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Comments 64351 to 64400:

  1. A prelude to the Arctic melting season
    Black carbon was mentioned among all the forcings discussed here. Doesn't look like much of a player. Even worse for the BC believers is Warren et al 2008: Preliminary results indicate that the snow cover in Alaska, Canada, and the Arctic Ocean has lower BC concentrations now than 20 years ago (5-10 ppb instead of 15-30 ppb), consistent with the declining trend of BC found in air samples at Alert. -- emphasis added How can a pollutant that is decreasing in concentration contribute to an increasing melt rate?
  2. The Year After McLean - A Review of 2011 Global Temperatures
    Doug H: For a purely visual guide to separating noise from signal, refer to the video on the Trend and Variation thread.
  3. The Year After McLean - A Review of 2011 Global Temperatures
    Doug H @ 20 and 24 Try Khan Academy . I suggest you google - Ted khan academy for a 20 minute video to get an understanding of the site before you try it. This should (may) be able to get you where you want to go. Also, there was a thread a few months back with suggestions, is that still available? Having a place to discuss and share info that is not directly related to a specific topic may help general readers to discuss and understand without throwing topics off. We are in the same boat Doug H, I trust sks but want to better understand the details.
  4. A prelude to the Arctic melting season
    owl@19: Read the links to studies that I provided. Thank you. Philippe: The 40% number came from a study by Schmidt-Shindell. If you don't agree with their findings, show us why they are wrong.
  5. CO2 is plant food? If only it were so simple
    There are two areas of study being developed here. 1. Established forests and the effects of CO2. 2. Short lived biota. I will have to read Rob's links concerning established forests as this is an area that I have not studied. Item 2: Higher levels of CO2 are benificial for short lived biota growth. This has been demonstrated in the links provided. Short lived biota produce the bulk of grains etc that support man's diet.
  6. A prelude to the Arctic melting season
    Enginerd, the January anomaly for much of Alaska was 20F (11C) below normal. Part of the Svalbard anomaly is global warming (see Tom's post 8) but most of the recent Svalbard anomaly was the jet stream pattern.
  7. A prelude to the Arctic melting season
    Enginerd, February 8th saw a new day record on Svalbard of 7.0 degrees C. I don't know how much above the baseline that is, but I guess it's more than 12.2 degrees C. But that's just weather. Here are the temperatures of the past 12 months compared to standard temps. Both links lead to comments made by Kris on the Arctic Sea Ice blog.
  8. Book review of Michael Mann's The Hockey Stick and the Climate Wars
    I loved the book. I just had one quibble. Mann spends some time explaining principal component analysis, which is important, as people like me know nothing about it. However, to explain it, he draws an analogy to the use of Factor a analysis in intelligence research, as described by Gould in The Mismeasure of Man. Luckily for me, I have a degree in Psychology and had read the book, so I could sort of follow along, but I still didn't understand how what Mann described was similar to reification. However, someone else reading the book may have been completely lost. There are many people who have heard of neither factor analysis nor principal component analysis, and using one to explain the other seems like an odd choice.
  9. A prelude to the Arctic melting season
    Two quick comments: 1) As the decline in Arctic sea ice continues, I'm somewhat amused by the ongoing efforts by some to downplay the significance of a warming climate as a contributing factor. Ice doesn't melt by magic. 2) I'm astounded by the temperature data for Svalbard cited in this post. Am I reading correctly that the *monthly* average temperature there is 12.2 degrees Celsius above normal? I know, it's just one month at one location, but that's an amazing observation.
  10. NASA Mission Takes Stock of Earth's Melting Land Ice
    Norman @48, you evidently do not get it. In your post 31 you referenced a document which had details for six separate aquifers, details for the aggregate of the other aquifers in the state not specifically mentioned, and details for the states total. That is eight separate sets of figures you could have chosen from. Somehow, entirely by accident according to you, you just happened to choose the figures with the lowest recharge rate relative to withdrawals. Not only that, you managed to choose the figures with a ration of withdrawals to recharge that was 8.9 times higher than the ratio for the total for the state, and 10.9 times greater than for any other single aquifer. And you managed, quite by accident apparently, to choose the only aquifer with a ratio that suggested the issue of recharge was trivial, and could be neglected. And indeed, you then continued to neglect it in following posts, persistently. Consequently, your explanation does not wash. You were cherry picking. And saying you were not does not make it so. Given this episode, and Norman's apparent inability to understand basic integrity in data reporting, reader would be well advised to ignore anything he has to offer in future, for it will not be based on a full examination of the evidence, but only on that evidence which suites whichever case he is making.
