being read by the public and hopefully policy makers. I believe that it is important to use the term ‘Global Warming’ as it is illustrative and accurate to a large degree.

    Actually Global Climate Change could mean global cooling also. In this case I would argue that the illustration of the descriptive is ‘very’ important to the presentation and therefore understanding of the audience this science is meant to serve, the public and the policy makers.

    Comment by John P. Reisman — 22 Oct 2007 @ 4:35 PM

  43. #41: Tha author is a she :)

    Comment by Figen Mekik — 22 Oct 2007 @ 6:23 PM

  44. “…both observational and reconstructed data follow a similar trend…”

    I don’t understand this inference. I assume that the green dots in your graph are 5-year averages (there’s way too little year-to-year variability for them to represent individual seasons), so the green and red can be compared directly. The green and red seem to have similar changes on the scale of 5-10 years, but the trend from 1950-present in the observed (green) seems to be nearly zero, compared to a massive negative downward trend in the reconstructed data.

    Comment by John Nielsen-Gammon — 22 Oct 2007 @ 6:48 PM

  45. Re: #42

    John, are the interests you’re referring to the automotive and petroleum industries? I totally understand where you’re coming from with Global Warming and would agree that the term is very much illustrative and accurate to what trends we are currently seeing worldwide. It’s just discouraging for me as an American to know that our country lags far behind the rest of the world when it comes to accepting AGW as a fact. It seems like for whatever reason, non-believers in this country are so quick to point out any climate change that isn’t directly warming as evidence that AGW must not be real. I know that progress is being made everyday, but there are many people in the US that cling so tightly to what the idiot box (TV) tells them that I find it hard to see them changing their opinions until their house on the Beach is swallowed up by rising sea levels.

    Comment by Paul Bourdon — 22 Oct 2007 @ 7:28 PM

  46. #44 John Nielson-Gammon: You are right. I was just trying to point out that the ups and downs in both curves (red and green) follow each other. And yes, both the red and green are 5-year running averages. The pink too of course.

    #34: viento: I haven’t been ignoring your question. What I get from the figure is the gray bars are positive and the white bars are negative. I don’t know why both 2’s on the axis are labeled -ve. Maybe Gavin or another RC editor can tell us why.

    [Response: Fixed. It was like that in the original figure, but there is no doubt that +ve is up. – gavin]

    Comment by Figen Mekik — 22 Oct 2007 @ 7:40 PM

  47. Re. #37, Raplh Smythe:

    Who somebody is funded by is immaterial. Bad argument. It’s like saying some environmental report was funded by Greenpeace and they’re biased so the paper is no good.

    No, it’s like saying that if a climate science paper was funded by Greenpeace, one should be question the study’s impartiality. There is considerable peer-reviewed evidence that studies funded by organisations that have a financial interest in the study’s outcome are much more likely to reach the desired conclusions than those which aren’t – see, for example, Okike et al 2007; Vartanian et al 2007; and Peppercorn at al 2007.

    Comment by Dave Rado — 22 Oct 2007 @ 7:43 PM

  48. That’s what happens when you build freeways through the middle of town, and there by cut off and turn nice neighborhoods into shanty towns, and furthermore cut down trees to build car parks. To boot, the place is now ringed by shanty towns. How they have fouled the place.

    Comment by SteveSadlov — 22 Oct 2007 @ 8:24 PM

  49. Re: #11 and #19 Thanks Spencer and Brian for your replies.

    Spencer you have not yet given me reason to abandon my conjecture and the bathroom analogy. The same laws of physics apply in my bathroom and the earth. As Brian stated, you did miss the point that I am talking about relative humidity.

    My gut feel is that relative humidity averaged out over the entire earth is in the decline (driven by the increased ratio between atmospheric to ocean temperatures). Certainly in Australia, humidity levels are so low that any clouds that do blow in just evaporate away!

    I will abandon my conjecture, if worldwide, the amount of low to medium level cloud cover has increased as a result of AGW. I suspect it has reduced. Does anyone have the numbers?

    Comment by Lawrence McLean — 22 Oct 2007 @ 8:32 PM

  50. The Mediterranean south west of Western Australia experienced a “step decrease” in rainfall from the mid 1970s continuing to the present. This comprised a loss of early winter rainfall and an overall reduction in average annual rainfall of about 15%. The rainfall reduction has had implications for fire risk, surface and ground water resources and associated implications for agriculture, biodiversity and so on. Attribution of this change in rainfall to AGW has not been determined, but it is a suspect. Further information can be gained from the climate research program website concerned with this matter: The 2007 AMOS conference included a session on the SAM for which see

    Comment by Richard McKellar — 22 Oct 2007 @ 10:42 PM

  51. Re: #45


    It spooks me a little whenever anything in science is treated as a popularity contest – when people seem to be concerned about whether the US “lags far behind the rest of the world when it comes to accepting AGW as a fact”. Facts are not subject to majority opinion.

    I also think the word “fact” tends be used a bit too loosely in these debates. That the Sun is larger than the Earth is a clear fact. Evolution may be a fact, but would it be proper to say that any specific model of evolution is a fact? Probably not. In the same way, I have no problem with saying that “GW” is currently a fact, but I have a little trouble when the “A” is dropped in front of this acronym. Anthropogenic components play a role, but the extent of that role is by no means a fact. Does anything with a certainty less than 100% constitute a “fact”? When the role of this human factor or that is given a probability of say 95%, what does it mean to say that such a thing is a fact?

    Suppose that, for whatever reason, humans were really crappy astronomers and we could only estimate with 95% certainty that the Sun was larger than the Earth. Under such conditions, it would not be a fact that the Sun is larger than the Earth. [Bizzare analogy I admit, but I think it makes my point clear.]

    Comment by Rob Huber — 22 Oct 2007 @ 11:40 PM

  52. In The Guardian today by David Adam. Is this news to anyone.

    “Scientists warned last night that global warming will be “stronger than expected and sooner than expected”, after a new analysis showed carbon dioxide is accumulating in the atmosphere much faster than predicted.

    Experts said that the rise was down to soaring economic development in China, and a reduction in the amount of carbon pollution soaked up by the world’s land and oceans. It also means human emissions will have to be cut more sharply than predicted to avoid the likely effects.

    Corinne Le Quere, a climate expert at the University of East Anglia and British Antarctic Survey, who helped conduct the study, said: “It’s bad news because the increase in atmospheric carbon dioxide has accelerated since 2000 in a way we did not expect. My biggest worry is people are discouraged by this and do nothing. I hope political leaders will act on this, because we need to do something fast.”

    The study worsens even the gloomy predictions of this year’s report from the Intergovernmental Panel on Climate Change. The IPCC, which shared the Nobel peace prize this month with Al Gore, said there were only eight years left to prevent the worst effects of global warming, by acting to curb emissions.

    Dr Le Quere said: “We are emitting far more than anticipated when the IPCC scenarios were drawn up in the late 1990s.” Global carbon dioxide emissions from fossil fuel burning has risen by an average 2.9% each year since 2000. During the 1990s the annual rise was 0.7%.

    The new study explains abnormally high carbon dioxide measurements highlighted by the Guardian in January. At the time, scientists were puzzled why dozens of measuring stations across the world were showing a CO2 spike for 2006, the fourth year in the last five to show a sharp increase in the greenhouse gas.

    Carbon dioxide concentration in the atmosphere is measured in parts per million (ppm); from 1970 to 2000, the concentration rose by about 1.5ppm each year; since 2000 the annual rise has leapt to an average 1.9ppm.

    The new study, published in the US journal Proceedings of the National Academy of Sciences (PNAS), says three processes have contributed to this increase: growth in the world economy, heavy use of coal in China, and a weakening of natural “sinks” – forests, seas and soils that absorb carbon.

    Pep Canadell, executive director of the Global Carbon Project, which carried out the research, said: “In addition to the growth of global population and wealth, we now know that significant contributions to the growth of atmospheric CO2 arise from the slowdown of natural sinks and the halt to improvements in the carbon intensity of wealth production.”

    The overall growth of the economy is the only one of the three factors accounted for in scientists’ forecasts of climate change, which means the growth in atmospheric CO2 is about 35% larger than they expected. About half of this is down to the Chinese reliance on coal, which has forced up the carbon intensity of the overall world economy since 2000, reversing a trend of increasing energy efficiency since the 1970s. The rest of the rise is explained by the weakening of the natural carbon sinks.

    Scientists assume about half of human carbon emissions are reabsorbed into the environment, but computer models predictincreased temperatures will reduce this effect. The PNAS report is the most convincing evidence so far that the global sinks have weakened over the last 50 years, though the large natural variations in carbon exchange between the earth and the atmosphere mean the team can be only 89% certain they have found an effect, short of the usual 95% confidence required to publish scientific findings.”

