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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 61551 to 61600:

  1. Climate Sensitivity: The Skeptic Endgame
    Ah, TIS, I see that your "skepticism" is extremely selective. So because a few short years don't fit your "expectations" of what CO2 should have done-in spite of the fact that it can be easily explained by the fact that the bulk of the planet's 2.5 billion people didn't even *have* electricity at that time-or cars-& at least half of the remainder were off fighting a war in foreign countries. As has already been pointed out, the fact that most of Europe's economy was constrained by *rationing* is a *known* *historical* *fact*.

    As to your other claim, it's a load of rubbish. In spite of an overall decline in sunspot activity for the period of 1961-2000, temperatures rose at a rate of almost +0.12 degrees per decade. By contrast, when the rise in CO2 was a lot smaller, but sunspot numbers were rising extremely quickly (1901-1940), temperatures warmed at a rate of only +0.08 degrees per decade. How do explain that if sensitivity to CO2 is so low-or is this another claim made by "skeptics" that can't be backed up by hard facts?
  2. The Inconvenient Skeptic at 22:32 PM on 2 March 2011
    Climate Sensitivity: The Skeptic Endgame
    #15

    Marcus,
    Solar activity (I assume you mean sunspots) has never really been too convincing to me. I have run plenty of comparisons, but it always seems weak. Some of that poor correlation you refer to is high activity with low temperature. If the activity in the 1938 caused the warm 1940 period, then the peaks in the 50's and 60's should have caused more. The 1956-1960 sunspot activity might be the most active period in thousands of years, but the temps were not high. That is poor correlation.
  3. The Inconvenient Skeptic at 22:14 PM on 2 March 2011
    Climate Sensitivity: The Skeptic Endgame
    Shoy,

    A few data points on a video are not convincing that WWII had no impact on CO2 levels.

    Regardless, there is little temperature rise from the start of monthly CO2 data until the 1990's. CO2 did rise a great deal in that same period of time.
  4. Roy Spencer’s Great Blunder, Part 2
    As for the problem of the rising of the emission level above the tropopause (Peter Offenhartz #8), the height of the tropopause depends on temperature. An increased GHG absorption will move both the tropopause and the emission level upward.

    In equilibrium and at wavelengths where the atmosphere is optically thick, the emission level will roughly be that corresponding to the effective temperature of the planet of about 220 K. In reality, the absorption coefficient depends on the number concentration of CO2 (number of molecules per meter squared), not relative concentration (ppm), and hence on pressure and altitude. Detailed calculation are required.
  5. Climate Sensitivity: The Skeptic Endgame
    TIS-there are studies that shows an 80% correlation between solar activity & temperature variation for the period of 1900-1950. For the period of 1950-2000, that correlation fell to less than 40%. This drops to less than 20% for the period of 1980-2000. Put another way-sunspot numbers rose significantly during the first half of the 20th century, causing a relatively slow rise in global temperatures over this period. In the second half of the 20th century, sunspot numbers have remained either static-or have fallen-yet temperatures have risen *faster* than in the first half of the century.
  6. Climate Sensitivity: The Skeptic Endgame
    3. HuggyPopsBear
    "I recognize pollution is a problem of mankind and something needs to be done, but CO2 is not necessarily a pollutant as it has many benefits for sustaining life and plant growth."

    There is nothing which is necessarily a pollutant.
    Things are just pollutants when they are in the system in such quantities as to cause harm in some way.
    Noise and light are not necessarily pollutants but we're quite happy that they can be polluting. Equally many heavy mettles are more clearly pollutants but exist all over the show in small quantities.
    It's an oft used fallacy that because something is required for life it can't be a polluting; and even if, to some degree, more is better - it doesn't follow that to a higher degree, much much much more is better.
    Sure CO2 is required for life and, to some degree, more CO2 is good for plants directly. That makes no difference to it's impact on the climate and overall environment!
    Same's true for oxygen. We - and most animals - need it. To some degree we can perform a little better with a bit more. However we can't use more than our blood can carry on the one hand; and on the other hand oxygen is extremely dangerous and our bodies have to work very hard to avoid being harmed by it.
    You really have to understand the system under consideration to understand pollution!

    As for your previous comment "tax a probability" - really?
    Most countries have armies which are not fully destroyed, because there's a probability the'll be needed or a probability they will deter aggression.
    Many people have health insurance - and many countries have compulsory health insurance - at a level based on the probability of getting ill, with the impact of illness factored in.
    etc. etc.

    Finally, as for "governments greed" ... who knows - certainly not the arctic ice. It doesn't know whether your or my government is greedy or not, it just keeps on melting...
  7. Climate Sensitivity: The Skeptic Endgame
    TIS #12,

    Surely you exaggerate the "massive quantities" of CO2 released in 1937-1950. The world economy was far smaller than it is now - heavy industrial production was largely confined to a few countries in Europe, and to the US. The late 1930s saw a resurgence of depression in the US. That was reversed in the war, but the latter end of 1939-45 saw total devastation of German and Eastern European industry. Britain was still under rationing until the late 1940s. BTW, I though ice cores gave an accurate picture of CO2 levels prior to recorded observations from 1957 or so.

