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Comments 110151 to 110200:

  1. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    From von Shuckmann et al. (2009, JGR-Oceans), rate of change of 0-2000 m heating storage +0.77 W m-2 between 2003 and 2008. Hansen et al. (2005) reported a planetary heating rate of +0.85 W m-2. Von Shuckmann et al. can be found at: http://www.agu.org/journals/ABS/2009/2008JC005237.shtml Von Shuckmann et al. (2009) state that: "Global mean heat content and steric height changes are clearly associated with a positive trend during the 6 years of measurements." Hadley and PMEL show a slight increase in 0-700 m OHC after 2004. Now OHC for 0-700 m from Josh Willis show otherwise, while global SLR data show no slowdown. So much uncertainty. Yet some insist on publicly making unequivocal (and misleading) statements that global warming has halted after 2004, such statements are like fodder for the "skeptics" and those in denial about AGW. Scientists have a responsibility to clearly report the facts, which includes stating caveats and uncertainties in the data and analysis.
  2. actually thoughtful at 02:21 AM on 14 September 2010
    The contradictory nature of global warming skepticism
    Baz Skepticsim does not equal "I doubt." Nothing you have posted indicates you have earned the title of skepticism - approaching the world with a "let's see the facts" attitude. Instead you express your (personal, unfounded in facts) doubt selectively, and yet you are gullible in regards to anti-science (not being harsh - AGW IS the science of climate) claims. Thus you buy into "no warming since (pick a recent year)" but refuse to seriously consider trends over 15-20 years. You ignore sea level data, but are a fan of ARGO based OHC numbers. You ignore satellite data, temperature data, ice volume data, sea acidification data and the slam-dunk - night time warming data. Help me out - can you put your position into a internally-consistent theory or thesis? It is 2010 and I claim that "I doubt" is no longer a valid counter to the science of our climate (aka AGW).
  3. The contradictory nature of global warming skepticism
    Eric #102, I responded to your comments on polar bear hunting here. Basically, I think the data shows this to be a red herring.
  4. European reanalysis of temperature confirms record warmth in 2010
    Hi HR, Thanks, yes I got lucky there with my back-of-the-envelope estimate for the trend. Yes, they are fused, you can compare their data online using an interactive plotting too. What is interesting is that the ERA-40 seems to have been slightly warmer than the newer ERA-interim, which is anything would have reduced the warming trend. I cannot speak to how they spliced the data together, you would have to chat to them about that.
  5. Polar bear numbers are increasing
    Eric, actually they use "removal" and "harvest"... if you really think that is "obfuscation" then I'd say you place entirely too much weight on semantics. In any case, the claim that hunting is the most significant problem are simply insupportable from the data. Even setting aside the fact hunting quotas can be (and ARE) adjusted as their impact is determined and thus have no long term significance... the majority of population decline is attributed to sea ice loss. For example, the large Davis strait sub-population has an estimate of sustainable kills per year of 66 bears... and 60 bears average actually taken over the past 5 years. Yet the population is in decline, because sea ice conditions have deteriorated. Ditto for the Southern Beaufort sea and Western Hudson Bay groups. Likewise Southern Hudson Bay is currently stable, but the bears have begun to lose body mass due to loss of sea ice (just as observed in other areas prior to population declines) and thus are projected to decline in the future. Over hunting is a temporary problem correctable by adjusting quotas (which is done all the time) and which is only impacting a small percentage of bears. Sea ice loss is a long term problem with no known solution that is threatening several of the largest sub-populations with being wiped out entirely.
  6. European reanalysis of temperature confirms record warmth in 2010
    17.Albatross The graphs in this article are actually data from ERA-40 and ERA-Interim fused together. Which seems strange? You can get the data for each of those from the link in #17. The trend for ERA-Interim (1989-2010) is 0.168 C/decade. Good guess!
  7. The contradictory nature of global warming skepticism
    Baz, I'd second Riccardo and Ann above, but also, as I did the work for you I'd appreciate more than just a "that's fair enough" response. Could you let us know whether you agree with the analysis, and if not, why not, providing your own working. Fair enough ?
  8. Why positive feedback doesn't necessarily lead to runaway warming
    Nice job Neal! All levels are excellent.