    I especially liked (irony) the last bit contrasting 89% with 95% and the implied criticism of the Chinese.

    I am not a pessimist : at least not yet.

    I shall repeat again, sorry to be so boring, that we really need a deadline for people to work to : a real deadline, a measurable effect which people will know approaches and more rapidly as each year passes. The amount of carbon in the atmosphere doesnt give that immediacy and doesnt engage people : it’s complicated understanding the consequences of yet more carbon.

    But an NAO based index for drought and a similar one for the mass balance of ice sheets for sea level rise might just do the trick.

    I shall pen a message to our world leaders today.

    I was wondering if Madam Mekik might feel qualified to comment on the oceans’ capacity to absorb : I think that I read on this site that wind change in the S Pacific reduced the churn of water and reduced that part of the world’s capacity to absorb by 30%.

    By the by, I hope Madam Mekik wasnt offended by my reference to her students. It is just that if I dont know someone I check up on them to see if they might be OK. Scientists are no different from lawyers, doctors and other professionals : you get good and not so good.

    The reason I come to this site for info is that I trust the Group to get it right. The fact that they allow you to comment as a guest is all to the good.

    Comment by Eachran — 23 Oct 2007 @ 12:11 AM

  53. Barton, excuse my acronym ignorance but what do QT and PDQ stand for?

    David Wilson: AGW is an acronym frequently used on this site, and I didn’t want to repeatedly write “anthropogenic global warming” in my text to save space. However, it is important to qualify GW with “anthropogenic” because [1] that is the point that is most disputed by denialists-whether global warming (or climate chnage as Paul wants to say :) ) is indeed caused by human activities, and [2] our planet has experienced global warming in its past when no human being was around like about 55 milion years ago during the Paleocene-Eocene Thermal Maximum.

    Eachran: Of course I am not offended that you checked up on me. That’s what the internet is for…

    Comment by Figen Mekik — 23 Oct 2007 @ 5:42 AM

  54. Re. #45

    Paul, Yes, we are lagging behind and that also has many factors, I think much can be attributed to our system of education as well as media systems that are more predatory than informative (referring to much of what is generated through the ‘idiot box’ as you say. There is not enough space here to discuss the problems of lack of foresight and lag time in governance.

    If people learned that media is in many ways inherently flawed with regard to factual transmission of information, then we could make faster progress. But in many ways the public may in fact be hypnotized by this media for the reasons stated above.

    Based on my observations, and what I am hearing, the energy industry that is engaged in using petroleum wants to keep the argument alive while they are figuring out ways to exploit the future energy development that is needed. basically they want to buy some time to come up with solutions that will make them money. Much like the tobacco argument, they will work to reduce their culpability in favor of profit and advantage as they see it, at any given point in time.

    Government policy could help in restructuring tax basis in order to help speed up transition processes but there are a lot of special interests in the way still.

    If you have noticed, the energy companies are already starting to flaunt their green feathers and that has an effect on the public subjected to such ads. The fact that green energy from Chevron is being touted as a banner to prove they are green does not negate the fact that the oil they sold has likely caused billions of dollars of damage past, present, and future. Like the tobacco industry, these questions will be addressed sooner or later and we will all have to work our way through it.

    It will take a lot of understanding to address the bigger questions pertaining to: humans using energy, industrial humans use more energy, and we are using too much energy, and/or from the wrong source. None of these subjects will be easy to cope with.

    Comment by John P. Reisman — 23 Oct 2007 @ 5:58 AM

  55. I’m sure I recall that 5 years ago an increase in global average precipitation was predicted by now, the term being ‘wetter, warmer world’. No mention of ‘global drying’. The term ‘oscillation’ suggests counterbalancing effects. I assume that global mean rainfall statistics are kept.

    I’ve noted that rain proneness seems to involve more than just temperature and humidity; why for example thin wispy cloud can produce rain and dark billowing cloud does not. Is there some Factor X at work?

    Comment by Johnno — 23 Oct 2007 @ 6:55 AM

  56. [[Barton, excuse my acronym ignorance but what do QT and PDQ stand for?]]

    “Quick Time” and “Pretty Damn Quick,” respectively.

    Comment by Barton Paul Levenson — 23 Oct 2007 @ 7:31 AM

  57. Rob Huber asked: “When the role of this human factor or that is given a probability of say 95%, what does it mean to say that such a thing is a fact?”

    Rob, actually, there are very few things in life that are subject to 100% certainty, so science has learned–and is still learning–how to deal with such propositions. Probability can have many meanings–from the inherent probabilistic nature of quantum mechanics to the measure of uncertainty in flipping a coin. There are different ways of dealing with these different probabilities.
    If we flip a coin and it comes up heads, we can say little about whether the coin is “honest” (equal probability heads and tails). However, if we flip it 10 times and it comes up heads every time, we would have strong suspicions of its honesty, and after 100 times, we would have a virtual certainty that we were dealing with a trick coin. Note, however, we can never state as a “fact” that the coin is dishonest. Now, let’s say we flip a coin and it comes up heads, 19 straight times. Are you going to bet on tails on the 20th toss? How about if I give you 20:1 odds? That is one measure of a probabilistic “fact”.
    After 150 years of climate science, we have a model that has flushed out the basic drivers of the theory and their relative importance to a high degree of confidence. We have lots of evidence from multiple independent investigations that humans are affecting climate. We have NO evidence that strongly contradicts this hypothesis, albeit there are some studies where the evidence has been ambiguous. So, I ask, on what empirical basis would a scientist reject anthropogenic causation? Or put another way, the coin has come up heads (anthropogenic) 19 times. How are you going to bet?

    Comment by Ray Ladbury — 23 Oct 2007 @ 8:02 AM

  58. This is a well written and chilling article by Figen Mekik deserving of a wider circulation – to help address the issue of “lack of awareness” (as raised in #51 above) and to emphasise the need for more of a focus on local and regional studies in the debate on global warming / climate change.

    The earth is warming, much of the warming is man-made arising primarily, at this stage, from emissions of CO2 (as Arrhenius predicted in the 1890s), natural sinks are being depleted, positive feed-backs are starting to speed up the rate warming, and local climates are changing as this extra energy is redistributed by natural circulation processes.

    In the debate on global warming / climate change there has probably been too much emphasis on global and annual temperature means. The general public finds it difficult to identify with, and see the local relevance, of such a focus. The public needs to know what global warming / climate change means to them, at the local level, where they live. Scientists need to develop ways to better understand local impacts and to provide this information to a wider audience.

    This article by Figen Mekik is a welcome contribution to this process.

    Gareth Evans

    Comment by Gareth Evans — 23 Oct 2007 @ 8:24 AM

  59. #29 Nick Gotts:

    Sorry for the somewhat delyaed response. First off, yes the “polar night” is the polar winter. Six months of darkness with temps at -70 to -100 degrees C around the north pole.

    CO2 rise and AGW causes the subtropics to become warmer which creates a stronger temperature and pressure gradient between the cold polar night (winter) and the subtropics. This steepened gradient is what causes the east-west winds in the stratosphere to develop into a vortex, a spiral. And many researchers think this spiral (cyclonic circulation or polar night vortex) is where ozone-destroying chemicals are trapped, like chlorine. In spring the sunlight causes photochemical reactions which break down ozone in the stratosphere. And as the ozone is depleted in the stratosphere, it creates an additional reduction in sea level pressure, thereby exacerbating the gradient in sea level pressure between the tropics and poles. This increases the strength of the polar night (winter) vortex. This last part about ozone is more important for the south pole and Antarctica though.

    Comment by Figen Mekik — 23 Oct 2007 @ 9:08 AM

  60. #41, “anthropogenic” would not be necessary, except for denialists who partly (in addition to saying GW is not happening) argue that GW is happening, but not due to us.

    I’ve never had trouble with the term. But then I’m an anthropologist.

    Comment by Lynn Vincentnathan — 23 Oct 2007 @ 9:25 AM

  61. Question:

    Is there a current summary out there anyone is aware of that measures crop yields on a regional and global basis?

    Comment by J.S. McIntyre — 23 Oct 2007 @ 9:48 AM

  62. #58 Gareth Evans:

    Thanks so much for your very kind words. I am not anywhere near being in the league of the editors at RC in climate sceince, so I consider it a huge honor and privilege that they post my commentaries. This gives me a chance to interact with people (other commenters) I wouldn’t normally be able to speak to about topics that I find interesting or concerning. And I really appreciate it that it is getting positive responses from the commenters. Thanks again.