    Getting the data in this video should help

    Visualizing the History of CO2
  8. Crux of a Core, Part 1 - addressing J Storrs Hall
    Charlie A @37, I'm sorry, I missed that part of Hall's article where he said, "Although I am using a regional temperature only, I am comparing it to a global temperature. Global temperatures show much less variation than regional temperatures because different regions of the world will be warming while others cool. Therefore any comparison between global and regional variation is essentially meaningless. But here goes..."

    I also missed that part where he said, "Although nineteenth century temperatures are much cooler than 20th century temperatures, I am treating the final temperature in this series, from 1855, as though it was representative of late twentieth century temperatures for rhetorical reasons."

    I especially missed that part where he said, "It is known that temperatures in the last decade are at least 1.44 degrees higher than the last point on this graph at the location of the ice core. This makes the late twentieth warming one of the most abrupt on the record, with the distinction that it, unlike the others on this record, was global rather than regional in extent."

    In fact, the only bits I noticed was where he persistently compared local to global temperatures as though that was a reasonable thing to do.

    If he had wanted to do an honest analysis, his graph would have looked like this:


    (With thanks to Gareth Renowden.)

    The reason he didn't actually draw modern local temperatures on the graph is because it would have made it perfectly clear how utterly laughable is his entire argument.
  9. Crux of a Core, Part 1 - addressing J Storrs Hall
    Dr Hall shows us temperatures up to 100 years ago and demonstrates that local temperatures had been at least 3C warmer than it was 100 years ago therefor global warming is 'poppycock'.

    This is why they are skeptics. "If it can be shown to have been warmer at some point during the holocene than it was 100 years ago, atmospheric physics is a con job."

    Lets not forget Wattsup is the website that described all those paleoclimatologists who they describe as 'The Team' as belonging to a "Marxist orginisation".
  10. The Inconvenient Skeptic at 20:07 PM on 2 March 2011
    Climate Sensitivity: The Skeptic Endgame
    Kevin,

    I have plenty of annual data, but imagine if I tried to interpolate monthly data with the annual variation included. In addition I strongly doubt that accuracy of the CO2 data you linked between 1937-1950. I struggle with the idea that there was no increase in CO2 during that period. There was enormous production during that period with massive quantities of CO2 released. Every production facility in the world was working at maximum capacity for portions of that time.

    I do appreciate the link though.

    Insolation changes over the past 100 years should be warming the winters and reducing the temperature difference between the poles and the equator as the tilt is very slowly decreasing.
  11. Climate Sensitivity: The Skeptic Endgame
    Huggy Pops bear #2

    A definitive answer is impossible as you cant put the planet in a laboratory. Its really that simple. All you can get is probabilities. Modelling is a substitute for not being able to put the planet in the lab. Its frustrating but thats the reality, and you just have to live with it or risk the ruin of the planet.
  12. Dikran Marsupial at 19:55 PM on 2 March 2011
    Prudent Risk
    RSVP@23 No, of course I am not saying that. Some ecological niches require longevity to fully exploit, so fitness for a particular environment/niche is a compromise of many factors, longevity and evolutionary adaptability are only two of them.

    We don't need to use evolution as a measure of environmental change, there is plenty of direct evidence that the environment changes. We all know that, and it is entirely uncontraversial.

    BTW, if we lived forever, there would be no evolutionary adaption to viral and microbial pathogens (which don't live forever). So even if the environment were unchanging, we would not survive as a species if we lived forever, so your argument isn't even logically consistent.
  13. Roy Spencer’s Great Blunder, Part 2
    Im intrigued about this claim that natural causes havent been investigated. I have just waded through the summaries on sceptical.science.com of 20 odd papers on the affects of the sun, and read some of the originals, and I still have a headache from it all as my maths is rusty. Did I hallucinate all that? Isnts 20 papers enough? How many does Mr Spencer want? What planet does he live on?
  14. Climate Sensitivity: The Skeptic Endgame
    I have some trouble with the concept of "unique" "equilibrium sensitivity" : if there were such a quantity, shouldn't the average global temperature follow very closely (within a relaxation timescale, which is supposed to be short if the current 30-years increase is supposed to be linked with an increase of radiative forcing) the global forcing ? so shouldn't we expect the temperature curve to closely follow, for instance, the milankovitch cycles? well, there is an obvious correlation with astronomical parameters, but nothing very close to them. Why ?
  15. Climate Sensitivity: The Skeptic Endgame
    Incovenient Skeptic: Here is a table of annual CO2 levels from 1800, with 50 year values back to 1000: Link.

    It also gives CH4 levels. If you need monthly values, then interpolation (with an annual profile superimposed if necessary) should give you a good estimate. I could help you in preparing such a file.

    However as you know if you want to attribute temperature changes over the 19th/20th century you don't just need CO2 and CH4 - you will also want to take into account the variation in insolation (and possibly aerosols).
  16. Climate Sensitivity: The Skeptic Endgame
    HuugyPopsBear #2,

    The relationship beween CO2 and global warming is not solely based on modeling. The equations connecting CO2 and IR radiation hve been well understood and dmeonstrated for many years. They form the basis for the operation of devices like CO2 lasers and air-to-air heat-seeking missiles. If the rise in CO2 in the atmosphere had NOT been accompanied by temperature rise, physicists would be questioning thir understanding of basic radiation physics.