  11. CO2 is plant food? If only it were so simple
    layzej @93, I appreciate that you think I am more nuanced, but on this topic Rob Painting is certainly better informed than I am, and I suspect also than John N-G is. He has certainly found some research which counters John N-G on the short term impacts of CO2 rise along with global warming on land plants. My point has been that John N-G was not justified in his criticisms of the blog post above. Indeed, it is not even relevant in that it missed the point of the post, which does not discuss time frames per se. On the other hand his point may be relevant regarding Rob's prospective three part blog (which I am looking forward to). I doubt, however, that it will be justified.
  12. CO2 is plant food? If only it were so simple
    Of the three positions, I'm inclined to trust Tom Curtis, whose position seems more nuanced, over Rob Painting or John Nielson-Gammon. I'll use IPCC AR5 as the final arbiter. It would be ironic if JNG ends up failing his own litmus test ;)
  13. A prelude to the Arctic melting season
    The weather has turned in the Barents and Kara regions. In the coming 2-3 weeks we'll see how much of the ice returns. Of course, it will be much thinner than usual. I've also just published a short piece on the situation in the Bering Sea, where ice cover is anomalously high for the time of year. We'll start discussing the Northwest Passage, once it starts opening up completely in August, just like in the last 5 years. Or was it 6 years? I've lost count... ;-)
  14. NASA Mission Takes Stock of Earth's Melting Land Ice
    Tom Curtis @34 My point is off topic for this thread so I will quit but before ending you ask me to apologize and blame me for "cherry picking". In the 31 post you refer to I was not "cherry picking" the worst recharge rate to form a global conclusion or even support my original post of 21. It was a side point directed at you to show the difference in aquifiers. Some recharge quickly, others not so quickly. It was a side point only and its use was as a demonstration of difference. I did include Global amounts in other posts. So I can apologize for a misunderstanding in what the post's objective was. Does that help? The 8.93 to 1 figure was in a post 33 to KR. I was contrasting his paper with others that indicate the amount of water released form water mining is much greater than what this study showed. In your final post of 47 you would seem to support my assertion that KR's report has greatly undereported how much water is being removed from underwater storage. You have the point withdrawl is only 5% of recharge rate. Sounds small but look at the number you posted 734 km^3/year. This is more than the 545 km^3 I used to show 8.9:1 vs KR's paper. The 545 was just water used for irrigation, other uses have made the number larger to 734 km^3/year. Does this explanation help? My posts may be in direct response to someone's post and not be part of an overall (which is what post 31 to you was about).
  15. Northwest passage has been navigated in the past
    Camburn, I have never called into question the skills of Capt. Larsen (in fact I praise him and his crew), but his own words (as given above) speak volumes : ...“It was really the only fine day we had during the entire passage...” (2) “...season was the worst in years.” (1) (2) Read the references given if you can.
  16. CO2 is plant food? If only it were so simple
    Thanks all! It will be interesting to see where the IPCC AR5 (with newer studies considered) will fall on this issue.
  17. Dikran Marsupial at 21:21 PM on 12 February 2012
    The Year After McLean - A Review of 2011 Global Temperatures
    Minor note: If Santer at al. investigate the amount of data needed to detect a trend of 2 degrees per century and get 17 years, if the trend is less than that then a longer timescale will be needed to reliably detect it.
  18. The Year After McLean - A Review of 2011 Global Temperatures
    KR and Bernard J, thank you both for your contributions. I revisited the 'Separating Signal and Noise' page KR linked and appreciate the information (and the comments afterward). My difficulty is that I don't have the math to follow the arguments very far. It is frustrating to be intensely interested in the topic and be unable to dig deeper into it. I judge the expert advice on this site to be sound, but that is not the same as being able to work it out for myself. Can I have my life all over again please? I promise to try harder next time ...
  19. A prelude to the Arctic melting season
    Beaufort Gyre link: http://www.whoi.edu/page.do?pid=66296 the 'flywheel' of the NH ocean current system may change direction leading to changes elsewhere, but how many 'gears' does the system have? one could assume there are several potentially stable energy levels between the various water masses, but does the potential disappearance of summer ice change the entire system even in winter?
  20. Volcanic Influence on the Little Ice Age
    Thanks muoncounter -- SkS articles are fantastic and I always learn from the comments too.
  21. The Year After McLean - A Review of 2011 Global Temperatures
    And Doug H, I feel your pain. Often even the simplest answers appear to be so only in hindsight, and the answers to those questions above don't immediately jump out for many people - sometimes even for people are supposed to understand statistics! Of course, the whole underlying issue completely sails over the heads of the Denialati, no matter how many times it's explained to them - and it's been explained to them repeatedly. When Bolt commented on the Santer et al paper he thought that it meant that because it required 17 years of data to detect statistically significant warming rather than 10 years (according to the paper of Santer et al), it meant that scientists wouldn't know until 2018 (2011 + 7 more years) if the planet was warming. That's either very stupid mind, or a very ignorant mind, or a very mendacious one - or some permutation of any or all of the preceding. And Girma Orssengo certainly didn't ever figure it out - if you read the Matthew England thread you'll see that his answer, when it eventually came, is completely and utterly clueless.
