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Comments 1 to 50:

  1. There is no consensus

    Peter... The point isn't that it took so long. Once actual evidence was presented scientists changed their position based on the evidence. The previous position was one where there was little active research that made up the basis of the consensus position. 

    AGW is not a case where little research is being done and scientists are just accepting what has been assumed.

    This is an issue that has been actively researched for 100 years. There are thousands of papers coming out every year on various aspects of man-made climate change. It's a field of intensive research.

    In the past 100 years there have been various challenges to the core idea that increasing greenhouse gas concentrations will warm the planet. Each of those challenges have been shown to be wrong. And in the meatime, more and more research is being published confirming the consensus position.

    The comparison to H. pylori is just not a valid.

  2. 2014 will be the hottest year on record

    robert way @16.

    It's not really cherry-picking as it's not just the NOAA (NCDC) that is set for the hottest year on record. The Jan-Nov NASA GISS average is also above the hottest calendar year on record, as is the HadCRUT4 Jan-Oct average. Likely BEST will show similarly.

    The satellite records, UAH & RSS, wobble far more with ENSO so the 'warmest year' is more to do with the size of El Ninos than rising global temperature. And today we remain without an El Nino, which is added reason for considering the surface temperatures worthy of note.

  3. There is no consensus

    645. I think we are at cross purposes here. Neither of us doubt that there was a, let's call it strong, or established if you like, consensus prior to the discovery of the effect of H. pylori. Neither of us disagrees that new evidence did change the consensus although I would argue that the fact that it took as long as it did illustrates that medics were very keen to hold on to their previous consensus view.

    Where we would probably disagree is on whether there is sufficient scientific proof underlying the consensus on the degree of man-made global warming and the degree to which that consensus is reflected correctly in the statements made at the top of this thread.

    I think that looking at the science and its credibility is important and that the use of "consensus" is being corrupted to give a false impression of certainty

    644. No. I am arguing that there is ignorance and you seem to be in denial of it! It is freely admitted by paleo-climatologists that they know a lot about many of the factors involved but not enough to know the exact reasons behind paleo-climatic changes. 

    Taking your Tom Curtis conclusion from Marcot et al:

    "Global temperature, therefore, has risen from near the coldest to the warmest levels of the Holocene within the past century, reversing the long-term cooling trend that began ~5000 yr B.P.

    and your conclusion from it:

    "In other words, little temperature wiggles up-and-down notwithstanding, human emissions are the only cause of the current sustained warming trend."

    The conclusion you draw cannot logically be made from that Marcot statement. There maybe many reasons for the cooling and for the most recent warming of which human emissions are likely to be a contributory factor. 

    The enormous evidence base that you cite does not preclude other factors causing the most recent warming and whilst you are right that there is a lot of knowledge about paleo climate I have yet to see anything that comes close to proof that C02 changes are the main factor in those. As I said before icecaps existed at both poles when C02 concentrations were 100 times the current levels.  

    ...."Unless you care to suggest that, say, plate tectonics, quantum electrodynamics, gravity-as-distortion-of-spacetime, and evolution of biological organisms are also "guesswork"."....

    I don't care to say it because they are all demonstrably true and repeatedly proven by observation and / or experiment. The theories and mechanics behind them have been, and are, still subject to many different "consensuses". But none of those causal theories are held as unshakeable truth in the way, say for example, that the movement of crustal plates is, via something described as plate tectonics. This will not be falsified.

    The same cannot be said for the claim that man-made emmissions of C02 are causing 100% (ish) of temperature increases on earth.

  4. What happens if we overshoot the two degree target for limiting global warming?

    A question: The World Bank commissioned report from 2012 about the prospects of a 4C warmer world states:  "Even with the current mitigation commitments and pledges fully implemented, there is roughly a 20 percent likelihood of exceeding 4°C by 2100. If they are not met, a warming of 4°C could occur as early as the 2060s."  You cite "the most extreme scenario" as being a 4C rise by 2100 at the earliest. This is quite a discrepancy - almost a 'halving' of the time period (from 2012) for such a rise. What is the it possible that it is due to an inherently conservative nature of the IPCC projections? (that is, assuming the mitigation commitments are NOT met, something that the world has amply demonstrated to be a possible if not probable outcome).

  5. Human CO2 is a tiny % of CO2 emissions

    CBDunkerson @263.

    The 0.006 value being quoted is probably ppm CO2 by weight which is roughly 1.5x the 'by volume' value for dry air.

    The 2%-7% is probably that derived from the relative size of CO2 fluxes into the atmosphere, from man-made sources and from natural sources, a particularly stupid value to use as the natural fluxes are bi-directional while the man-made ones only go one way.