  9. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    GPWayne, When (and where) exactly in 2008 did Pielke Snr say this? "Global warming, as diagnosed by upper ocean heat content has not been occurring since 2004” Thanks.
  10. The contradictory nature of global warming skepticism
    Baz @98, I too will warm you of the pitfalls about drawing conclusions based on short windows. Oh, and the there is another contradiction made by "skeptics", I thought the CRU data was "corrupted" after (faulty) claims where made after the stolen emails were posted. But now skeptics seem to gravitate towards HadCRUT because it shows the least/slowest warming of all the global SAT products (mostly b/c it excludes the Arctic where we know rapid long-term warming is taking place). Hansen has written on the global SAT and he says, with good reason, that using a running average of SATs is a better way to depict the global SATs (it effectively reduces the noise). Baz, have a look at the NASA GISS graph below and tell me that you think global warming has stopped: Also, consider reading this If time is an issue just look at Fig. 21.
  11. European reanalysis of temperature confirms record warmth in 2010
    11.michael sweet You can investigate the ERA-Interim reanalysis using this tool. http://climexp.knmi.nl/selectfield_rea.cgi?someone@somewhere It shows for NH winter (DJF) that, as you say, NH mid-latitudes (30N-60N) were below normal. But actually quite cold, -0.4oC below average. SH mid-latitudes were fairly ordinary, +0.1oC. The two polar regions and the tropics were hot at +0.4oC to +0.6oC above average.
  12. Why positive feedback doesn't necessarily lead to runaway warming
    In a first for Skeptical Science, Neal actually wrote all 3 levels of this rebuttal in one fell swoop. Nice work, Neal. Congratulations on being the first one to accomplish this! It will be interesting to see how different people are able to make use of the basic, intermediate, and advanced versions.
  13. The contradictory nature of global warming skepticism
    @Eric: sorry, I didn't realize the Norwegian group was studying polar bear populations in Canada as well. However, it's clear you are biased in your interpretation that overhunting is the primary reason for population decline - for example, the article you linked to does not say that, even though the quota was 105, 200 bears had been killed. You seemed to have pulled that number out of nowhere. Ask those indigenous communities if the warming should be cause to worry, and you'll get a clear positive answer. One of the very reasons they want to shoot polar bears is that the latter are going further inland every year, increasing the number of human-bear interactions (which almost inevitably end up with the bear being shot).
  14. European reanalysis of temperature confirms record warmth in 2010
    Yvan @15, Look at the second graph-- that is for the globe (a true global temperature, unlike the SAT data and even the MSU data). A clear warming pattern is evident. This is an estimate from looking at the graph, but for the period 1970-2010 the mean rate of warming I get is about 0.17 C/decade. Pity that ECMWF don't provide the mean rate of warming and/or actual numbers (then again, I have not undertaken a thorough search). TOP @14, ECMWF also have plot of Td (dew-point temperatures) available on their web-site, requires a little digging though.
  15. The contradictory nature of global warming skepticism
    Baz : "Because when warming didn't continue at the same pace (around 2005) I began to question if I was right about my beliefe in warming." What pace ? Since when ? What belief ? Didn't you accept the facts, then ? You just believed ? What figures do you remember from that time, which made you doubt ? Baz : "As I have said on here, I don't deny the facts - the physics of GHGs, but what I do deny is that we 'know' what the overall result will be (pos/neg feedbacks)." We don't 'know' anything about the future, in fact, but scientists can make projections and suppositions based on scientific work. What, among all that scientific output, leads you to believe that the "overall result" will be better than the consensus states ? Baz : "AGAIN(!) I'm not sceptical of warming thus far. I'm sceptical that warming will continue - that there will be a postive feedback from contuing with our release of CO2 etc." For what reason are you sceptical ? Why do you think that warming has stopped or will stop, or that the feedbacks will be of little consequence in total ? Baz : "The HadCRUt global series shows remarkable stability over the past 10 years despite an ever-increasing CO2 release. So five years ago I questioned if my belief was correct." I can't see that stability, myself : what with all the peaks and troughs showing between the beginning of 2000 and the most recent figure (shown here). It also shows a positive trend, although small (data here). I find it even stranger that you had such doubts, when you compare the 10 year trend up to 2005 - when you say you had your doubts. Still lots of peaks and troughs but the trend is much more positive. So, what exactly made you doubt the evidence ? As for your question, I would give it between 20 and 30 years before being able to even determine any sort of significant flat or downward trend because we have had those in the past, as has already been noted, and we would have to understand why it was happening before throwing away any theories. It would also be nice to have a replacement theory...