    Comment by Figen Mekik — 23 Oct 2007 @ 10:11 AM

  63. RE (#17 & 40) hydrogen sulfide outgasing and killing off large segments of life on earth. It doesn’t really matter when it might happen (I myself figured in a couple of thousand years, maybe more), but that we are currently pushing the system in that direction, and there will be some tipping point (I think soon), beyond which it will more or less be a done deal for the distant future. In other words I’m not too concerned it will happen to me in my lifetime, only that I may be causing it to happen to others — and it doesn’t matter whether those others are in the century 2300 or 4300.

    RE # 51 & “Anthropogenic components play a role, but the extent of that role is by no means a fact”

    For people looking beyond mere cognitive rational scientific facts into how it relates to them on a emotional level — such as what’s my part in it & what can I to help the situation? — the “anthropogenic” is most important.

    However, in answer to anyone saying the human role is small or nil, I would answer that it means that we must reduce our GHGs all the more to effect even a small slowing this GW in hopes of saving a few lives.

    Comment by Lynn Vincentnathan — 23 Oct 2007 @ 10:13 AM

  64. Re 61
    I mostly use USDA numbers. (!ut/p/_s.7_0_A/7_0_1OB?parentnav=AGRICULTURE&navid=CROP_PRODUCTION&navtype=RT)

    FAO also does numbers.

    Financial advisors supply research related to commodity futures that include grain and meat.

    The food and grain producer’s organizations track conditions related to projected markets and sale prices. (Farmers need to know how much to plant and whether to sell at harvest or hold for better prices. Animal producers need to know if they should buy at harvest or wait for lower prices.)

    Perhaps the best source is “Feed Stuffs”, which is a weekly publication by subscription.

    Comment by Aaron Lewis — 23 Oct 2007 @ 11:07 AM

  65. Re #59 I assumed that polar amplification will reduce the temperature gradient. Can someone explain how this fits in?

    Comment by Adam — 23 Oct 2007 @ 11:11 AM

  66. Re # 24 Majorajam: “…economist Richard Tol assured me on another blog that, “Water scarcity and heat stress have no obvious relationship, as water stress does not mean that drinking water is scarce.”’

    Hmm…tell that to the people of Atlanta:

    ATLANTA, Oct. 22 — For more than five months, the lake that provides drinking water to almost five million people here has been draining away in a withering drought. Sandy beaches have expanded into flats of orange mud. Tree stumps not seen in half a century have resurfaced. Scientists have warned of impending disaster…

    Comment by Chuck Booth — 23 Oct 2007 @ 11:40 AM

  67. A quick question:

    California is being ravaged by fires, is AGW also a contributing factor?

    Comment by Khebab — 23 Oct 2007 @ 11:55 AM

  68. Re. #57: Ray – good comments, well put.

    For some more of the latest on the effectiveness or otherwise of natural carbon sinks, see the below and related links:

    I have to say that I am still v. concerned about the possible long upper tail of the climate sensitivity pdf. It’s bad enough that most people have lack of familiarity with ideas such as the normal distribution, let alone factors/parameters which could heavily skewed such as this. An uphill battle still, I fear.

    Comment by Nick O. — 23 Oct 2007 @ 12:10 PM

  69. Re. #57

    Ray, great explanation, thanks!

    PS, I’m betting on heads :)

    Comment by John P. Reisman — 23 Oct 2007 @ 12:12 PM

  70. For the acronym illiterates, of which I am one, and in fact often keep a second browser page open just to check what I have just read.

    Comment by Ellis — 23 Oct 2007 @ 12:46 PM

  71. Congratulations Figen Mekik for a lucid and enlightening report on the Turkish and Med region, which combined with the feedback from climate scientists, t’other scientists and lesser morsels !!! makes for stimulating and often chilling reading..
    Also coming from a non-Anglo point of view, I would propose that – Alas, however, notwithstanding …most politicians (democratically elected or otherwise) with an average life span of 8 to 12 years and civil servants in the majority of countries HAVE, ARE and WILL in the future of ‘climate change’ be less, less inclined and/or able to implement effective awareness programs and ‘adapt to extreme climate events’ measures.

    Actions speak louder than words – as amply demonstrated by the continuous utterances from the British government and Prime ministers regards climate change etc:, Having lived in England and 4 of her former colonies there is little evidence to support the implementation of widespread programs concerning ‘adapting to climate change’. France is certainly no better – Mon Dieu, radioactive clouds originating from Chernobyl stopped at the French border because they didnt understand French…now that is positive climate engineering !!!.
    However at least in Germany, where I have scurried to, there is a physical scientist, Angela Merkel as Chancellor,promoting and endeavouring to implement a wide range of measures. I have the impression that across the broad political German spectrum this position is adhered to and is the case in Scandinavia, Holland, Switzerland and Austria. But the automobile industry, petro-chemical industries and olde brown coal are powerful lobbies in Germany…racing along at plus 160km is very much a sacred ‘right’ here. Talk of reducing this is as taboo as proposing the widespread use of seperator-flushless toilets, double clean-grey water systems etc which should become mandatory in certain southern European regions and parts of France and Germany….
    With all due respect, you striving climate scientists can present more and more valid and ‘getting closer to reality models’ you want, but for the average Joe, Pierre, Hans or Nakagawa San (I lived in Japan for 8 years) a practical life style change in adapting to climate extremes will have to be thrust upon him and probably forced down his throat too. Certainly, 2-3 year drought-flood cycles in most industrial countries will oblige the implementation of more effective and UNPALATABLE measures while shifing the emphasis from often dubious democratic processes to ‘every day survival’ security and maintenance.

    Moving between RealClimate.Org and the InformationClearingHouse (US,foreign misadventures and geo-strategy)with their lively blogs helps to edge me towards a more ‘realistic’ but ‘pragmatic’ outlook on our ‘3 steps forward 2 steps back’ approach to ‘climate change’ and ‘peak oil’..
    Thanks for a wonderful source of honest and straightforward news reporting & discussion..

    Comment by Svend Jensen — 23 Oct 2007 @ 12:51 PM

  72. re 67

    A quick question:

    California is being ravaged by fires, is AGW also a contributing factor?


    Comment by J.S. McIntyre — 23 Oct 2007 @ 12:56 PM

  73. Mr. McIntyre, it takes a long time to detect whether there’s a change —there are baseline studies:

    “Microscopic charcoal from varved Santa Barbara Basin sediments
    was used to reconstruct a 560-yr record (A.D. 1425 to 1985) of Santa
    Ana fires. Comparison of large (>3750 mm2) charcoal with documented
    fire records in the Santa Barbara Ranger District shows that
    high accumulations correspond to large fires (>20,000 ha) that occurred during Santa Ana conditions. The charcoal record reconstructed a minimum of 20 large fires in the Santa Barbara region during the study period. The average time between fires shows no distinct change across three different land use periods: the Chumash period, apparently characterized by frequent burning, the Spanish/ Early American period with nominal fire control, and the 20th century with active fire suppression. Pollen data support the conclusion that the fire regime has not dramatically changed during the last 500 yr. Comparison of large charcoal particle accumulation rates and precipitation reconstructed from tree rings show a strong relationship between climate and fire history, with large fires consistently occurring at the end of wet periods and the beginning of droughts.”

    It’s the same problem as with hurricanes — people like the locations and build in them, over and over.

    Comment by Hank Roberts — 23 Oct 2007 @ 1:34 PM

  74. How can the NAO, being an index for the climate in winter be measured through tree-ring width/density which responds to the summer climate?

    [Response: In Morocco, the trees are most sensitive to winter precipitation – not summer temperatures. Hence that is what gets reconstructed. – gavin]

    Comment by helen — 23 Oct 2007 @ 1:36 PM

  75. AGW ??? – California ravaged by fires…
    Not only, but also Greece (not even serious cadastral, even GIS-GRASS coverage..I doubt if 600 million euro emergency EU funding will change an iota..), Spain, Portugal, Australia, southern France, Croatia, Bulgaria etc ravaged by fires..

    other valid contributing factors are often:
    – inappropriate bush-undergrowth management which is overgrown and unchecked without grazing, human intervention -and ‘quick burning’ fire is an essential ecological element in many regions..