  6. There is no consensus

    Peter Lloyd...  "You don't show in what way my H. plyori story has "little basis in fact" or isn't relevant."

    You stated that there was an unshakable consensus. I quoted for you the words of one of the researchers who discovered the H. plyori saying it only took a few years for his work to become accepted. That means, in actuality, that previous consensus was very quickly overturned by presenting the research.

  7. There is no consensus

    Peter Lloyd:

    You are essentially admitting to arguing from ignorance. Please desist (arguing from ignorance, that is).

    Maybe you don't know much about paleoclimate, but that doesn't mean nobody knows. (See chapter 5 of the IPCC AR5 WG1, or any paleoclimate articles at this website.)

    Maybe you don't know much about the sum of radiative forcings, or findings from paleoclimate, that allow climatologists to calculate that human emissions of greenhouse gases are responsible for 100+% of recent warming, but that doesn't mean nobody does.

    Regarding paleoclimate findings supporting "global warming is happening and we are the cause", see Tom Curtis' comment here regarding Marcott et al 2013; in which Tom notes that Marcott et al found:

    Global temperature, therefore, has risen from near the coldest to the warmest levels of the Holocene within the past century, reversing the long-term cooling trend that began ~5000 yr B.P.

    In other words, little temperature wiggles up-and-down notwithstanding, human emissions are the only cause of the current sustained warming trend.

    Maybe you don't know about the enormous evidence base that undergirds the consensus position, but that doesn't mean nobody does - in fact, the consensus position exists as a result of the evidence base (Like in any other field of science with a strong consensus position (*)).

    As just a tiny example, consider this Skeptical Science post discussing the basics of the greenhouse effect. Note the final image presented in the article, taken from Conrath et al 1970 in which they ran an experiment, comparing theoretically calculated vs. empirically measured infrared radiance.

    Kindly also provide actual documentation that the mainstream position among doctors and medical researchers regarding stomach ulcers was an "unshakeable consensus" as you assert.

    (*) Unless you care to suggest that, say, plate tectonics, quantum electrodynamics, gravity-as-distortion-of-spacetime, and evolution of biological organisms are also "guesswork".

  8. One Planet Only Forever at 01:27 AM on 19 December 2014
    2014 will be the hottest year on record

    Tom Curtis, Regarding the table of data @ 6,

    Though the variation of temperature values of the highlighted years indicate 2014 does not appear to be 'statistically significantly warmer', when you review the NOAA ONI values (here) for the period preceding the years highlighted it is clear that there is a statistically significant factor. 

    The El Nino bump of global average surface temperature clearly occurs shortly after the ONI indicates a warm event on the Tropical Pacific Ocean surface. Reviewing the magnitude of warm values in the ONI for the years of the highlighted 'warm' global average surface temperature it is possible to see the significance of 2014 being in the top group (and being number 1).

    1998 was the result of the most significant ONI set of July to June values for that set of years. It was clearly a massive ONI warm anomaly, resulting in a massive surface temperature anomaly. The other highlighted years also have more significant warm ONI values related to them than 2014, with the possible exception of 2013 which also stands out as a very warm year without a significant El Nino bump.

    Of course the ONI by itself is not what results in a temporarily warmer global average surface temperature. The integration and interaction of the ONI with the SOI combine to create the ENSO. Reviewing the SOI (here) the relationship between the SOI the ONI and global average is also clear. And there is also the dimming effect of volcanic aerosols which were also very low in 1998 compared to more recent years.

    So, more things considered, the 2014 global average surface temperature being the warmest so far does appear to be quite significant, perhaps even 'statistically very significant'.

  9. There is no consensus

    Thank you gents

    I haven't had a chance to read the paper and accept the point about endorsement of the IPCC position

    Thank you for agreeing that there are other factors at work in global warming and bearing in mind the strength of those as demonstrated by climate history then any claim that man - made factors are anywhere near as large as 100% or greater are going to have to demonstrate the current and past natural changes and how they interact. No one knows this yet.

    I would point out that the huge red circle at the top of this thread with the 97% figure in it says "Global warming is happening and we are the cause" without the caveat that it is not the only cause.

    As a result, however interesting it may be that half the population doesn't share the 97% figure, the concensus view remains guesswork and miles away from the experimentally demonstrated effect of H. pylori that I used as a contrast.