  16. The contradictory nature of global warming skepticism
    @Baz Five years is not a sufficiently long period to claim warming has stopped, especially since it's clear 2010 will be one of the warmest years on record. Fifteen years is barely enough to produce a statistically-significant thread with the amount of noise produced by natural cycles, but is *is* enough. As VeryTallGuy said, a 20-year period is a good start, assuming we cannot ascribe it to some specific phenomenon. It still doesn't change the fact that you didn't act in a rational manner by "losing your faith" over a five-year period.
  17. The contradictory nature of global warming skepticism
    @Eric: "in laymen forums I always ask the same question: what is the catastrophe?" So, for you the catastrophe has to take place first before we try to mitigate it? I'm sorry, but that is not a rational position. We are already seeing the dire effects of AGW in the oceans, we are already suffering the effects of increased extreme weather. You're basically taking a gamble with the future. "So far I can safely say there is no catastrophe" Tell that to Pakistanis and people in Moscow. As for polar bears, here in Canada they are being forced southward, so much so that they have (in at least one case) started mating with brown bears. Declining numbers here are *not* due to hunting, because polar bear hunt is severely restricted. It seems to me you like to cherry-pick evidence that supports your agenda. That's hardly what a real scientist is supposed to do, but it's entirely consistent with the kind of disinformation spread by contrarians. Your excessive caution in dealing with this threat might be justified if we didn't need to transition away from fossil fuels for *other* reasons, but the fact is that we do. It makes no sense to argue against such a transition, even if you're skeptical of the science. What other reasons would one have to argue in favor of keeping fossil fuels, a finite resource that is the cause for conflict and inequality?
  18. Why positive feedback doesn't necessarily lead to runaway warming
    A runaway greenhouse is one where the final temperature causes the ocean to boil away. At that point there is no way for a return to a lower temperature. Venus has a runaway greenhouse, so we know it is possible. Even there the temperature stabalizes at a high temperature. Dr. Hanson studied Venus and he feels that it could be a problem on earth if enough CO2 is emitted. The consensus is that it is unlikely to happen. Even without a runaway greenhouse it can get too hot for most of us.
  19. The contradictory nature of global warming skepticism
    Mosh @67: Pieces are slected [sic] because they are new, unusual, puzzling, contradictory. What you want is for somebody else, some authority, to settle the controversy. Anthony is happy to let his readers try. blood sport This is pretty much the issue I have with most of the soi-disant "citizen scientist movement." What is taking place at WUWT, at its best, is argument. Sophistry, if you will. That's all well and good, but it's not science. Pretty much every post and every comment there is suffused with the attitude "these scientists have no idea what they're talking about, I can understand this stuff much better than they." And perhaps some - even many - of those commenters could make a contribution, if they set aside 38 Ways to Win an Argument, got a science education, found a lab, and published. Instead it's just LOLs and WTFs. Nobody wants "some authority to settle the controversy." The controversy should be settled by good science, competently and transparently done. Not 'blood sport.'
  20. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    @ Dr. Pielke: In your most recent post (#194), you conclude by directing everyone to a website to learn more about global warming. The website that you direct us to seems to be the official website of the “Pielke Research Group.” Unlike most websites of this nature, your website does not contain a “Who we are” webpage. What is the Pielke Research Group?
  21. Why positive feedback doesn't necessarily lead to runaway warming
    The Ville #9 You beat me to it. I was going to comment the exact same thing, however, one could also question what is meant by "runaway". Doesnt the transitional state imply some degree of runaway?
  22. Why positive feedback doesn't necessarily lead to runaway warming
    Maybe the title needs to be changed. Something like 'Why positive feedback doesn't necessarily lead to runaway warming' And in the article, have something like 'although positive feedback can result in runaway..., it doesn't necessarily result in runaway..., here's why...'