  22. The Year After McLean - A Review of 2011 Global Temperatures
    Doug H. There are simple ways and there are more complicated ways to derive answers to those questions. KR has already directed you to Santer's et al work, and Foster and Rahmstorf consider the problem too. There's an abridged version of the latter at Open Mind, but remember that this analysis removed the influence of exogenous factors such as ENSO, where Santer et al didn't. Thus, Santer's minimum-required time period for statistical significance is a little longer.
  23. A prelude to the Arctic melting season
    From Camburn #17: "1. There seems to be a solar influence concerning Arctic Ice flucuations." The opposite - ice-extent reductions have increased sharply in a period that the pro-pollutionists raved and ranted was dominated by low solar activity. "2. Black Carbon, an anthorgenoponic emission, is also responsable for the current decline in ice." Sure, ABC shows up for a serious influence in this decade - that's the current picture. But the Warsaw Pact Cloud didn't have the same effect in the 70s/80s. And the clear decade of the 90s didn't produce a recovery. "3. Increased temperature is also responsable for the decline in Arctic Ice." Very true, except for the weak phrase "is also". The places to start with understanding the disruption of the Arctic ecosystem is heat conveyers - through the winds, via ocean currents north, and from freshwater runoff into the Arctic Ocean. As for the St. Roch reference - it is anecdotal. There's no metric, no baseline comparison ... it's just an amusing arctic-summer observation.
  24. NASA Mission Takes Stock of Earth's Melting Land Ice
    Norman @39, you say I provided a good challenge, and then you do not take it up. The challenge was to show both global figures for groundwater recharge and withdrawals. You point to a paper which provides both of those figures, but you only discuss the differential in basins in which withdrawal exceeds recharge. For what it is worth, the paper you link to estimates a global recharge rate of 15,200 km^3 per annum, and a withdrawal (abstraction) rate of 734 km^3 per annum. So withdrawal is only 5% of recharge globally, according to this paper. So, despite your continued cherry picking of the data, you have still not shown evidence that supports your claims, let alone establishes them. If you wish to discuss the depletion rates of aquifers used for irrigation, than regional data confined to those parts of the Earth suffering from depletion is relevant, but your entire discussion is then off topic in this thread. If we want to discuss the effect of the global water balance for aquifers on sea levels, then discuss the global effects, and stop this transparent cherry picking. Finally, I notice that you have neither explained nor apologized for your blatant cherry picking as detailed at 34 above. In view of this there is no point in further conversation with you until you do. Somebody capable of unapologetic cherry picking in so blatant a manner is not interested in rational conversation, or in finding the truth of things. They are only interested in deceiving people with half truths. Such people should be exposed, not debated with, and your continued cherry picking has certainly exposed your intentions.
  25. NASA Mission Takes Stock of Earth's Melting Land Ice
    Agnostic - in regard to the Asian High Mountains - 2010-2011 saw hundreds of billions of tons extra snowfall. If the study had not included those years it would have shown a dramatic loss of ice. What it shows is that, rather than being stable, as erroneously reported elsewhere, even the high plateau is warm enough to sheds lots of ice annually. Are they likely to get such snowfalls in the future? There are decades of warming yet to come, how will that affect the region?
  26. NASA Mission Takes Stock of Earth's Melting Land Ice
    GRACE provides a good indication of the magnitude and area of ice loss but, because it has difficulty in detecting smaller areas where loss is occurring, it should be regarded as providing an understatement of land ice loss. For example, physical inspection shows that glaciers of the Sierra Nevada are in retreat. Similarly glaciers in Glacier National Park are mostly in retreat, yet neither of these is detected by GRACE - or are they detected but the data is not used to show these losses? The reason I ask is because 2009 data provided by GRACE did show depletion of groundwater in the Central Valley of California over a 6 year period but now it purportedly shows nothing – or at least nothing it reported in respect of this area. Nor is anything reported on the state of glaciers in the numerous Russian mountain ranges, thought many are known to be in retreat. GRACE detects gravity changes arising from the movement of water whether in the form of ice, snow or liquid. If glacier ice melts in the Himalaya mountains and is stored as natural lakes, then GRACE will show no loss since there has been no change in gravity. GRACE can not measure the different forms water is present in an area, only the extent to which it has moved into or out of that area. Rob Painting makes the valid point that … “under conditions, such as the recent La Nina-dominant period … a much warmer western tropical Pacific intensifies the Asian Monsoon, and dumps more snow on the high plateau.” This does not appear to have occurred during the reporting period, though it may have occurred more recently. Had it done so, GRACE would have recorded the resulting change in gravity – unless of course increased precipitation was largely balanced by loss of water from the region. What is clear is that if GRACE shows net loss of 500 gigatonnes/annum, there is only one place most of it has gone – the oceans. It puts me in mind of James Hansens prediction of decadal doubling in the rate land ice loss throughout this century. Anyone who thinks that will have no effect on RSL needs to give cogent reasons for their thinking.