    – inappropriate highly inflammable trees and bushes planted too near and too densely toresidences ie hi-oil content,’exploding’ behaviour, not regularly pruned…Fire-resistant trees (to a degree) are listed and studied

    – inappropriate maintenance of fire breaks – labour is expensive and hilly terrain is sweating- but of course high wind driven fires can jump most breaks
    – VERY INAPPROPriate housing materials and design, looks great and burns great !!! Check out for example some Ozzie ‘Permaculture’ recommendations, especially David Holmgren, regarding ‘fire proof’ housing and building materials. The fires in Victoria state Oz, Ash Wednesday 1980s ?? etc were real killers almost hitting greek 2007 fatality levels..but folks learnt from it..
    – Finally… Too many people and too many houses in high risk areas and unregulated wishy-washy urban planning- German, Austrian and English floods 2002 to 2007 epitomize ineffective urban planning for recognized natural disasters..

    Fires are part of our future – we can and must adapt accordingly…
    AGW is the icing on the cake…’cuse the pun !

    Comment by Svend Jensen — 23 Oct 2007 @ 1:45 PM

  76. John and Nick,
    Thanks. Good to see somebody hasn’t succumbed to the gamblers fallacy.

    Comment by Ray Ladbury — 23 Oct 2007 @ 2:01 PM

  77. Perhaps a new post is needed, to talk about the SoCal wildfires.

    That is a dry, hot region, getting drier and hotter. The mountains which artificially feed that region with water are losing their snowpacks, reducing the water flow even as demand increases exponentially.

    These fires release an enormous amount of CO2, am I correct? The burning of these lands will allow some of the region (much of which is already desert) to turn to desert because their plant life will have been burned off, and there is no water coming to allow new plant life to grow. Am I correct about this?

    In other words, are we witnessing land change based on global warming? The post could also address the American southeast, which is in a drought emergency.

    Are these warming-related? More to the point, is there any way they can be reversed?

    If not, are we not at the beginning of what will become a mass migration away from those areas?

    Comment by Walt Bennett — 23 Oct 2007 @ 2:11 PM

  78. Re: 77

    Your comments are well-taken. Your questions are ultimately unanswerable. This is part of how I get by these days: I don’t have to know the answers. Whoever gave me a right to know anything?

    Sorry for the imprecision. It’s a bit disconcerting, but it can be thought of as intellectual rigor, akin to the Copenhagen interpretation of quantum physics: we don’t know, we probably never will.

    That said, the sentiments behind your questions remind me of that too-famous last stanza of TS Elliot’s The Hollow Men: this is the way the world ends, this is the way the world ends, and so forth.

    Comment by Daniel C. Goodwin — 23 Oct 2007 @ 2:32 PM

  79. Re. #77

    Walt, sounds like this is starting to sink in with you. As to your questions

    yes, yes, yes (generally speaking)

    While singular incidents are difficult to attribute to global warming, trends are. and the trends are more acres burned per year, averaging upwards. So I would say yes, it is related.

    As to can it be reversed? Good question. The faster we take action the better a chance we have to mitigate the affects. There are not short term solutions other than reducing consumption in many areas. Reversing Global Warming is not something that can happen overnight, if we are really ingenious we might be able to reverse the affect in say 100 years, if not then hundreds of years will be required.

    I personally lean towards the innovation capacity and the axiom that necessity is the mother of invention.

    On the other hand, we clearly have some major challenges ahead of us. Let’s just hope we don’t cross too many tipping points.

    Comment by John P. Reisman — 23 Oct 2007 @ 2:44 PM

  80. re 77. Walt Barnett
    Agree suggested new post for SoCal fires, as we ‘is drifting away from Sweatin Med.

    Available space/carrying capacity and Mass migration seen perhaps in a historical perspective of max 1 billion world population living 30-55 years, without provoking TV coverage, was an accepted and viable necessity for some but usually unknown issue for most unless directly concerned..

    Population of US at Dust Bowl time of Steinbeck’s Grapes of Wrath and 10,000s – 100,000 Oakies heading to Calif..?
    Where would your present day Californians trot off too ? New England, Great Lakes ?? as drought is hardly confined to the west coast !!!

    Population of Judea, pseudo-Palestine etc at time of old testament, max. 50,000 to 100,000 ?? plus every 6-7 years fallow farm cycle!!!

    Scant historical evidence of land change-global climate change being reversible, rather scamper away, allow boom-bust cycle with subsequent die-off, wait a few decades -hundred years and perhaps drift back..

    Modern Mass migration away from important areas in Calif, other parts USA, within Europe, within the middle east and northern china etc IS A POLITICAL NO-NO, TABOO SUBJECT to be AVOIDED at all costs.
    It’s political the moment !!
    Apparently, many academics avoid this topic too..
    Apart from suspect CIA-RANK studies..

    Unsubstantiated gossip:: the Dutch government is supposedly providing subsidies-financial assistance to certain !! Dutch citizens to NOT build a house in Holland but move to higher lands of French speak Belgium ??

    Comment by Svend Jensen — 23 Oct 2007 @ 3:11 PM

  81. re 73

    Mr. McIntyre, it takes a long time to detect whether there’s a change —there are baseline studies


    I really wasn’t attempting an answer to the question. The my posting of the two links was not meant as offering an opinion one way or the other, simply as a reference of what is happening this year – and today. Frankly, any opinion I have is just that – an opinion. My apologies if I came off as saying something I didn’t mean to.

    “It’s the same problem as with hurricanes — people like the locations and build in them, over and over.”

    Yes, I know. I have family in the U.S Forest Service stationed in the area that is burning right now, directing a portion of the operation (though there is little they can do until the winds die down, and there is talk they won’t calm for three more days).

    Suffice to say one of the big problems are the development of communities in the area of canyons – canyons that, in Santa Ana conditions, behave as natural blast furnaces. This is particularly bad in the San Diego region. Add to that the Bug Kill that is prevalent throughout the region and the understanding the Southern California has received less rain than even Death Valley averages in a year, and it’s a climate for disaster.

    While I’m watching those fires with interest, the place I’m really worried about is Arrowhead and the areas around it. If that really catches, things could get very nasty.

    Comment by J.S. McIntyre — 23 Oct 2007 @ 3:19 PM

  82. #67 Kebab: “A quick question:
    California is being ravaged by fires, is AGW also a contributing factor?”

    Don’t know.

    Averages, averages averages… including 30+ years of evidence and from multiple locations… that’s what the world-wide climate science communtity works on. No single event can be easily ascribed to AGW (human-caused warming).

    For instance perhaps, the current San Diego fires are just a freak 500 or 1000 year natural event…

    BUT, this sort of increase in fires around the world has been increasing from an average point of view…but you probably want more years of averages from more locations just to make sure… Following are some scientific references on increasing world-wide fires.

    “If climate change is increasing wildfire,. as Westerling et al. suggest,”
    “They show that warmer temperatures appear to be increasing the duration and intensity of the wildfire season in the western United States”

    A. L. Westerling, H. G. Hidalgo, D. R. Cayan, T. W. Swetnam, Science 313, 940 (2006); published online 6 July 2006 (10.1126/science.1128834).

    N. P. Gillett et al., Geophys. Res. Lett. 31, L18211 (2004).

    Balzter, et al. Coupling of vegetation growing season anomalies with hemispheric and regional scale climate patterns in Central and East Siberia, Journal of Climate 20:15, 3713–3729,

    G. R. van der Werf et al., Science 303, [73] (2004).

    Comment by Richard Ordway — 23 Oct 2007 @ 3:22 PM

  83. Thank you for the replies. There seems to be a consensus that the conditions are not likely reversible in the foreseeable future, which is also my view.

    Whether or not warming is a key contributing factor in the prevalence and intensity of these fires, it seems certain to me that much of the area will be left without significant plant life, and that water scarcity will prevent that plant life from regenerating.

    I am wondering if this land change, as well as the inability to acquire water for other purposes – drinking, cleaning, manufacture and so forth – will inevitably lead to migration. I wonder if this is the opening scene of a story which will keep getting told, over and over.

    It really makes me wonder why we cannot effectively desalinate sea water on a large scale. It seems to me that this is an obvious solution in which investment should have long ago been made.

    Instead we keep divvying up declining mountain water. Even if that supply was to remain constant – a complete fantasy – demand continues to escalate.

    The combination of increased demand and decreased supply seems, to me, to be an enormous stressor. When it bends too far it will break.

    Comment by Walt Bennett — 23 Oct 2007 @ 3:48 PM

  84. #46 Again, I honestly do not see how the observed NAO index supports model projections for the future. In the 20th century we have mostly a negative trend – only between 1960 and 1990 was the trend positive. And the trend in the last 15 years is again negative. Is’nt it more reasonable to interpret this just as natural variations, so far?.