    You don't show in what way my H. plyori story has "little basis in fact" or isn't relevant. It is true that H.pylori is the primary cause of many stomach ulcers. There undoubtedly will be many elements of how and why that remain unknown as yet. The point is not to make too much of the fact that there was a strong concensus about the previous view. In general medical science is quite good about not creating an idea of certainty unless the experimental evidence is very strong indeed.

    My problem with the waving around of the 97% figure is it gives a false impression of the certainty if you don't temper it in the same pronouncement. 

  10. Human CO2 is a tiny % of CO2 emissions

    Brain Washed wrote: "I'm open minded about science, and willing to listen to anyone who can provide substantive information."

    You might have tried reading/searching first. The various arguments you present are all covered in the 'climate myths' section of this web-site;

    "the best I can tell, about .006, just over 1/2 of 1% of the atmosphere is made of CO2"


    No. The current atmospheric CO2 level is about 400 parts per million... 400 / 1,000,000 = 0.0004.

    the manmade portion of that amount is only 2%-7% (BTW, [400 - 280] / 400 = 30%, whoever told you 2% to 7% is really bad at math)

    Color me stupid, but I just have a hard time believing that has any impact whatsoever. 

    CO2 levels FOLLOW rising temps

    "Currently the consensus is that 15% of global climate change is due to the sun."

    P.S. Seriously, don't do Tom's hypothetical arsenic experiment.

  11. 2014 will be the hottest year on record


    Several factors affect the error over short time periods (like the time since the last three record temperatures).  The short time is not affected much by urban heat island effects while the longer period is.  Recent time periods have more stations and better coverage .  Both these factors make the error smaller for the recent time period than for the entire record.

    We have the additional larger error that the temperature record we are discussing is incomplete.  After the final numbers are released it will be easier to compare several records (as Robert suggested) and the actual magnitude of the difference will be clear.

    Robert: can you give us a hint what the satelite kriged (sp?) data might look like for the year? 

  12. Human CO2 is a tiny % of CO2 emissions

    Common Sense > Brain Washed:

    1)  Benjamin Franklin said it best:

    "Common Sense is neither common nor sensical. Much of what passes for common sense is not based on any underlying principle it’s just anecdotes that have worked for the current situation."

    2)  Your "common sense" requires not only that much of the public be brainwashed but that the vast majority of climate scientists have undertaken a conspiracy to delude the public.  That is not common sense in any terms, but much closer to the ravings of a loon.

    3)  And for the moderator, if an offensive wanker (profanity removed) is allowed to use a monikor that amounts to an accusation of massive fraud by scientists, then he should be expected to take his lumps in turn.

    4)  I will be convinced that small concentrations are irrelevant when you sit in a chamber containing 400 ppm Arsenic pentaflouride (LC50 at 20 ppm) for an hour and tell me who little effect it has had. 

    (Warning:  Just in case your sense is as sensible as your post suggests, LC50 means a 50% probability of death as a result of exposure to that concentration for an hour in test animals.  Do not conduct this experiment.)

    Moderator Response:

    [JH] Your point #3 is spot on. I have also issued Standard Moderation Comment #1 on his/her post. 

    [PS] Please observe comments policy  on profanity

  13. 2014 will be the hottest year on record

    greenman has drawn attention to the Gaurdian version of this post, as well as providing more information from

    In the comments, omnologos (of illfame), attempts to suggest the "uncertainty was 10 times bigger" than the projected margin in a 2008 paper about the NCDC temperature index.   He appears, however, to be citing the mean uncertainty for individual station records (0.2 C standard error) rather than the mean uncertainty for the global mean temperature record (0.03 C standard error over the period 1951-2000, see Table 5).  I draw attention to this because that mean value represents a smaller error than that I cited above.  That may be partly due to the additional months data, but may also be partly due to there being more temperature stations in the period prior to 2000.

    I also draw attention to it because I am unable to comment on greenman's site due to third party registration reqirements (sorry, just not going to sign up to twitter to comment at another site).  Somebody not so restricted may wish to draw attention to omnologos's error.

  14. 2014 will be the hottest year on record

    Isn't this cherry picking in the same way we accuse contrarians of doing so - picking an individual temperature series which supports a particular narrative. There are multiple datasets out there which do not agree that 2014 will be the warmest on record - that should be considered here.

  15. 2014 will be the hottest year on record

    michael sweet, try here

  16. 2014 will be the hottest year on record

    GISS always discusses their error and if the difference between the current year and other years is significant.  Once we reach January this data will be readily available.  GISS often says years are tied because the difference is not significant. Hansen 2010 claims on page 16 that their standard deviation = 0.025 between close years.  They claim two years are different if they are 1 standard deviation or more separate.  This is very close to the .024 in the  OP.  We will have to see what the data ends up being. 