  27. CO2 is plant food? If only it were so simple
    layzej @87 - Well, I'll just stick to the CO2 fertilization effect, and ignore all that utterly dire stuff about ocean acidification then. First up let's be clear, the argument that John Nielsen-Gammon makes is that extra CO2 will be beneficial in the next few decades. To test that we need to look at what the observations reveal. Again, I point out that we (SkS) don't dispute that CO2 fertilization is a real phenomenon, but the point is, will this effect be enough to counter the negative effects of a warmer and perhaps drier (for many regions) world? We know that the carbon cycle models used in the last IPCC assessment report expect this CO2 fertilization effect to be huge in the 21st century. Those models simulate a dramatic draw-down of atmospheric CO2 by land vegetation. But they also assume no nutrient limitation - which seems a glaring omission. - no evidence of CO2 fertilization leading to increased biomass in a Thai tropical forest: - Long-term increases in intrinsic water-use efficiency do not lead to increased stem growth in a tropical monsoon forest in western Thailand - Nock (2011) - no CO2 fertilization net benefit in a Costa Rican rainforest - Annual wood production in a tropical rain forest in NE Costa Rica linked to climatic variation but not to increasing CO2 - Clark (2010) - no CO2 fertilization net benefit in a Canadian forest - Testing for a CO2 fertilization effect on growth of Canadian boreal forests - Girardin (2011) - and crucially, no global CO2 fertilization effect net benefit in the last 40 years - increased water-use efficiency during the 20th century did not translate into enhanced tree growth - Peñuelas (2011) they write: "Location A global range of sites covering all major forest biome types. Main conclusions These results show that despite an increase in atmospheric CO2 concentrations of over 50 p.p.m. and a 20.5% increase in iWUE (intrinsic water-use efficiency) during the last 40 years, tree growth has not increased as expected, suggesting that other factors have overridden the potential growth benefits of a CO2-rich world in many sites. Such factors could include climate change (particularly drought), nutrient limitation and/or physiological long-term acclimation to elevated CO2. Hence, the rate of biomass carbon sequestration in tropical, arid, mediterranean, wet temperate and boreal ecosystems may not increase with increasing atmospheric CO2 concentrations as is often implied by biospheric models and short-term elevated CO2 experiments." And the real clincher is that the tropical regions, despite the huge deforestation occurring there, are actually by far the largest land-based carbon sink, and they happen to be the most threatened, because tropical trees most likely exist near a thermal tolerance threshold. This meme by John NG is extremely disappointing coming from a climate scientist who should know better. But to adequately de-bunk it (yes, there is a great deal more peer-reviewed science to debunk it) requires perhaps a two or three-part blog post/rebuttal. I've added it to my to-do list.
  28. Monckton Myth #17: Debate vs. Denniss, Part 1
    ..quickly, let me apologize for the grammatical and spelling mistakes in the earlier comments. I think one can make out what I intended to say, but they are a bit annoying to read. Also, the part contrasting measurement+observations against just modeling was way drawn out and a little inconsistent as worded. ..Whatever.