    Comment by viento — 23 Oct 2007 @ 4:07 PM

  85. Viento,

    The trend between 1970 and 2004 looks positive and 2007 is a high positive number. Are we talking bout the same graph? :)

    Comment by Figen Mekik — 23 Oct 2007 @ 4:12 PM

  86. RE #67, I’m from California and remember doing a class ecological project on a chaparral forest in the early 60s. We learned that these forests naturally burn every so often, and this would explain many of the past fires.

    However, when you consider that a warming atmosphere holds more water vapor and desiccates the land and brush; and that GW is also expected to increase storms and winds; add in the natural tendency for these areas to burn, and you get what we’re seeing now.

    “Climate” is on a more macro-level of scientific inquiry than weather — it is the aggregate statistics for weather — so climate scientists cannot say a particular event (at the micro-level) is caused by global warming (at least not yet), only that the warming will entail higher probabilities of such events.

    However, since I’m not a climate scientist, I say, yeh, the California mega-fires we are witnessing today are due to global warming (even if its role was merely the straw that broke the camel’s back, so to speak). We live in a globally warmed and warming world, so I say everything that can reasonably be attributed to GW is due to GW (not tooth-aches, of course), unless proven otherwise. We have to imagine what the world would have been like without global warming, and whether the fires (and droughts, and hurricanes, and such) would have been as big or harmful. I think not.

    Also Dr. Mekik raises an important point when she writes, “small perturbations in weather patterns can lead to tragic and costly outcomes.” It is those final inches of floodwater that breach the levee (the ones caused by GW on top of the natural conditions), that last “huff” that blows or burns the house down (that small increment caused by GW on top of natural & other human-made conditions), that often does the most severe damage.

    There are many necessary (but insufficient) causes for such great harms; the addition of GW may finally make the set of causes sufficient for much greater harms in certain cases. Or, as they say, the whole is much greater than sum of the parts.

    I’m thinking catastrophe theory in mathematics might be helpful here, but I don’t know much about it, only the idea that there are other than smooth linear functions, some with big leaps.

    Comment by Lynn Vincentnathan — 23 Oct 2007 @ 5:49 PM

  87. Just an add-on re the SoCal fires.

    The evacuation number is up to one million, the firefighters have given up any attempt at containment because of the winds, and the governor is quoted as saying about 68,000 homes are threatened.

    This is going to be very ugly barring a miracle.

    Comment by J.S. McIntyre — 23 Oct 2007 @ 6:31 PM

  88. It’s interesting to look at these areas on the graphic of the globe on page 16 of the SPM : Projected Patterns of Precipitation Changes.

    Is the future playing a little peekaboo with the present?

    Comment by J.C.H. — 23 Oct 2007 @ 9:45 PM

  89. Mr. McIntyre, where’s your ‘one million’ evacuation number from?
    I’m looking for a reliable source.

    Comment by Hank Roberts — 23 Oct 2007 @ 10:17 PM

  90. Oh.

    Back around 1990, when I first started trying to get some advice about restoring a burnt-over mountain site in N. Ca., the best advice I got was from people around the Mediterranean. They told me that they had accepted it was sure the climate was changing and expected more warming, more extreme weather, and more erosion problems, and said that they were basically building contour berms on difficult sites, just little ditches with raised edges along slopes one above another, as ways of interrupting sheet erosion from wind and water.

    I took that advice — the results were amazing. Each little groove I’d cut by dragging a pickaxe the first fall had by springtime filled up with a little ribbon of black carbon runoff from the burned over hill, and in each of those little trenches there were lined up orange manzanita seeds starting to sprout, and pine seeds, and a whole lot more.

    The other advice I got from the Mediterranean folks was not to clear all the brush, but to make sure that any bare patch had some dead branch laid across it, again to break up sheet erosion.

    And that worked too — each of those accumulated a little pile of dead leaves and pine needles and bits of burned bark, and had a few seeds sprouting, surrounded by the bare gravel the fire had left behind the previous fall.

    This was before the Web, I had gone to Usenet newsgroups for advice. It was way ahead of the advice I got from the local agencies in the USA — there the standard was to pile and burn every bit of fire debris and leave a clean pruned smooth hillside.

    Believing that the worst that has happened in the past is indeed likely to happen again, and probably sooner with climate change moving faster, seems a good idea.

    Comment by Hank Roberts — 23 Oct 2007 @ 10:34 PM

  91. I believe we are about to discover first hand what happened to the water on Mars.

    Too bad there isn’t a lush, green planet next door. ;)

    Comment by tree ocean — 23 Oct 2007 @ 11:15 PM

  92. Walt Bennett wrote:
    > allow some of the region (much of which is already desert) to
    > turn to desert because their plant life will have been burned
    > off, and there is no water coming to allow new plant life to
    > grow. Am I correct about this?

    No. This is normal fire behavior. The big worry is that European and Asian annual grasses (cheatgrass, Bromus tectorum; medusahead, Taeniatherum caput-medusae) will take over like crazy on the burned areas.

    The only tactic I know of for those is expensive — spray the hillside with sugar water, so the soil microbiota can use that plus all the excess minerals and nitrogen in the ash during the winter, starving those fire-adapted invasive grasses. Otherwise they grow like crazy. If those and their ilk can be discouraged for a few years, the native California perennials come back.

    The California Native Plant Association has a lovely T-shirt design.
    It shows a horizontal line, and above the line is a tiny stem and a few little leaves, and below the line is a _huge_ network of deep widespread roots.

    When I worked on my burnt off site, a botanist dug around in the gravel and showed me a California lupine root — a big thing the size of a thumb — and told me it was likely a hundred years old, and would come back fine after the fire if we could discourage the invasive annuals.

    We did. The slopes we worked on — which had burned down to orange gravel and black silt in many places — are thick with lupine after 18 years, and covered with pine straw where we scattered a few branches across them the first winter and left them alone but for attacking the invasives (with flame weeding, during the wet weather just as they set seed).

    Look at any of the So. Cal. fire sites. Look at Yosemite since its big fires. Fire works fine in these environments if it happens often enough, and if it happens gracefully enough — and you manage that by avoiding big piles of stuff that causes huge conflagrations.

    Like, well, houses.

    Comment by Hank Roberts — 23 Oct 2007 @ 11:28 PM

  93. Re. #89, Hank Roberts:

    Mr. McIntyre, where’s your ‘one million’ evacuation number from?
    I’m looking for a reliable source.

    The BBC is claiming “more than half a million”. They don’t cite their source but their fact-checking is usually very reliable.

    Comment by Dave Rado — 24 Oct 2007 @ 1:46 AM

  94. Hank Roberts wrote:

    “Mr. McIntyre, where’s your ‘one million’ evacuation number from?
    I’m looking for a reliable source.”

    Well, not to suggest that the New York Daily News is a reliable source, but the media in general is using the one million figure this evening. Additional evacuations are being ordered as the fires continue, especially since the end of the Santa Ana winds may result in westerly winds turning the fires eastward.

    “Nearly one million Californians were ordered to evacuate their homes on Tuesday night as wind-whipped wildfires roared across the parched landscape from Malibu south to the Mexican border.”

    Walt Bennett wrote:

    “Whether or not warming is a key contributing factor in the prevalence and intensity of these fires, it seems certain to me that much of the area will be left without significant plant life, and that water scarcity will prevent that plant life from regenerating.”

    As Hank Roberts wrote, many California native plants are “fire” species which come back quickly after a fire. Most of the chaparral hillsides will be showing new growth after the first winter rains. Indeed, the cones of some pine species do not even open to release their seeds until they are exposed to fire.

    Some of the lands burning this week were burned in the huge fires of 2003. So the vegetation did re-grow enough in just four years to carry the current fires.

    Unfortunately, many exotic annual grasses are changing the picture in parts of California. In parts of the Mojave Desert, for example, the annual grasses now are allowing fires to spread to some plants that seldom were affected by fires in the past, such as Joshua trees and some cacti. The spacing of these native plants kept fires from spreading in the past, but the grasses allow fires to travel further than they used to.

    If global warming results in extended droughts in southern California, catastrophic fires may become more common, and the species composition of plants and animals may change. But even though parts of California suffered they driest season since humans have been recording rainfall, there still were a lot of plants growing this year.

    Comment by Jim Eaton — 24 Oct 2007 @ 2:44 AM

  95. So far on this thread, we have worries about drought and the ravages of fire, crop yields and migration as well as the normal worries about temperature increase and sea level rise.

    And now for extinctions, in The Guardian today, just to cheer you all up.

    “Predicted levels of global warming could trigger a “mass extinction event” like the one which wiped out the dinosaurs, new research suggests.

    Such a disaster would not necessarily mean the end of humanity, but it could kill off more than half of all the animal and plant species on Earth.