    Response: I'm having a deja vu from this morning. Tonight when I tweeted this blog post, I inserted a (necessarily) into the tweet. Again, thought briefly about updating the blog heading, decided against it (mainly due to laziness). I hope all the authors (who are doing a fantastic job writing all these rebuttals) aren't getting too fed up with me creating all the distractions from their articles :-(
  23. beam me up scotty at 00:10 AM on 14 September 2010
    Why positive feedback doesn't necessarily lead to runaway warming
    Needed to read more carefully. Sorry
  24. Why positive feedback doesn't necessarily lead to runaway warming
    What about the release of methane?
  25. Why positive feedback doesn't necessarily lead to runaway warming
    Let me speak for Neal and explain that this article is meant to address the sentiment often expressed in comments here on Skeptical Science: if our climate has net positive feedback, why haven't we experienced runaway warming? So this rebuttal establishes one very simple point - you can have net positive feedback without experiencing runaway warming. So the rebuttal is not saying runaway warming is impossible. Given a strong enough positive feedback or a strong enough warming, it may be possible. But that's not the point of this rebuttal.
  26. Why positive feedback doesn't necessarily lead to runaway warming
    If the limit is above 100C, we will end up like Venus, because we will cook the oceans.
  27. Positive feedback means runaway warming
    I believe Hansen has said that it might be possible for Earth to get to runaway greenhouse warming if we burned all fossil fuels on the planet. Nothing in the article above speaks to such a scenario.
  28. Why positive feedback doesn't necessarily lead to runaway warming
    beam me up scotty, he's not. Or at least, it depends on what you mean by alarmist. Hansen did not say that runaway warming is the most likely outcome. Here are his words (p. 24): "In my opinion, if we burn all the coal, there is a good chance that we will initiate the runaway greenhouse effect." His sentence begins with a caveat, a big if.
  29. Why positive feedback doesn't necessarily lead to runaway warming
    re bmus: Has Hansen said there is no limit? If he says the limit is greater than what others are saying, it wouldn't suggest he has deviated from what this article has pointed out, since he would be suggesting a limit. 'Alarmism' is meaningless in the context of this article.
  30. Why positive feedback doesn't necessarily lead to runaway warming
    This is off-topic but, as usual, I don't know where to post it. For my book-in-progress on sea level rise, I'm making New Orleans one of my "poster children of sea level rise" and have just written a few pages on it. If anyone is interested in reading this draft, please contact me off-list at huntjanin@aol.com.
  31. beam me up scotty at 23:46 PM on 13 September 2010
    Industrial CO2: Relentless warming taskmaster
    Arkadiusz Semczyszak Do you think we can supply the worlds population with the energy it needs using only renewables, and do it in time to prevent the worst case scenarios of climate change? http://growthisnotsustainable.blogspot.com/2010/09/energy-reducing-co2-emissions-will-be.html
  32. beam me up scotty at 23:42 PM on 13 September 2010
    Why positive feedback doesn't necessarily lead to runaway warming
    So Dr. Hansen is an alarmist?
  33. The contradictory nature of global warming skepticism
    Congrats Ann #109, in just one paragraph you correctly put this complex problem in the right context: "I would stop believing in AGW if for a significant period of time (in the range of 15-20 years) global temperatures would not rise, [...], and if no other explanation could be found for this phenomenon." It should be as easy as this.
  34. beam me up scotty at 23:37 PM on 13 September 2010
    Positive feedback means runaway warming
    So Dr. Hansen is wrong?