  29. Climate change policy: Oil's tipping point has passed
    Sphaerica@68: I don't know why anyone needs to drive a tank for mundane tasks. And I sure don't know why anyone would drive to get one loaf of bread. I also have a hard time with that....as we make our own bread, have our own garden, etc. 2. I am very concerned with ocean PH. I think that is the largest downside risk to higher levels of CO2. That is also the most demonstrateable risk....it just can't be ignored. 3. Temperature records are a very poor metric to use concerning climate. A desert can have a temp of 110F and have less heat content of the air than a Mississippi swamp at 75F and 90%SH. I have always maintained...forget temperature, it doesn't demonstrate anything. Even the "Texas Heatwave" of last year had less heat content than the normal climate there because the air was dry. 4. Mediation: a. I have been a staunch supporter of nuclear for over 30 years. I find it senseless that we have NOT invested and directed investment to this precious resource. b. Solar is great where practical and competitive. In North Dakota, USA, it will never work. c. North Dakota has wind. However, there are drawbacks to wind which I am learning. I live approx 14 miles from an approx 180MEG wind farm. Through my co-op, I own part of it. It is not working out very well, unfortunately. And when the geese get done flying through it, makes me sick......so I have become not too keen on wind anymore. I don't think anyone denies climate change, as the evidence of climate change is certain. Where you will find the arguement is the sensativity of climate to CO2, and that is very debateable. You will also see folks deny the effects of the sun who are ardent AGW supporters. That should never happen, but I read it all the time. There is too much literature out there showing hydrological effects from sun variations over wide drainage areas. This gets back to clouds and sun. There is an established relationship there that can not be denied as it is evident in drainage basin studies. From a moral perspective, FF should be saved as much as possible. Plastics, high HP needs etc are well met by FF. They really do enhance our lives. How do we achieve reductions in FF use? 1. Educate people without the constant "fear" factor. 2. Stop government meddling. Remember, the light bulb, the telephone, so many things that we use daily were invented by private industry. That industry did not have to worry about a government funded institution owning the pattent. 3. Get fed/state/local spending under control so that people, at least in the USA, have the resources to make "smart" decissions. The current projections show that an economic breakdown is only a few years away, which will completely hault an orderly transition. Just a few ideas. Moderator: I looked for a different thread as this has moved a bit off topic and didn't find one. I don't want to get banned again as I feel I have a perspective to offer this forum that at times I feel it lacks. Please delete my note to you before allowing this to be posted or delete the post at our discretion. Thank you.
  30. CO2 is plant food? If only it were so simple
    Layzej @80, the time frame considered in the response is just the next century, and as such is determined by "skeptical argument" it is rebutting. Where the so-called skeptics nuanced enough to argue that in the sort term, net benefit to agriculture from global warming is positive, but in the medium term it is uncertain, and in the long term under BAU it will be significantly negative in most areas, and negative overall globally, I'm sure the response would have discussed the different effects over different time periods - and largely agreed with them. I'll also note that had the myth it is rebutting been more geographically nuance, I'm sure some of the geographical nuances would also been reported. One of those is the fact Camburn is benefiting from, ie, that the Northern USA and Canada will probably get higher yields for some time to come (possibly for the next century even with BAU). Unfortunately their good fortune in that respect does not generalize to the rest of the world.
  31. Philippe Chantreau at 14:56 PM on 12 February 2012
    A prelude to the Arctic melting season
    Camburn, B.S. Anecdote, per Webster dictionary: "a short account of an interesting, often biographical incident." Any biographical incident has little bearing to the bigger picture. It is an individual occurrence. The St Roch's account is no more telling than the swim over the pole. How long did it take to cross the Northwest passage back in these days? 3 years. Recently, it was done by a small sailboat in a few weeks. This argument is so ridiculous I don't know why anyone would even put it forth. As much as 40% due to black carbon. That leaves 60% or more (could be much more) to other factors. Gee, I feel so much better knowing that. Looking back at your history here it seems you have no more to say than you ever had before.
  32. Climate change policy: Oil's tipping point has passed
    67, Camburn, Then with limited fossil fuel resources that is all the more reason to preserve those reserves for the situations where it is difficult to find other power sources (e.g. high HP and jet fuel). So why do we squander it by driving SUV's with one person in them to the store to buy one loaf of bread? Why do we use fossil fuel to generate electricity for light and power in homes and buildings? Why does our entire power infrastructure revolve around fossil fuels with no visible effort to make the necessary transition? We have three hugely compelling reasons to stop this: 1) FF are a limited resource which will cause economic upheaval when they begin to run short (and many say that time has arrived, as the above post explains). 2) FF are generating greenhouse gases which will inevitably cause economic, behavioral and physical harm, for which the only solution will come from a new, viable power source that not only replaces fossil fuels but also would provide the accompanying energy that will be required to adapt to climate change. 3) FF are dramatically changing the pH of the oceans, which will result in a lack of food availability in the greatest farm this planet knows (the oceans)... and the chances of finding a viable solution to that growing problem, no matter what power source is discovered, is virtually zero, so every day's delay is another step towards disaster. So why do people continue to find every reason they can to deny climate change, ocean acidification, and the inevitable economic downside of a fossil fuel economy, when a three-barreled gun is staring us in the face?