    British scientists have uncovered the first strong evidence of a close coupling between the Earth’s climate and extinctions.

    The researchers from the University of York analysed the relationship between the two over the past 520 million years – almost the whole of the available fossil record.

    Matching marine and terrestrial species diversity against temperature estimates, they found that the range is relatively small during warm “greenhouse” climate phases. Meanwhile, extinction rates are relatively high.

    The opposite pattern is seen when cooler “icehouse” conditions prevail. Then, biodiversity increases and more species survive.

    Climate change predictions for the future fall within the range of the warmest greenhouse phases associated with mass extinction events in the fossil record, said the scientists.

    Dr Peter Mayhew, a member of the York team, said: “Our results provide the first clear evidence that global climate may explain substantial variation in the fossil record in a simple and consistent manner. If our results hold for current warming – the magnitude of which is comparable with the long-term fluctuations in Earth climate – they suggest that extinctions will increase.”

    Computer simulations point to global temperature rises of around 1.5C by the middle of the century, and 3C in the next 100 years. Some experts believe these estimates are too conservative.

    The research is published in the journal Proceedings of the Royal Society.

    Copyright (c) Press Association Ltd. 2007, All Rights Reserved.”

    JS McIntyre, I tried something similar earlier in the year and started with the FAO website which I found to be un-navigable. Fortunately I have a friend there who arranged for the stuff to be dug out for me. If you cant navigate the FAO site let me know : I will be only too pleased to help.

    Coming back to the wider point there does seem to be a requirement for regular updates for each area of worry and the use of indices to communicate this to the general public. It used to be OK to have 4 yearly up-dates from the IPCC but something more immediate seems to me necessary today.

    On agricultural yields alone, I have read recently that the Chinese fear a reduction of between 30 and 40% over the next few decades and there is precious chance that this deficit will be covered by increasing yields generally (I understand 2 to 3% a year under favourable conditions).

    The problem I have is a very good memory so that most stuff I read sticks : but that doesnt help me very much when I try to up-date everything together to give me the current global picture. I think we need that up-date and the obvious candidates to do that are the developed copuntries.

    I am still doing my letter to them and if I get a response I shall let you all know.

    Comment by Eachran — 24 Oct 2007 @ 2:49 AM

  96. I know it’s off-topic but ‘History of mass extinction is a grim lesson on climate change’ at:

    is gathering its quota of carping denialist posts. I have made a number of attempts to post refutations but something has gone wrong, I have yet to find out what!

    Maybe some of you guys may have better luck at putting the record straight!
    The abstract of ‘Fossil record supports evidence of impending mass extinction’ may be found at:

    Comment by ScaredAmoeba — 24 Oct 2007 @ 4:08 AM

  97. I’m from Big Bear Lake, CA. Big Bear only has two escape routes left at this time and no one is allowed up the mountain, except residents. The entire area is at risk. Luckily I’m not there.

    My family all live in SoCal.

    My brother Paul is working the fire lines I think in the Romona area. His children have already evacuated (mandatory) with their horses.

    My mother and sister and family evacuated (mandatory) from Fallbrook. The entire city has been evacuated; they went to a friends in Oceanside (for now). They both keep calling their houses to see if the answering machine is still on, because if it is, they now they still have a home.

    While a single event can not be attributed to Global Warming, I think it is fair to say that global warming contributes to the conditions that increase the likelihood of those single events increasing in number and intensity. Because those conditions are drier conditions, and that is a significant factor in the likelihood of fire, and fire getting ‘out of control’.

    I would also say this is ‘normal’ fire behavior in the sense that this is what fire does. But I would not disconnect these events from Global Warming because they are occurring under the contributed conditions.

    There have been many reports I have read that were from the national forest service and those I spoke with in Big Bear Lake, that have said that the intensity of these fires, because they are burning hotter will decrease the likelihood of life returning to those areas due to the larger destructive capacity of these fires. This will lead to increased decertification.

    With the trend toward less and less moisture, the likelihood of life returning to these areas decreases; made that much more difficult.

    Also, this is not off topic in my opinion. The Mediterranean region is experiencing increase fires in number and intensity also. The problem is global and the California fires are only the most recent large manifestation of the problem.

    What the insurance companies already know is that this (global warming) is going to get expensive. What the politicians have yet to figure out is that this is going to get expensive.

    As to migration, sure no one wants to talk about it, and maybe there are ways to mitigate those potentials. But if we can’t, then yes, migration will become a reality. Will politicians talk about it, not yet. It frightens them. We must talk about it. The sooner the better. So I am very happy this is beginning to be discussed here on RC! No, we don’t know everything, but the more talk, the more potential for real solutions to be envisioned.

    Our best bet is efficiency and action. We don’t have any time left. Each day we wait will make it more difficult to deal with in the future. Until this lesson is learned in the highest levels of government, industry, and in the majority of society, we can expect the global GDP to be affected more.

    As to evacuations, they are now reporting up to a million in the headlines and an estimated 910,000 people.

    The Rice fire is positioned as of 10:30 last night to run over the entire city of Fallbrook. If the Big Bear house survives (hoping), then the family, mom, sister, husband, three kids, will all be living with me.

    Is this connected to Global Warming. I’m not a scientist, but common sense and reason are my rules of thumb. I have to say YES!

    Comment by John P. Reisman — 24 Oct 2007 @ 4:37 AM

  98. #85

    I am looking at your graph with the SLP-based NAO index, thick continous line – which I assume is some type of multi-year smoothing. I see a clear maximum around 1990 and a negative trend afterwards. The positive trend starting in 1970 is not continued after around 1990. If you look at the subsquent peaks after 1990 they get continously smaller. The ‘high positive value in 2007’ was pretty close or even lower than all the 1990’s (with one exception), some years in the 1920’s, some years in the 1990’s and some years in 1880’s.

    I think we have to be honest. An anthropogenic signal should look very different than this graph. The signal is present in many other climatic indices, but certainly not in this one. Not yet.

    Comment by viento — 24 Oct 2007 @ 4:52 AM

  99. #90: Hank,

    That is very interesting. Did you work as an agricultural engineer? I grew up in Turkey and went to college there (MIddle East Technical University in Ankara-great school!). From grade school on, I’ve been taught that the biggest natural threat in Turkey is soil erosion. So early on we were taught about terracing farmland and contour berms. And water rationing in Ankara is nothing new (I grew up in Ankara) but to have it two days on and two days off is the most extreme I have ever experienced. It was usually just several days in a month in the summer that there would be no running water and everyone would be warned well ahead of time to conserve water and fill up reservoirs at home. And not every summer. So this year was pretty scary.

    Comment by Figen Mekik — 24 Oct 2007 @ 5:39 AM

  100. Re: #97


    Thank you for that vivid and in some ways sobering account. I feel for you and all those affected.

    One note of interest: while we all seem to understand that a warming planet will be drier and hotter in places, there is a broad variety of opinions about the nature of the SoCal event and its eventual aftermath. I am not a botanist and have no knowledge of root systems and so forth. What I have been basing my concern on is the decline in available water. Much of the American southwest would already be bone dry without diversion, primarily from the Colorado. As diversion becomes less and less available, this region will have no choice but to assume its natural state, which is dry.

    As I see it, the warming (sucking moisture out of the ground) will complete the job. I have heard reports that SoCal temps are running 10 degrees above normal, which sounds like Dr. Hansen’s 6-sided die came up HOTTER.

    I see a connecting of dots here. I would greatly appreciate an RC post to explore that in depth.

    Comment by Walt Bennett — 24 Oct 2007 @ 9:18 AM

  101. Just looking at the NAO, it reminds me of the temperature trend in the US for the 20th century. The NAO was positive from about 1900 to 1940 as the US trended rising with the combined effect of greenhouse gases and solar variability, near zero or negative during the aerosol era from about 1940 to 1970s as the US trended dropping or flat, then positive with the warming from the late 1970s to present.

    Maybe I am just seeing a pattern which isn’t really there – but if warming results in a stronger Polar Night Vortex and results in the NAO trending positive with milder, rainier weather in the US SE, the teleconnections would appear to be there. The fact that warming has been milder in the US than the rest of the world has been something of a puzzle and I remember Hansen suggesting that the North Atlantic Oscillation might have something to do with it. Of course right now things are rather dry in the US SE, particularly in the Atlanta area.

    In any case, it helps to be able to identify the regional trends so that people will know what is “in it for them.” I would like to think that people’s concerns would extend beyond their own little neighborhoods, but often this is not the case.