  35. Roger A Pielke Sr at 23:34 PM on 13 September 2010
    Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    VeryTallGuy Thank you for an excellent question. Regarding the uncertainty estimates of the upper ocean heat content on a monthly basis, Josh Willis presented this in the figure in Pielke Sr., R.A., 2008: A broader view of the role of humans in the climate system. Physics Today, 61, Vol. 11, 54-55. http://pielkeclimatesci.files.wordpress.com/2009/10/r-334.pdf There are several interesting issues with this plot. First, the uncertainty is reduced later in the time period. Second, a test of the null hypothesis (i.e. no trend) cannot be refuted using this data. While on this weblog, there has been an emphasis on claiming warming over this time period. In other venues, however, there have been claims of cooling as the actual linear fit is slightly negative. Neither of these conclusions, however, are justified using this analysis. As I have written, however, my main recommendation is the adoption of the upper pcean heat content changes as the primary metric to assess global warming and cooling. I have further comments on this in my posts A Short Explanantion Of Why The Monitoring Of Global Average Ocean Heat Content Is The Appropriate Metric to Assess Global Warming. http://pielkeclimatesci.wordpress.com/2010/09/12/a-short-explanantion-of-why-the-monitoring-of-global-average-ocean-heat-content-is-the-appropriate-metric-to-assess-global-warming-2/ Further Discussion Of Global Warming http://pielkeclimatesci.wordpress.com/2010/09/13/global-warming-101-part-ii/
  36. The contradictory nature of global warming skepticism
    caerbannog, If Watts and Co. were serious, they would have been crunching numbers from the get-go, adding data from each new surface temperature station as as soon as it was surveyed. There is simply no good reason to procrastinate on the data crunching until their "survey" is entirely complete. You prolly know this,but a few people were doing exactly this in 2007/8, I think, at climateaudit. John V was one, and IIRC Steve Mosher was another. Over a period of months they had four threads done with a few hundred posts in each. They had (13 or 17) good stations (can't remember which) at that early stage, and the fit was extremely close to the official record at that time. But then it just stopped, and I've been asking around to find out why - having learned from Watts that the public, real-time project would not be continued. The temperature gridding/averaging process is not all that difficult conceptually -- basically it's a tedious programming slog. It's a straightforward task that any reasonably talented science/compsci/engineering undergraduate student could tackle. I read somewhere that these guys could do it in a day. John V has a website called 'opentemp', where I think one could crunch the numbers - if Anthony would release them. But he felt stiffed by NOAA over Mene et al, and won't part with any more data until the paper is published. I allow myself this one obsession. so here's a few links to that project. These are the four threads: First | Second | Third | Fourth This is a post from there where John V crunched the numbers (graphs went missing after CA crashed a while back). Watts' in-line reply saying he'll do the number crunching when 75% of stations are in. That was november 2008, and Anthony said there were 'a few months to go'. Announcement at WUWT declaring 80% of stations rated - June 2009. A year after that I politely asked Anthony about an update. His reply came with a free insult. I could link to the series of posts late last year where John V asked Anthony about releasing the data, but I've exorcised my demons for this year.
  37. How we know the sun isn't causing global warming
    Ken, I do not have any number by myself but I do know that those calculations do not consider the net clouds effect. More specifically, clouds block outgoing IR radiation too and emit (and reflect) electromagnetic waves differently depending on the type of cloud and altitude. Any discussion on the energy balance has to consider all these terms. I find those trivial calculations almost completely meaningless.
  38. The contradictory nature of global warming skepticism
    Hi Baz, A question for you: In 2005 you concluded that global warming wasn’t happening because the warming didn’t continue at the same pace ? How many years did you take into consideration to conclude that global warming has stopped/never happened ? To answer your question: I would stop believing in AGW if for a significant period of time (in the range of 15-20 years) global temperatures would not rise, or even show a slight cooling, in short if there was a statistically significant dataset that rejects the AGW hypothesis – and if no other explanation could be found for this phenomenon. By the way, It’s not just the man-made warming theory that would be in trouble. Unless a cause could be found for this cooling (like for instance: a marked increase in volcanic activity),the whole climate model and surrounding science would prove to be invalid, and a new climate theory would have to be built from scratch. It is unlikely that this will happen. Climate models have been used to explain past climate changes, and have been successfully used to predict future climate changes. This gives climate scientists some confidence that they understand what is happening.
  39. The contradictory nature of global warming skepticism
    Well put, les@103. You address very clearly why Baz should not be "losing his faith" over a blip in the temperatures. The rise of temperatures in the 90's was quite spectacular - much faster than models predicted. That this was followed with a slow-down is not surprising. Has any work been done on quantifying the period of time that global atmospheric temperatures might deviate from the trend? For example, if you look at the Dow Jones over the 20th century, you will find a couple of 10 year periods where stock prices stalled. So what is it, 10, 20, 30 years?