  33. NASA Mission Takes Stock of Earth's Melting Land Ice
    Norman - There are two separate conversations going on here, and a certain lack of recognition of that issue. First: Deep aquifers are being depleted at high rates in many ares. This is definitely bad - leading to numerous agricultural issues and relocation costs. Current practices will not be sustainable in many areas. But the best data available indicates that a roughly equivalent amount of water is being sequestered elsewhere, changing the current availability of said water in considerable detail without affecting total runoff. While I don't want to minimize this very important issue, it's not the center of this thread. This thread is on the climate change effects on the cryosphere, on ice melt in areas >100km^2 as measured by GRACE. It is very useful, however, that the GRACE data also supplies some information about aquifer changes. Second: Sea level rise due to anthropogenic is not greatly affected by terrestrial/anthropogenic usage. Milly et al 2010 shows that in considerable detail (with numerous reference of their own). --- So: Aquifer level changes, recharge rates, etc. - all of those are off topic here. Assertions that anthro water usage affect sea level are not supported by the full set of data, your cherry-picking of single numbers from Milly 2010 notwithstanding. Moderators - Perhaps side topics such as aquifer changes need to go elsewhere?
  34. Philippe Chantreau at 14:34 PM on 12 February 2012
    CO2 is plant food? If only it were so simple
    Camburn, "it is established" requires real substantiation, put up the references. This statement leaves a lot to be desired: "By having larger root balls/mass the plant has a larger structure to overcome normal potential weather variations." Provide references to studies showing that it actually does allow them to overcome. Without it, this is nothing but wishful thinking. When they were trying to break the sound barrier, engineers though that a generously reinforced structure would enable a onventional airplane to go there and back safely. It wasn't quite so. If you're so worried about going broke you need to adress the factors that make prices so volatile. They belong with the banks and the speculators trying to profit from commodities markets, good luck going after that. I live in the 40's latitudes too and I was battling mosquitoes on my outing to the falls today with the kids. Never seen them yet in this place at this time of the year. If you are in a place that already was on a Northern margin, then probably you're safe, and warmth in your area is indeed beneficial. I'm sure the ones who live closer to the Southern margin have a different take. Of course, if we stick purely to the capitalistic risk/benefit analysis, in your individual case you're not supposed to personally give a dam* about the problems of farmers who live in other places. In fact, the more they suffer, the better you're likely to make out: production decreased on their part, increased on yours, if the overall production is down, you'll really make a killing without having to do anything special. More power to you I guess.
  35. A prelude to the Arctic melting season
    As presented above: 1. There seems to be a solar influence concerning Arctic Ice flucuations. 2. Black Carbon, an anthorgenoponic emission, is also responsable for the current decline in ice. 3. Increased temperature is also responsable for the decline in Arctic Ice. The loss of Arctic Ice is a multifaceted issue.
  36. NASA Mission Takes Stock of Earth's Melting Land Ice
    KR and Tom Curtis Here is another report which gives even a higher figure for unsustainable water use (being withdrawn at higher rates than replenished meaning it will increase the surface amount by that volume since it is no longer present in the location it had been). Fresh Water Chapter 7. In this book you can scroll down to page 175 and view Table 7.4 In this table they give the World non-sustainable water use. Ranges from 391-830 km^3/year (Note Tom Curtis, even replenishable aquifiers can be pumped at rates exceeding their recharge rates). If you use the highest value for non-sustainable water use it would be a very significant player in SLR. (830/61=13.6)....(13.6 x 0.17 mm SLR for 61 km^3 H2O=2.31 mm). Current SLR rate is 3.4 mm/year so this water use could account for over 50% of the current rate of SLR if the higher figure is used. I am not saying this would be valid. I brought it up to make a point that you should not discount water mining as one possible source of SLR, it may be larger than you currently accept.
  37. A prelude to the Arctic melting season
    Philippe: The observation from the Captains log are not anecdotal. They are reported observations. Observations are 1st hand, anecdotal are 2nd hand. The following paper from DMI is worthy of consideration to explore all avenues that affect Arctic Ice. It has been established that "Black Carbon" may be responsable for 40% of the current temp/melt. Ref link to Schmidt/Shindell posted above. DMI East Greenland Ice
  38. NASA Mission Takes Stock of Earth's Melting Land Ice
    Norman@41: AT the rate of depletion of fixed aquifiers, the problem will come to an end in approx 18 years based on the latest information I read. Not a very comforting thought at all.
  39. NASA Mission Takes Stock of Earth's Melting Land Ice
    KR @35 Your link does state that ground water mining will result in a positive increase in SLR of 0.25 mm/year. My problem is with the huge difference in calculating the amount of unsustainable water removal from deep aquifiers. The listed total amount of deep water used in irrigation is 545 km^3 per year. As Tom Curtis pointed out, this amount does not indicate a recharge rate of even the deep water wells. I did find another source that points out that of this amount above, 234 km^3 (in the year 2000) is unsustainable meaning it is not going back into the deep aquafier storage but being removed and added to the total surface water amount. Section 8.4.3 in your linked article are what I question. How are their numbers so much lower than other sited sources? If you use the other value of 234 km^3(which was a 2000 number and may be higher today with expansion of deep water mining) instead of 61 km^3/year that your link uses, the amount of SLR due to deep water mining of fossil aquifiers is closer to 1/5 of the total amount and is a valid player in the SLR equation.