    Comment by Timothy Chase — 24 Oct 2007 @ 9:46 AM

  102. re 89, 90

    re the number…mea culpa.

    Picked it up off the news (Yahoo) yesterday. Should have linked it, as the number is back down to .5 million now.

    (Should have known better; reporting in real-time often gets it wrong, going with breaking stories unconfirmed – for example, earlier in the day they were at 500,000, then dropped back to 250,000).

    As for your comments re Meditteranean climate.

    That’s California climate to a “T”.

    When the first post-gold rush surge of population was underway, many people who came to California transported with them the idea that they could plant English Gardens. It worked on the East Coast, so why not here. The idea is now more or less ingraned in the culture of the place. (Side note: something along the same lines happened in Australia, at least in terms of the assumption by settlers that the rules in one place – England – would be the same there. Of course, this wasn’t the case.)

    While English Gardens can thrive along the fog-bound northern coasts, the majority of the state’s climate is not suited to them. But we keep trying, laying down acres of grass and plants not suited to the area which, along with the need to have swimming pools uses up a lot of water.

    Since the first long drought in the 80s some homeowners have changed they gardening philosophy to reflect the way the climate here really is. I’m assuming that as the years go by, we’ll see a lot more of this type of gardening in the state. Then again, some people tend to cling stubbornly to bad ideas, so we’ll see.

    Comment by J.S. McIntyre — 24 Oct 2007 @ 9:48 AM

  103. This is a belated response to Cobblyworlds (#1) and Adam (#65) and it isn’t a complete answer but may shed some light. And I hope that the RC editors will pitch in should my response be incorrect or if they wanted to add something to it. I am a deep sea carbonate dissolution and sea surface temperature paleoceanography person by training, and not at all an atmospheric scientist. Gavin, particularly, has contributed much to this subject in scientific lit. And I got some help from Mike Mann in formulating this response.

    I simplified the cause for the development of the polar night vortex in my post to keep things simple, but the main impact of greenhouse gas (GHG) forcing on the behavior of the NAO index is related more to the vertical and meridional profile of GHG forcing than solely the polar amplification of surface warming. In other words, increasing the concentration of greenhouse gases in the atmosphere strongly affects the development and motion of planetary waves (large scale air waves -or sometimes ocean waves – whose driving force is variations in the Coriolis effect with latitude)from the troposhpere into the stratoshpere. So vertical motion in the atmosphere is enhanced with greater rising motion at high latitudes. This causes cooling north of 55 degrees latitude and warming at lower latitudes. The net result is a stronger polar night vortex high in the atmosphere. The last few sentences of my explanation are mostly paraphrased and simplified from Shindell et al., 1999.

    I hope this is helpful.

    Comment by Figen Mekik — 24 Oct 2007 @ 9:56 AM

  104. re 97

    “I’m from Big Bear Lake, CA. Big Bear only has two escape routes left at this time and no one is allowed up the mountain, except residents. ”


    My sister, who works on the real-time logistics end of fighting fires with the USFS, has mentioned that they’ve avoided disaster in the Big Bear area at least twice in the past few years, but that with all the bug kill its inevitable that it will eventually go.

    “There have been many reports I have read that were from the national forest service and those I spoke with in Big Bear Lake, that have said that the intensity of these fires, because they are burning hotter will decrease the likelihood of life returning to those areas due to the larger destructive capacity of these fires. This will lead to increased decertification.”

    Found this re soil damage:
    Fire can cause soil damage, especially through combustion in the litter layer and organic material in the soil. This organic material helps to protect the soil from erosion. When organic material is removed by an essentially intense fire, erosion can occur. Heat from intense fires can also cause soil particles to become hydrophobic. Rainwater then tends to run off the soil rather than to infiltrate through the soul. This can also contribute to erosion. In actuality, the negative effects of fires on soils are often exaggerated, and many fairly intense fires in western United States forests cause little soil damage. There is also the potential for alien plants to become established after fire in previously uninfested areas.


    This is also interesting, if brief:

    Comment by J.S. McIntyre — 24 Oct 2007 @ 10:06 AM

  105. Hi Figen, no, I’m just an amateur (got a bit past a MA in animal behavior and was studying honeybee behavior genetics when I ran out of grad school money, many decades ago). Can’t give up poking around, and I find amateurs can get amazing help from agency people who know things their agencies can’t or won’t support.

    Like scattering branches across burned areas instead of picking hillsides completely clean, to break up sheet erosion — even when it leaves some ‘burnable’ material out of the burn piles. Like digging the little contour grooves and berms that I learned from foresters in the Mediterranean countries via Usenet. Like spraying sugar water after a fire to cheat the invasive annuals of the flush of minerals and nitrogen the first growing season by feeding the microbiota instead.

    Look at the fire maps from So. California, zoom in on the fires in Google Earth, and many of them are tiny tightly packed developments full of houses (also known as “fuel”) crammed together in canyons surrounded by ‘open space’ — the people could live spread out in fire resistant buildings, but only if they didn’t try to take over all the surrounding land, only if they were willing to live in an area that’s able to burn fairly often, fairly cool, and fairly gracefully.

    After a fire it looks devastated. But the next few years are amazingly full of life coming back out.

    I don’t know how to get people to take interest in what lives on the planet around them, except to get out into the woods early as kids. Once fascinated, always fascinated.

    Comment by Hank Roberts — 24 Oct 2007 @ 12:04 PM

  106. John and everyone else affected by the SoCal fires,

    My deepest sympathies go out to you. This is indeed a horrific tragedy and I wish you great strength and patience. Hopefully the worst has already gone by.

    Comment by Figen Mekik — 24 Oct 2007 @ 5:35 PM

  107. Can you tell us anything about fire planning in Turkey?
    Intervals between fires normally?
    Lessons learned?

    Comment by Hank Roberts — 24 Oct 2007 @ 6:58 PM

  108. As always the postings on this site are superb.

    An acquaintance observed that the social sciences have not weighed in on either gradual global warming (which seems less likely by the day) or abrupt climate change (which seems more likely).

    Forecasts of specific weather alterations are likely to fall to the simplest chaos theory models, much like forecasting the weather five days out. Forecasting social disruption is easier, but I’ve not read anything academically rigorous. This may be due to the fact that nearly every forecast is likely to be derided as apocalyptic. This is a sad commentary on the social sciences.

    We’re being put to the test as a species. We’re hard-wired to respond to the tiger but blithely indifferent and insensitive to broad patterns and to long term potentialities. To ‘weather'(sorry there’s more than one person falling into puns) this looming crisis and maintain the basis of civilization we need futurists and visionaries who can tie all the pieces together.

    This may not be directly in the topic area of RC but it’s definitely something that will be necessary to a full discussion of this topic.

    Any social scientists out there?

    Comment by D Pecan — 25 Oct 2007 @ 3:48 AM

  109. 105 Hank Roberts – Keyline designs PA Yeomans..
    Soil moisture retention and surviving fires in rural landscapes..
    More suitable for rural landscapes and reasonably hilly topograpy are the well tested ideas from P A Yeomans ‘KeyLine designs’ in Australia dating back to the 1950s. Also incorporated into Permaculture designs..

    BASED on strict adherence to accurately measured contour lines, water channels and grid lines, berms and when the rain does fall on an irregular basis, it falls keeping it localised and allowing penetration..Also sometimes practice of a ‘dip rip’ ploughing to improve soil moisture retention..
    Google : Keyline Designs by P:A Yeomans – interesting homepage

    Sadly, San Diego back country area is too hilly, too densely populated for Keyline applications..

    Comment by Svend Jensen — 25 Oct 2007 @ 7:12 AM

  110. Hank,

    I’m working on your question… Just some news: my summer vacation spot in Turkey, Bodrum , right on the corner of the Aegean and the Med is having massive forest fires as we speak. So far 1100 acres of land, 200 thousand pine trees and 10,000 olive trees have burned!

    Comment by Figen Mekik — 25 Oct 2007 @ 2:44 PM

  111. Some observations on the Mediterranean area.

    There are some 30 countries around this sea. These have a total population of about 450 million, of which 186 million live in the European Union and 260 million outside it on the southern and eastern shores. Water is the limiting factor for ecology, agriculture and cities in the area.

    Perhaps the most important background factor is the population age structure. The EU faces an increasing ageing problem, with a disproportionate number of people approaching retirement age. Outside, on the southern and eastern shores the enormous problem is too many children and youths, their education and employment prospects. Median age on the EU side is 40 years, in the rest of the region it is 24 years.

    Also the per capita GNP is widely different: 26.500 USD in the EU and only 6.500 USD outside.