  40. European reanalysis of temperature confirms record warmth in 2010
    Arkadiusz - The "Rate of change" graph is interesting, although I always find it confusing to look at a derivative (rate of change) chart right after an anomaly (total change) chart. I prefer total change as more useful for state (how far we've gone), but derivative rate charts as more useful for examining any underlying process changes.
  41. Climate change: Water vapor makes for a wet argument
    johnd - I perhaps have been reading to quickly with regards to that chart, myself. That said, it's an agricultural data product, and not specifically intended as a measure of back radiation; hence the lack of back radiation data on it is rather unsurprising. However: My basic confusion (still unresolved) on your question is as to what, exactly, you feel this particular data set shows as issues with back radiation amounts? Back radiation measured, repeatedly, with different instrument sets, since the 1950's? It's definitely there, and in the amounts predicted by theory.
  42. How we know the sun isn't causing global warming
    Riccardo #48,49 Do you have a different number of W/sq.m for incoming solar than 239-240? Pray tell us what it is?
  43. European reanalysis of temperature confirms record warmth in 2010
    I dont want to be pedantic but focussing on the extratropical northern hemisphere largely increase the global warming signal compare to a true world average temperature.
  44. The contradictory nature of global warming skepticism
    Hello JMurphy. Happy to answer your questions (even though you and others haven't answered mine): "How can "that blue line" (that has been trending upwards since 1850) have turned you into a so-called skeptic and ex-member of Greenpeace ?" Because when warming didn't continue at the same pace (around 2005) I began to question if I was right about my beliefe in warming. "How could you have been a "believer in warming" rather than an accepter of the facts ? Why do you deny the facts now ?" That's a problem if mis-reading you have there which seems to have affected a number of people here. Is it common? As I have said on here, I don't deny the facts - the physics of GHGs, but what I do deny is that we 'know' what the overall result will be (pos/neg feedbacks). "How can you be sceptical of warming temperatures when the graph you give a link to shows warming temperatures since 1850 ?" AGAIN(!) I'm not sceptical of warming thus far. I'm sceptical that warming will continue - that there will be a postive feedback from contuing with our release of CO2 etc. "What ("a few years back") was so damning in your eyes ? Can you give the details ? What was the trend, and over how long a period ?" As I said, I re-looked at the issue around 2005. Up until around then I was a believer. I'm not fully in the sceptic camp apparently, but have pitched a tent outside. The HadCRUt global series shows remarkable stability over the past 10 years despite an ever-increasing CO2 release. So five years ago I questioned if my belief was correct. My question (again) to you and others is when will you question your belief: 10 years? 20 years? Only 'VeryTallGuy' has answered!
  45. European reanalysis of temperature confirms record warmth in 2010
    Where are the plots for global heat content anomaly and global dew point anomaly?
  46. A history of satellite measurements of global warming
    wingding #7, I disagree that criticisms of Spencer and Christy as scientists are baseless. I had linked to articles quoting them making what I consider blatantly unscientific / biased / false statements as evidence of this, but it was apparently deleted. Which seems somewhat overzealous to me. It was certainly no less polite than, for instance, comparing people who denounce Spencer and Christy to the "behavior seen at WUWT".
  47. The contradictory nature of global warming skepticism
    VeryTallGuy, many thanks for that, it's much sppreciated. So for you, it would be 20 years, that's fair enough. kdkd. No, it's not any approach at misdirection at all, it was simply a question! VeryTallGuy answers it, why not give it a try yourself? I wasn't actually referring to any previous bumps, as that would be prior to Tamino's 1975 start. But I wasn't referring to bumps at all, but prolonged stability or decline.