  40. Climate change policy: Oil's tipping point has passed
    Sphaerica: I was talking about large HP needs. When it comes to cars, I am 100% behind you. I have a couple of friends that have a hybrid. Yes, in winter they don't work too well, but for 70% of the year, they work very well. My next car purchase will be a hybrid. I have a hard time understanding why anyone wouldn't buy a hybrid for transportation needs of a few people. And the costs are not high in comparison to many alternatives. The practicality when it comes to large HP needs tho is that many times the large HP needs don't shut off for days and pontentially weeks at a time. There is no time to recharge, and the price of having batteries large enough to supply the power over extended periods of time just does not compute.
  41. Philippe Chantreau at 14:11 PM on 12 February 2012
    A prelude to the Arctic melting season
    Camburn, how am I supposed to be impressed in any way by a record reporting no ice in sight in late August and September? In the anecdotal area, do you remember about the guy who was swimming in open water at the North pole a couple of years ago? Shall we put this up in the anecdote contest? Please... This anectodal record is of very little interest. This winter ice area and extent are low so far. We'll see how it turns out in late September, which is the metric that matters the most. I note that the January extent is so exactly on the linear regression of the overall decline of the month' extent that it's almost as if the ice had been rehearsing. I find the ice area graph at Cryosphere today even more concerning, it's showing the same pattern as last year, but 250k sq. Km lower. In any case, we're nowhere near the 1979-2000 average, in either metric.
  42. CO2 is plant food? If only it were so simple
    Sphaerica@86: 1. It is established that cereal plants respond well to increased CO2. 2. It has also been established by root studies that plants develop larger root mass with the presence of CO2. 3. By having larger root balls/mass the plant has a larger structure to overcome normal potential weather variations. 4. You indicate more volatile precip and temperature patterns. I don't know if you can get much more volatile than the climate I live in. An old saying in the upper plains of the USA is "If you don't like the weather right now, wait 5 mins and it will change." The higher levels of CO2 that increase plant mass that I have read are up to approx 850ppmv. What happens after that, I don't know. The studies done by the Ag community reflect the potential levels that "may" be obtained. The element of risk in production ag is so large, that a small addition of a potential benifit is viewed positively. The upper plains of the USA, and I live very near the 49th parallal. One of the areas that is suppose to be most affected by climate change. At this point and time, there has not been any variation from the long term norms of just right, to too wet, to too dry. From too cold, frost in 2005 in August, to to warm.....that hasn't happened since 1988. I read studies of anything pertaining to production ag with a very critical mind. A small change can be the difference between being profitable, and going broke. And worst of all, not having a crop, as my desire is to feed people. Warmth in my area is benificial to production as most of the time we are on the edge of being too cold. Precip patterns are within the boundaries of a 80 year wet/dry cycle in the Central Corridor of the USA that is part of a longer 400 year cycle: 400 year cycle of precipitation of Great Plains of NA Shorter cycle within the longer cycle:
  43. Global Sea Level Rise: Pothole To Speed Bump?
    Hansen, in a 2005 editorial essay cited Kienast et.al.2003 and said "In melt-water pulse 1A... sea level rose about 20m in approximately 400 years" which "is an average of 1m of sea level rise every 20 years". Which is about 0.14 mm per day. This would be a catastrophic rate for people living near the sea. He noted that the ice sheets disintegrating at the time "were at lower latitudes than the ice that remains today and the period of rapid ice sheet disintegration was undoubtedly preceded by a period in which the ice was preconditioned for collapse". But, he points out climate forcing today far exceeds the forcing that drove melt-water pulse 1A. And, he said, sea level rise doesn't have to add up to 20 m to obligate scientists who expect it to happen to warn that an event anything like it would "wreak havoc" on civilization. Hansen has said in the past that if the planetary energy imbalance is about 1 W/m2 and all that energy was going into melting ice it would raise sea level by about 1 m per decade. Obviously, an armada of icebergs shooting off Antarctica wouldn't have to melt to raise sea level. Pfeffer told a story at the AGU this year about how the sea level rise threat isn't being fully grasped even by those he would have thought must be exposed enough to the data to get it. He said MOMA in NYC exhibited a model showing a New York that by 2100 had protected itself from 2m of sea level rise. He asked the designers, what was the plan for the ongoing steady or possibly accelerating rise after that - how was their design going to cope with another meter and another one after that? Blank stare.