    Tom: your link to NOAA does not work in my computer.  

  17. 2014 will be the hottest year on record

    devobrun @11, I've looked another way in which "0.024 C" might be considered a big margin by comparing with the mean margin of new global temperature records.  As it turns out, that mean is 0.037 C, and the median is 0.029 C, so even on that basis it is not a large margin.  Indeed, it would represent the 15th smallest increase in the record out of 22 such increases.

    Interestingly, only one new record in the full 135 year record represented a statistically significant increase over the prior record - 1998.  Indeed, on average, only the fourth new record after any given record differs from it statistically.  Based on that, we would not expect 2014 to be statistically distinguishable from 1998 (which it is not projected to be), but do expect it to be statistically distinguishable to the prior record year to 1998 (ie, 1997).  As 1997 had an anomaly of 0.514 C, that is almost guarantteeed.

  18. Two degrees: Will we avoid dangerous climate change?

    Gosh, and all of this for only a 66% chance of limiting warming to 2 degrees? It doesn't seem likely, does it.

    And AR5, I seem to remember, gave those budgets in ranges, all of which start at zero. That is, it's possible that we've already used up the budget to keep warming to below 2 degrees.

    Simon is right, though, 3 degrees is relatively better than 4 degrees and 4 degrees is relatively better than 5 degrees. At what point does it make no difference to our fates? Is 9 degrees better than 10 degrees, for humans (and most other species)?

  19. Is Earth’s temperature about to soar?

    I agree with this post

    even if not completely.

    Regarding long-term (I mean > 30 years) trend, the global surface T data from approx 1970 shows a clear and stable rise, with good approximation linear.

    Of course it is difficult to see it on the rough data with the average global T for months or years, but if we look at the trend with even if with a short smoothing (i.e. 6 months)

    (using Cowtan“calculator” is easy)

    the uphill is still recognizable while the fluctuations (which are real, non merley noise) are disturbing our eye.

    It is better for this reason use longer moving average (I suggest at least > 96 months): if you try (again starting from 1970), the whole trend will be very close to the linear regression, as showed by Tamino in his smoothed trend. But if you look at some smaller details (on the line with a long moving average but not on Tamino trend) you can see a little increasing of the slope just before 2000 and a small deceleration on the late ’00.

    We can call this behaviour a short-term (I mean approx. 10 years) slow-down? I think yes,

    as a matter of fact decreasing th moving average to 48 months (because we are looking for short-term trend) and starting from 1985 (in this way we are using the calculator as a magnifier) we found the same behaviour:

    faster warming after 1995 ( we know that 1998 was a record year) and deceleration after 2005 but also a steady increasing from approx. 1997 to 2005 as well as a detectable cooling from 1990 to approx 1995.

    Of course the moving average itself introduce some disturbance because we are at the border of the series and we don’t know the data regarding T for the next months and years.

    But don’ t worry, the recent short-term slow-down is not significative on the long-term and it is easy t o foreseen for the next 25-30 years (and after) a general increasing (smoothing the fluctuations that in every case will happen) of the T with an average slope of approx. 15 hundredths of degree per decade or more.

    Unfortunately the warmer is not always the better.

    P.S: if you want to find a long term slow-down or pause (of course with short-term slope changing due to fluctuations, a sort of warming and cooling small waves) you can lok at the data from 1940 to 1970 with a moving average of approx. 48 months (not surprisingly you can see the same general trend on Tamino model fit for this span but the fluctuations are flattened).

  20. Common Sense > Brain Washed at 19:05 PM on 18 December 2014
    Human CO2 is a tiny % of CO2 emissions

    This landed in my mailbox a day or so ago. It comes from a gentleman whose speciality is Heliophysics. In addition to what he has to say here, I'd like to add that, the best I can tell, about .006, just over 1/2 of 1% of the atmosphere is made of CO2. And of that, depending on who you believe, the manmade portion of that amount is only 2%-7%. Either way, we're talking about an infinitesimal figure. Using the 7%, that still only comes to .000042 of the atmosphere is affected by manmade CO2 emmissions.

    Color me stupid, but I just have a hard time believing that has any impact whatsoever.

    Now, I do not claim in any way whatsoever to be a scientist. Those numbers are what I grabbed from a few of what I consider to be reliable internet sources.  Please, if you have evidence to prove me wrong, by all means, do so. I'm open minded about science, and willing to listen to anyone who can provide substantive information. I think the main thing, which I've found from many sources, as the guy I'm quoting below points out, is that CO2 levels FOLLOW rising temps, not vice versa. Like I say, I just study as much as I can on something which interests me and try to make a sound conclusion based on what I find. And I am in no way offended by conflicting information. We'll just have to look deeper into the backgrounds of the sources to see if they have anything to gain or lose one way or the other.