  48. The contradictory nature of global warming skepticism
    Baz, in addition to all the other answers pointing out the statistical fallacy of your argument it also requires acceptance of something we already know to be false... "Just suppose, for a minute, that this blue line carries on reasonably straight, or even heads down" Why would I do that... when we've already got eight months worth of data for 2010 showing it to be thus far the hottest year ever recorded? Your 'just suppose' scenario has already been contradicted by the actual facts. That said, the question, 'how long would it have to be flat or negative to disprove man made global warming', is inherently flawed. If you look at it at all logically you should be able to see that the duration of fluctuations depends on what causes them. That chart shows temperatures dropping from ~1880 to 1910... so obviously 30 years of declining temperatures didn't 'disprove man made warming'. If we started releasing all the particulate pollution we could and blotted out the Sun for 50 years the cooling from that wouldn't 'disprove man made warming' either. BTW, you should also work on your phrasing. The idea of 'disproving AGW' is ridiculous. AGW is an observed fact. In some of your posts you have specified that you question the extent of positive feedbacks. That is not wholly unfounded, but describing it as 'disproving mad made warming' is just nonsense. Extensive research has narrowed current 'climate sensitivity' to a range between roughly doubling warming from a forcing (in this case human CO2 emissions) to multiplying it by as much as a factor of five (with higher values considered very unlikely, but not completely ruled out). To 'disprove' that with a lower climate sensitivity you'd have to show some climate process which all that prior research overlooked or miscalculated. In the mean time, ponder this... climate science says a doubling of CO2 from the historical ~280 ppm to 560 ppm would produce about 1 C of warming and that feedbacks would increase this to at least 2 C or more (best estimate is currently about 3 C). We are presently at about 390 ppm... a 40% increase. Yet we have already seen over 0.8 C of warming. We're at nearly 1 C warming with less than half the CO2 increase needed (by itself) to get us to that point. How does that NOT indicate that net feedbacks are positive and significant? Especially since it is right in line with the projections of 3 C for doubling of CO2?
  49. Arkadiusz Semczyszak at 21:38 PM on 13 September 2010
    The Little Ice Age: Skeptics skating on thin ice
    ”Volcanic activity was high during this period of history ...” However, it appears that the high volcanic activity may be warming rather than cool. Sulphur aerosols act (higher albedo), a relatively short time - causing the cooling. Volcanoes “stratospheric” would erupt every year - as was the case during the Triassic. Volcanoes as an ozone-destructive - act in a very long period of time. Example: LIA - Tambora eruption in 1815 - "year without summer" in Europe - but the years 1818-3? was warmer or much warmer than before the eruption of the volcano. Ozone - the thinner the layer - the higher the mortality of marine phytoplankton. Phytoplankton and Cloudiness in the Southern Ocean: “The effect of ocean biological productivity on marine clouds is explored over a large phytoplankton bloom in the Southern Ocean (SO) using remotely sensed data. Cloud droplet number concentration over the bloom was twice what it was away from the bloom, and cloud effective radius was reduced by 30%. The resulting change in the shortwave radiative flux at the top-of-the-atmosphere was -15W m-2 ... ” Positive feedback - the more ULV = the less phytoplankton = the lower the cloud cover = more ULV ...
  50. European reanalysis of temperature confirms record warmth in 2010
    Re: Johngee (9) Figure 1 is for land areas north of 20 degrees north for May-June only. Figure 2 is for combined global land + sea areas. Both use a baseline of 1989-2001 and use anomalies instead of temperatures to reduce weather-related noise in the data. Both are surface-layer (2-meter) data instead of something like satellite-obtained data, which can also measure various layers of the atmosphere (the Earth's atmosphere is layered like an onion; because of this, it heats and cools differentially. The addition of CO2 essentially causes a differential accumulation of heat in the lower layers by slowing the transfer of heat to upper layers. Hence stratospheric cooling and tropospheric heating). Figure 1 shows that, in the 40 years of data shown, land temps away from the tropics have warmed in the last 10 years relative to the other 30 years of data. Figure 2 shows that global (land + sea) temps have been rising fairly linearly across the entire range of the data (if you were to put a ruler on the graph and draw a straight line through the midpoint of each year of the data, you'd get a line rising from the left side of the figure to the right side. This line is said to have a positive slope, showing the upward overall "trend" of temperatures in the data). Both figures show an essentially noisy dataset (even using anomalies to reduce the noise), but one in which a clear signal can be seen. It's getting hotter. And there is no indication of slowing in the rise of temperatures. Hope that's more clear! If you have more questions, let me know. The Yooper

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