    There is a long history and a multitude of links across the Mediterranean. Of major significance is also that some 25 million “Europeans” have kinship, clan and close cultural ties with the outside.

    A shift in climate patterns, and particularly the predicted decline of precipitation, is truly the last thing the region needs.

    As an example, my very sporadic monitoring of Moroccan press has provided some details. It used to be common wisdom that one year in six would be a drought year with major loss of agricultural output. 2007 was such a year and the Government is struggling with two major issues. High world market wheat price is pushing up the subsidies budget. Rise in the street price of bread would be a direct and immediate threat to social stability in the country. Secondly, there is a shortage of some 20% of seeds for the next agricultural season – and the season is starting right now. The shortage is of local, drought resistant varieties, traditionally held by the local small farmers.

    There was also a report on declining water resources. In the 1960’s the available water per capita was 2500 cubic meters. By 2000 the corresponding volume had declined to about 1200 m3. The Government target is to stabilize the water supply at a level of 750 m3 eventually – ways and means to be identified later.

    What next? Who knows, but it is most likely that major history for the Mediterranean has not ended yet.

    Comment by Pekka J. Kostamo — 26 Oct 2007 @ 12:30 AM

  112. Re #1 and #33: My understanding, based on an email exchange with Bill Chapman at CT, is that the Arctic sea ice anomaly should soon reduce. The arctic winter is always very long and very cold, and will probably freeze pretty much all the open water in the arctic ocean, despite the unique boundary condition of this summer’s melt. We haven’t had the rapid freezing that we usually get in October, because the arctic ocean was unusually warm. But it is cooling and will freeze before the end of the winter. So we will enter next year’s melt season with approximately a normal area of ice, but it will be thin and may not survive long.
    Of course, it all depends on weather and currents.
    I’m thinking of holding a sweepstake on this winter’s maximum ice area. I’d go for 12 million square kilometres (last winter was ~13, long-term average is ~14). Any takers?

    Comment by Nick Barnes — 26 Oct 2007 @ 9:08 AM

  113. RE 112
    Salinity also matters. Less sea ice means more storm mixing which means higher salinity of surface water which lowers the freezing point, and changes density curves. See (

    Comment by Aaron Lewis — 26 Oct 2007 @ 1:15 PM

  114. Re 113. Yes. This was something I left out for simplicity’s sake. I think it’s fairly important to say now that we’re expecting the anomaly to decrease, rapidly and soon. Otherwise when it happens we won’t hear the end of it from the deniers. Arctic sea ice has, rightly, become something of a poster child for the reality-based community.

    Comment by Nick Barnes — 27 Oct 2007 @ 5:49 AM

  115. Regarding the Southern California fires (and forest fires as they relate the AGW) it appears they served to keep the following news item more or less out of the public eye. disturbing example of more “business as usual” from the administration that says it “gets” Global Warming:


    Forest-fire warning cut from testimony

    As wildfires raged through Southern California early this week, the nation’s chief health official was prepared to tell Congress about one impact of climate change: “Forest fires are expected to increase in frequency, severity, distribution and duration.”

    But those words were never spoken. They were part of six pages of testimony deleted by White House officials before Dr. Julie Gerberding, director of the Centers for Disease Control, spoke Tuesday to the Senate Environment and Public Works Committee on the health impacts of climate change.

    See also:


    Links to the texts, drafted and edited versions. Note that the final version was 7 pages long, the draft 15 pages.

    Draft text of Dr. Gerberding, with excised material highlighted:

    Senator Boxer’s letter requesting drafts:


    It’s ironic that as we’re seeing an upswing of fires and an outbreak of so many of them in such a relatively small geographic area, the White House is determined to tell us things are not what they so obviously appear to be.

    Comment by J.S. McIntyre — 28 Oct 2007 @ 11:15 AM

  116. #103 Figen Mekik,

    Thanks for getting back. Yes I have read Shindell et al and have read a fair amount about
    the AO/NAO (Wallace/Baldwin etc etc).

    My problem is that in their “Perspectives” paper (Science March 2007) Serreze et al note
    inconclusive results of studies looking at the impact of Arctic ice loss, but conclude that
    the seasonal loss of Arctic ice will have climatic impacts. That seems to stand at odds with
    the findings of a tropo/strato source for the mode of the AO. Although a summer-free ice loss
    could affect summer northern hemisphere weather, whereas the winter AO would still have a
    predominant impact on winter NH weather.

    My main problem right now however is that I’m an amateur reader of the science, and my day-job
    has been stupidly hectic for the last few weeks. As such I’m not really able to seriously
    consider this right now. So I’ll bow out of the issue.

    #112 Nick Burnes.

    Thinner ice allows more heat flux through it, and being less mechanically strong is more easily
    disturbed by storms, creating leads that allow more latent heat flux (water vapour). I too expect
    the extent to increase this winter as always. But the loss of perennial ice itself has implications
    for the region (possibly the whole N.H. – although I can’t pin that down). Nobody should be talking
    about ice-free year round this side of ~1000ppm CO2, but a seasonally ice free state would still
    involve a yearly grown seasonal sheet in the winter.

    Comment by Cobblyworlds — 29 Oct 2007 @ 7:26 AM

  117. Re #103, that helps. Many thanks.

    Comment by Adam — 29 Oct 2007 @ 8:52 AM

  118. Could you give the full citation for the paper by Cullen and deMenocal (2000) that you reference? When I click on the link, I just get an error message from Wiley that it can’t send a cookie to my browser, and I thought I had enabled this. If I had the citation, I could get to the paper via another means. Thanks …

    [Response: I shortened the link, so it might be ok now. – gavin]

    Comment by David Garen — 29 Oct 2007 @ 12:17 PM

  119. #118. This is the full citation:
    Cullen H., and P. B. deMenocal, 2000: North Atlantic influence on Tigris–Euphrates streamflow. Int. J. Climatol, 20, 853–863.

    Comment by Figen Mekik — 29 Oct 2007 @ 1:57 PM

  120. I note from CT that the anomaly seems to have bottomed out at about -2.9 million square kilometres, and is now heading back towards more familiar territory.

    Comment by Nick Barnes — 31 Oct 2007 @ 4:26 AM

  121. Congress does science:

    Comment by J.C.H. — 31 Oct 2007 @ 12:08 PM

  122. Re 121.

    “Congress does science:”

    Oh, be still my beating heart. Anyone care to make a wager that the information content will be greater than 1%?

    Comment by Ray Ladbury — 31 Oct 2007 @ 12:49 PM

  123. “Forest-fire warning cut from testimony
    Somehow it doesn’t seem sinister that an MD’s talk about forest fires was excised! She would have to simply parrot someone else’s opinion, no?
    The fires in SOCAL are simply tribute to the stupidity of the current inhabitants thereof. Everyone wants to live in those neat canyons and on ridge tops that are simply indefensible against fires that are powered by the Santa Ana winds. CDF calls these areas WUI for Wild Urban Interfaces and has a whole list of caveats, best practices and cautions. In the 2003 fires, the losses were mostly to properties that had not complied with weed/brush control, had not removed combustible shrubs and had not built in a manner that discouraged fire spread. [Notable exception is the San Diego County areas that had been infested with pine bark beetles, leaving huge fuel loads of dead pines!] When we get to see the After Action Reports on this season, it will probably be more of the same. We can’t buy and man fire trucks for every house and we can’t lay enough pipe to provide fireflows to a hydrant in front of every house. Some of the toughest duty in the world is fighting fires driven by 50-70mph winds. It can’t be done safely without triage. In short, we have to decide what we can defend and forget about the rest.
    Yet, when we try to do controlled burns during the wet season and work small areas to reduce the fuel load, we are met on every front with obstructions. It takes from 7-13 months to get all of the approvals and the restrictions are awesome. I know many task force leaders who don’t even try. They know that if they screw up, they are history. God forgives sinners, but the CDF sure as hell doesn’t! No one wants to endanger the environment by allowing perfectly natural burns when we can control them, but they scream like hell when we won’t defend their homes against towering flames traveling 50 mph! Go figure! This is truly a situation where you pay now or really pay later! One firefighter’ opinion.

    Comment by J. L. K. — 5 Nov 2007 @ 10:12 PM

  124. Interesting article, but wouldn’t the ozone layer depletion and the increase in CO2 emission cause temperatures in the Arctic to increase more than they would close to the equator? This would then lead to a smaller temperature difference between high latitudes and subtropics, causing smaller pressure contrasts, essentially leading to less east-west winds and a smaller chance of positive NAO phases!?!

    Am I completely wrong?

    Comment by MoritzKoenig — 18 Nov 2007 @ 5:08 PM

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