    "Currently the consensus is that 15% of global climate change is due to the sun. I think that this might be a bit low. for the last 10 years GISS [I assume he's referring to the Goddard Institute for Space Studies at Columbia University] has seen a decreasing, trend of global temperature. I would caution that the decrease is consistent with no change. CO2 continues to increase. Further the glacial record shows that increases in CO2 levels lag global temperature increase."

    Moderator Response:

    [JH] On this site, it's considered to be in poor taste to include more than one denier myth in a single comment. It's also in poor taste to try to disguise where you are coming from by quoting someone else.

    Please note that posting comments here at SkS is a privilege, not a right.  This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.


  21. 2014 will be the hottest year on record

    devobrun...  Dr. Abraham is at the AGU conference in SF now, right after returning from Africa where he's been doing humanitarian work. You might be waiting a while for a response.

  22. 2014 will be the hottest year on record

    Thank you Tom, but I would like John to address the statement that 0.024 degrees is a "big margin in terms of global temperatures".

    Assuming that your data is correct, Tom......what is John's reasoning for his statement? 

  23. One Planet Only Forever at 14:31 PM on 18 December 2014
    2014 will be the hottest year on record


    I refreshed my NOAA ONI webpage and see that it already shows the most recent 3-month average SON 2014 to be 0.5 C. So the El Nino ONI condition has initially reappeared for the first time since the two consecutive values in 2012 (0.5C in ASO and 0.6C in SON).

  24. One Planet Only Forever at 14:18 PM on 18 December 2014
    2014 will be the hottest year on record


    Some minor clarification of the references to the potential El Nino may be in order.

    The NOAA ONI records that are used to evaluate El Nino/La Nina (see here), do indeed Red Highlight sets of 5 or more consecutive 3 month averages being 0.5 C above the baseline 30 year average. They are noteable warm events. Until the 5 consecutive values have occured there is no highlighting. So what is imminent is the first value of 0.5 C or warmer. That is indeed the threshhold for an El Nino, but to be on the record as an El Nino there will need to be 4 more consecutive 0.5 C or warmer values.

    The earlier reference in the article to El NIno is consistent with the above, but the later comment

    "Interestingly, we are currently close to an El Niño, and if current patterns continue for a few weeks, an official El Niño will be announced."

    should be clarified to be the start of the potential 5 consecutive values that would constitute a significant warm ONI event or noteable El Nino event.

  25. 2014 will be the hottest year on record

    RH, thanks!

  26. 2014 will be the hottest year on record

    I apologize for the blank space above the table in my prior post.  I have no idea why it is there, or how to fix it as it does not show in the html code.

    Moderator Response:

    [RH] All fixed! :-)

  27. 2014 will be the hottest year on record

    devobrun @5, NOAA lists the error margin for their global temperature series as being 0.1 C, so I do not think Abraham's claim is justified.

    Interestingly, poking around with the data I find that 9 other years are statistical ties with Abraham's projected temperature.  They are blolded in the list below.  You will also notice from taht list that 16 of the last 17 years (including 2014) are ranked in the top 17 hottest years out of 135, and all are in the top 20.

    NOAA temperatures since 1998.  2014 temperature projected.  Bolded values are a "statistical tie with the projected value for 2014.  Rankings are for the full 135 year record.


    Moderator Response:

    [RH] Converted html to image.

  28. 2014 will be the hottest year on record

    "I predict the annual temperature anomaly will be 0.674°C. This beats the prior record by 0.024°C. That is a big margin in terms of global temperatures."

    Have you got the standard deviation associated with each mean?  That might back up your last statement.

  29. 2014 will be the hottest year on record

    Michael sweet, that's easy.  The first year that the temperature is less than the latest record will be the start of a 'return to normal' or 'end of warming' or whatever their current catch-phrase will be.

    Just look at the artic.  After a record-breaking 2007 in 2008 they started talking about the 'recovery' ditto 2013 after the record 2012 mel5.  There's nothing too ridiculous for them to use to downplay global warming.

  30. 2014 will be the hottest year on record


    Excellent post.  Would it be possible for you to update your daily average once or twice more before the official records are released for the year (perhaps on this thread)?

    As I understand it, the strongest effect of El Nino on global temperatures is about 6 months after the El Nino starts.  That will be a couple of months from now.  If that holds for this El Nino, next year will also be a new, hotter, record.  How long will we have to go to get a negative slope for the escalator graph after two record years in a row?