  44. CO2 is plant food? If only it were so simple
    muoncounter @77, Fact 1 and 2 are off topic on this thread and moreover not areas where JNG has suggested that SkS has fallen down. Michael sweet @78, I'm not sure what you are getting at. The JNG post was written after considering this very SkS post and finding it wanting. Rob @79, No doubt there are many reasons to reduce CO2, however JNG has suggested that this particular item is a litmus test to determine whether the person you are listening to is honest and knowledgeable. A bold statement and one that I am grateful to see addressed by you and the S(k!)S team. Tom Curtis @80, thanks for the thoughtful and thorough response! Your points are all well taken, although I'm not sure it's a good idea to consider policy turn around time when writing a post. I would like to think of SkS as a place that cuts through all the BS and provides the facts - warts and all.
    Moderator Response: [JH] The auditions for SkS Moderator candidates were held last week.
  45. NASA Mission Takes Stock of Earth's Melting Land Ice
  46. NASA Mission Takes Stock of Earth's Melting Land Ice
    Tom @34 You provide a good challenge "Note that I do not know the recharge rates. Globally they may also be trivial. But you need to either cite them to establish that, or to cite a peer reviewed source to that effect." I did some research into this and found this Nonsustainable grounwater sustaining irrigation: a global assessment. I did sight the 545 km^3 from deep water mining from the other link. I have not found a correct current amount of nonsustainable water mining (fossil aquifiers) so I am not sure what it is in 2012. In 2000 it was found to be 234 km^3 (from the link above). From the abstract: "Results also show that globally, this contribution more than tripled from 75 to 234 km3 yr−1 over the period 1960–2000." Nonsustainable water mining tripled from 1960 to 2000. In 2000 it was estimated to be 234 km^3/year. In 2012 if may be higher than 2000 but probably not as high as the 545 km^3 given in the other article. Nonsustainable means the this water is being removed and not replenished. Here is the general description of aquifier types: "There are two types of aquifers: replenishable and nonreplenishable (or fossil) aquifers. Most of the aquifers in India and the shallow aquifer under the North China Plain are replenishable. When these are depleted, the maximum rate of pumping is automatically reduced to the rate of recharge. For fossil aquifers—such as the vast U.S. Ogallala aquifer, the deep aquifer under the North China Plain, or the Saudi aquifer—depletion brings pumping to an end. Farmers who lose their irrigation water have the option of returning to lower-yield dryland farming if rainfall permits. In more arid regions, however, such as in the southwestern United States or the Middle East, the loss of irrigation water means the end of agriculture." source. Here is another describing fossil water water 75,000 years old in Libyan aquifier.
  47. A prelude to the Arctic melting season
    skywatch#9: Polyak 2010 was discussed here. analysis of several hundred indicators of past Arctic sea ice extent tells us that recent losses appear to have no parallel in records going back many thousands of years (Polyak et al).
  48. Climate change policy: Oil's tipping point has passed
    60, Camburn,
    Note the "at present there are no economic alternatives."
    Bullsh*t. There are no "economic alternatives" because we continue to invest more and more in the existing infrastructure and comparatively ignore other "uneconomical" potentialities. We keep things that way with our behaviors. Hybrid cars have been feasible and economical for a decade. Only the lack of true massive-scale production keeps their costs high. Our dependence on a rickety and failing fossil fuel infrastructure is primarily hampered by our continued investment in that same, dead-end infrastructure. The denial crowd has done a wonderful job of keeping the lack of "economic alternatives" a reality, and on our current course they will continue to do so for several decades until (as you say) the necessary transition comes with a cultural and economic shock. It stuns me that you are unable to see this or, despite your own admission of the problem, to use your foresight to move past it.
  49. CO2 is plant food? If only it were so simple
    85, Camburn,
    The types of plants that feed the world have repeatedly demonstrated increased productivity from higher levels of CO2.
    Do they similarly react well to increased temperatures, increased or decreased moisture, and more volatile precipitation and temperature patterns? Do they demonstrate an unending improvement for higher and higher levels of CO2, without limit or eventual negative result? Are you in a business where you can afford to simplistically look at and focus on a single variable, with complete disregard for other factors?
  50. CO2 is plant food? If only it were so simple
    Tom@83: I am in production agriculture Tom. The "quarter" I am most interested in is feeding people. As most of the worlds food stocks are annual in nature and derived from grasses, the area of research most intersting is the responses to co2, etc. The types of plants that feed the world have repeatedly demonstrated increased productivity from higher levels of CO2. Rob@84: I will have to re-read Lobell (2011). There were problems with that study that a farm paper talked about. When I have time to read it and reference it, I will comment on said link. Thank you for the Link.

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