  31. 2014 will be the hottest year on record

    I would like to point out that even if 2014 had been an El Niño year, we have had El Niño conditions before and they have not always resulted in record breaking warmth.  For the denier crowd to focus on only that as cause for record warmth is a non sequitur.

    I got a chuckle out of the "climate science deniers have had a bad year" comment.  Just over a year ago I had a half page letter to the editor response published in The Columbus Dispatch which completely discredited a Cal Thomas column where he claimed that 2013 was a bad year for the global warming crowd and hoped that it would be the last we heard of the whole idea.  Funny how reality can come back and bite you.

  32. 2014 will be the hottest year on record

    “These climate science deniers have had a bad year.”

    Not really. They would have if their arguments were based on reality, but they aren't. They're based on ideological expediency.

  33. PhilippeChantreau at 02:21 AM on 18 December 2014
    Hansen's 1988 prediction was wrong

    The moderation policy at SkS and the overall tone is far better than most other internet forums on the subject. I have read through this thread and I could not find an ad hominem argument against you TallDave. Can you quote or link the specific post that contained that particular logical fallacy?

    Moderator Response:

    [JH] Phillipe, TallDave's most recent post constituted argumentative sloganeering and was therefore deleted. He/she seems bent on relinquishing his/her privelege of posting on SkS.

  34. Hansen's 1988 prediction was wrong

    CBDunkerson: You may find the answer to your question in:

    The 7 psychological reasons that are stopping us from acting on climate change by Chris Mooney, The Wonkblog, The Washington Post, Dec 11, 2014

  35. Hansen's 1988 prediction was wrong

    This is a bit off topic, but TallDave's assault on 'cutting edge 1980s science' helps illuminate a pattern I've seen before. Essentially, there seems to be a mindset amongst many deniers which reasons that belief in scientific principles derives from faith in individuals... so the goal becomes an effort to discredit individuals they see as the 'preachers' (?) of science rather than the actual facts.

    For example, even if Hansen got some things wrong in the 80s (and he did, ironically just not the things TallDave is harping on) that would do nothing to invalidate modern global warming science. Over the past 30 years we've accumulated vastly more confirmation than Hansen had in the 80s... yet the mindset remains that if you can bring down someone viewed as the 'original actor' then all the facts just go away.

    We saw the same thing with Beck's assault on Callendar's atmospheric CO2 level analysis... decades after Callendar had died and Keeling had proven him correct. Ditto the endless assaults on Michael Mann despite dozens of subsequent studies having confirmed the findings of the 'hockey stick'. Similarly, whenever I've discussed evolution with creationists they have been endlessly fixated on supposed errors by/flaws of Darwin... as if there hadn't been two hundred years of additional confirmation since then.

    I don't know what this pattern of fixation on individuals / 'originators' means, but it shows up reliably enough that I suspect there must be some underlying reason. Does any of the 'psychology of denial' type research shed any light?

  36. Hansen's 1988 prediction was wrong

    Talldave would have us accept Lindzen's model that the temperature would stay the same, rather than Hansen's model that temperature would rise.  He ignores that record high temperatures have been set every five years since 1988, including 2014.  2014 will be the highest ever recorded and the hottest the Earth has been in thousands of years. 

    Talldave wants to wish away the temperature data and claim that the temperature is not rising.  If Hansen cannot predict in advance when people would reduce pollution than the temperatures canot be rising.

  37. Even climate change experts and activists might be in denial

    Mostly on target. But attachment to this position can become a black & white approach. After all, can't I save the world with some green app for cool shopping?! Rilly now, we gotta differentiate who should go to a climate conference and who's a waster. And, defensively I say, sail transport — even with auxiliary engines possible for a while longer — may be technically a "splitting" but is also essential for preparing for the fuckin' -(snip)- future. See

    Moderator Response:

    [RH] Watch the tone, please.

  38. Hansen's 1988 prediction was wrong

    "Concentrations are not emissions. If Hansen's explicitly described emissions scenarios didn't result in the concentrations he expected them to, that's a failure of his model. Pretending otherwise is the just the kind of three card monte that is causing the public to justifiably lose faith in climate science as an objective enterprise." (my emphasis)

    And "scenarios" are not "models," as has been described ad nauseum. This is the kind of double speak that makes people use the word phrase "climate denier" instead of "climate skeptic."

    People run scenarios all the time, with finances, with their shopping, with personal life choices. They choose among scenarios using "models" that can allow them to determine which scenario produces the most favorable or viable outcome.

    If I choose to save more money and my bank account increases as a result, it does not invalidate the same accounting model that has me go broke if I spent way above my income. The scenario (what I chose to do with my money) is different from the accounting model that turns that choice into a result. The same is true of Hansens study — he tried to capture a range of possible scenarios so people could understand the consequences of different actions.

  39. Hansen's 1988 prediction was wrong


    It is incumbent upon you to translate the EPA emissions data (shown as Tg of CO2 emitted over time) into radiative forcing over time. Otherwise, you have no ground on which to claim that the EPA data supports you.

    When even the work of a self-styled "climate skeptic" refutes your claim, IMO you should probably look at your own position for error instead of repeating it ad nauseum without any modification - a behaviour which, by the way, is prohibited by the Skeptical Science comments policy.

    I might add that characterising the work of tens of thousands of researchers across the world as a common con game is, at best, dancing on the line of an enormous accusation of deception.

    The fact of the matter is that climate science is based first and foremost on rather basic thermodynamics (net radiative energy in vs. net radiative energy out), the radiative properties of the greenhouse gases, and the thermal properties of the atmosphere and ocean. Speaking bluntly, you're setting yourself up for a hopeless task if you think that your attempt at refuting Hansen's 1988 work will unravel the physics establishing the reality of global warming.

    Also speaking bluntly, arguing against climate science in 2014 by reference to Hansen's work in the 1980s is equivalent to, say, arguing against oncology in 2014 by reference to where the knowledge base of that discipline stood in the 1980s. Such a line of argument says little to nothing about the science but much about the person who resorts to it.

  40. Hansen's 1988 prediction was wrong

    The EPA is not lying.

    Concentrations are not emissions.  If Hansen's explicitly described emissions scenarios didn't result in the concentrations he expected them to, that's a failure of his model.  Pretending otherwise is the just the kind of three card monte that is causing the public to justifiably lose faith in climate science as an objective enterprise.

    "Contrary to TallDave's missinformed epistemology, there is no logical difference between forecasting and hindcasting."

    I'm just going leave that there to speak for itself.

    Moderator Response:

    [Rob P] - Sloganeering struck through.

  41. Tree-rings diverge from temperature after 1960

    That was thoughtful of you to protect your blog from my post.  Surely most of the reader already know that CO2 has a shielding limit once the critical concentration is reached that completely blocks the IR the narrow band areas not overlapped by water vapor.  But this post only makes sense if you allow my prior post back. 

    Moderator Response:

    [PS] Offtopic. If you want to comment here, you must abide the comments policy. If you do not, then posting rights will be forfeited. The right place to comment (after you have read the science and can back your comment) is "CO2 effect is saturated". Use the search function on top left to find appropriate place. Repetition of long-debunked myths without new data is simply sloganneering.

  42. Antarctica is gaining ice

    Just thought that I would note that there is very nice review article on Antarctic sea ice increase and theories about why this happening by Eric Steig here. In short, it is the winds, but it is also rather complicated. Also, the transient response (what we see here) is likely different from the equilibrium response. It also points an interesting paper by here where a model driven by all the observed changes in winds pretty much reproduces the pattern in sea ice seen. h/t to Realclimate but thought this was an interesting addition to this thread.

  43. Tree-rings diverge from temperature after 1960

    To summarize, supporters of Michael Mann are annoyed at the dust up about him splicing direct NOAA data on the end of 960 years of proxy data when we know now that many climate scientists knew about this, called it "the divergence problem," and were OK with Mann not clearly labeling what he was doing for the world policy makers.  The big story about 2009 is need for better email security and need to catch science hackers.  Because the "data trick" to "hide the decline" got miscontrued by many due to bad non-scientists like Sarah Palin.  All real scientists know that the Briffa data set was perfectly valid until 1960 when modern interferences caused it to be invalid from there on.  And, we all know that warming must be occuring becuase atmosheric CO2 in known to cause rapid warming (not gradual or minimal) because we see in the ice core record that warming is always associated with higher CO2, even though the "lag problem."  The CO2 increased always after the warming but this is an even more alarming observation because it means that warming can be triggered by a small amount of CO2 that then causes a run-away spiral of more and more CO2.  And we don't know how the warming stopped, the CO2 declined and the oceans and land recovered.  Conclusion: we need to take action to freeze industrialization or better, reverse it along with population but currently lack necessary political structure to do so.

    Moderator Response:

    [PS] Welcome to Skeptical Science. Please take time to review the comments policy. Comments that do not conform will be deleted. In particular, please note the "No sloganeering" and "No Accusations" section. You are very welcome to discuss the science and article content, supporting your arguments with appropriate data and references. However, it would pay to first read the articles.

  44. 2014 SkS News Bulletin #6: LIMA COP20 / CMP10

    To me, that is essentially the same as 3 but you providing detail of mechanism for carbon trading and for development. The essentials are the same: the rich emissions go down a little, the poor rise a little; poor get money for development. I think the objections are largely the same: how to ensure money flow from rich to poor (which restores some historical equity) goes to where you want it without interfering in governance of receiving state.

  45. 2014 SkS News Bulletin #6: LIMA COP20 / CMP10

    scaddenp @3, you forgot:

    4/  Everybody agrees now to an equal per capita limit and staged reduction of that limit, with the limit set based on populations at a fixed date so that countries that allow their population to increase cannot evade capping CO2. 

    This is a guaranteed equitable approach, although not perfectly equitable as it allows western nations a greater cumulative emissions.  This approach comes in two versions:

    4a/ The initial cap is set at a level achievable by the most polluting nations, and emissions trading is not permitted; and

    4b/  The initial cap is set at current global average per capita emissions, and trading of emissions permits between nations is permitted on the provisio that capital recieved in the trading is used to:

    i) invest in renewable energy and associated energy infrastructure;

    ii) climate adaption programs; or in countries with most need

    iii) programs addressing current structural causes of poverty or ill health.

    4b permits an immediate cessation of increases in net global emissions, while providing a larger incentive for rapid reduction of emissions in Western nations. 

  46. 2014 SkS News Bulletin #6: LIMA COP20 / CMP10

    In my highly personal and not necessarily brilliantly informed opinion, there are basically 3 ways to make a deal:

    1/ Everyone caps their emissions now. This a no-equity solution where the rich countries stay rich (they got wealthy burning the fossil fuels and responsible for 70-80% of the extra CO2 in the atmosphere) and poor stay poor, but hey, if you dont stop emitting, then poor countries would cop the worst of effects.

    2/ The rich countries cut emissions to near zero  quite quickly and let poor increase emissions. This is equitable and doesnt involve wealth redistribution (at tax level) but good luck selling that to powerful rich countries where the required rate of emission drop would cause economic pain.

    3/ Rich countries take more modest drops (but still quite quick) and poor  make very modest increases, but get assistance in developing clean energy and development. Sounds reasonably equitable but runs into screams from rich countries about "my tax dollars getting siphoned by some rich dictator" and poor countries complaining of rich countries trying to run their affairs.

    All three options sound extremely difficult to sell to me. For rich countries the option of Screw-the-planet-because-I-wont-be-bearing-much-of-the-cost is all too appealing especially to their voters and most are democracies.

  47. Two degrees: The history of climate change’s ‘speed limit’

    Joel_Huberman @5.

    Figure 3.3 in Australian Government - Climate Change Authority (2012) "Targets and Progress Review Part A Chapter 3 A global emissions budget for 2 degrees or less."

  48. 2014 SkS News Bulletin #6: LIMA COP20 / CMP10

    Is there any chance that the good folks who run this sight, whom we have come to trust and cherish, would consider weighing in with their own assessment of the outcome of the Lima talks?

    Moderator Response:

    [JH] Thanks for the positive feedback and suggestion. I'll pass it on to the all-volunteer SkS author team.

  49. How much will sea levels rise in the 21st Century?


    From Jevrejeva 2014:

    "There is a good agreement between the rate of sea level rise (3.2 ± 0.4 mm·yr− 1) calculated from satellite altimetry and the rate of 3.1 ± 0.6 mm·yr− 1 from tide gauge based reconstruction for the overlapping time period (1993–2009). The new reconstruction suggests a linear trend of 1.9 ± 0.3 mm·yr− 1 during the 20th century, with 1.8 ± 0.5 mm·yr− 1 since 1970."

    It appears the skeptics are quoting the sea level rise over the 20th century.  Since the sea level rise is accelerating, using this longer time period lowers the reported rate.  If you measure the most recent 30 years Jevrejeva agree with the oft reported 3.2 mm/yr from satellites. Skeptics appear to claim deceleration from the 1970 to present rate.

    That seems ok if you don't mind overlooking the fact that sea level rise is accelerating.  If we average over the past 1000 years the rate will be almost zero!  No problem!

  50. How much will sea levels rise in the 21st Century?

    I'm noticing some people are quoting Jevrejeva et al 2014 as proof that mean sea level rise is nowhere near the often quoted 3 mm/year, and in fact is more like 1.8 mm/yr and decelerating..  Curious what is the story of this recent study?

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