    If you search the Skeptics Arguments you will find answers to your points on CO2 lagging temperature, and CO2 as a plant food.
  17. The Inconvenient Skeptic at 18:38 PM on 2 March 2011
    Climate Sensitivity: The Skeptic Endgame
    Bern,
    If you have CO2 monthly data earlier than March of 1958 I will gladly use it, but since it was 315 ppm in March of 1958 and the previous 50 years prior to that showed little CO2 increase it is a safe to assume that the rate of CO2 increase prior to 1958 is lower than since then.

    As for the temperatures, if I use your same source, the period from 1908-1958 shows more warming than the years I used and clearly the CO2 was not increasing at the same rate.

    If you are arguing that the CO2 increase from 305 to 310 caused more warming than the jump from 310 to 360, that is a different argument though.
  18. Prudent Risk
    Marcus #22, Dikran Marsupial #19
    "the only reason viruses, bacteria & insects develop such rapid resistance is because of their extremely short life-cycles-which allows for the rapid accumulation of genetic mutations"

    So you are saying then that a short life span favors survival of the species. If so, animal kingdom life span is a proxy for environmental stability, and the fact that we dont live forever (and have "evolved") means the Earths environment has always been changing. I thought evolution was a good thing? Please clarify.
  19. Climate Sensitivity: The Skeptic Endgame
    Oh, and nice article, Dana - well written & clear.

    I think it illustrates well that the 'skeptic' position re sensitivity is a very weak one, at best.
  20. Climate Sensitivity: The Skeptic Endgame
    I'm sure others will address some of the other issues in the comments above, but I'd like to address this one:

    "no significant trend in global temperature from the 1958-1995"

    Well, TIS, this graph [woodfortrees.org] suggests there's been plenty of warming from 1958-1995.
    It's even more interesting when you increase the time range to 1955-2000. You get to see that 1958 was a particularly warm year, for the 1950s, and that 1995 was an average-to-cool year for the 1990s. Has there been some cherry picking going on?
  21. The Inconvenient Skeptic at 17:49 PM on 2 March 2011
    Climate Sensitivity: The Skeptic Endgame

    Since CO2 levels were 310 ppm in 1950. It was only after 1960 that the CO2 levels started to significantly increase. The claim that warming prior to the increase in CO2 levels is caused by CO2 levels is incoherent. Since more than half of the warming in the past century took place before 1950 I see a flaw in your argument that CO2 has caused all the warming. There was also no significant trend in global temperature from the 1958-1995 while CO2 levels in the same period increased from 310-360ppm. The early date is used only because that is the start of reliable CO2 data. http://theinconvenientskeptic.com/wp-content/uploads/2011/03/CO2-1958-1996.png No temperature trend for almost 40 years while CO2 was climbing. There was significant warming after the 1998 El Nino and there was warming in the 1930's when CO2 was low and stable. But the period that showed the most change in CO2 did not show warming. That shows an interestingly low climate sensitivity to CO2.

    Response:

    [dana1981] First of all, the global average surface temperature has increased 0.8°C over the past century, and almost 0.6°C since 1970.  So the claim that "more than half of the warming in the past century took place before 1950" is factually incorrect.  As the link above shows, the claim of "no significant trend in global temperature from the 1958-1995" is also factually incorrect.

    Unfortunately these factually incorrect statements led you to an incorrect conclusion.

  22. Roy Spencer’s Great Blunder, Part 2
    Responding to (3), (7), and (11)... I concur that the tone of SkepticalScience has been and continues to be exemplary -- all credit to John Cook who has created something truly valaubel here.

    However... I do think we need to concede something of a special case in the case of Roy Spencer and his book. Roy has -- on his blog, in numerous public talks (one of which I witnessed personally) and now in his book -- not only put forth scientific arguments, but also directly accused his colleagues of deliberate malfeasance ["I find it difficult to believe that I am the first researcher to figure out what I describe in this book. Either I am smarter than the rest of the world’s climate scientists–which seems unlikely–or there are other scientists who also have evidence that global warming could be mostly natural, but have been hiding it. That is a serious charge, I know, but it is a conclusion that is difficult for me to avoid." (p. xxvii)]

    I fully concur that our primary purpose here must be to improve understanding, and of course that involves taking a tone that does not immediately put off those who are resistant to the information. However, in addition to clear exposition of the science, I think it's also important to help folks understand that there are people like Roy out there exhibiting a level of obtuseness over decades. Roy's work, as I believe Dr. Bickmore and others have demonstrated, is simply not intellectually honest. If one needs to be a bit more direct in making that point, I think in this case it's warranted -- and indeed beneficial to effective communication. I think Dr. Bickmore has successfully walked a very fine line.
  23. gallopingcamel at 17:12 PM on 2 March 2011
    Visualizing a History of CO2
    Loved the music. Scientifically, why not include the "Big Picture"?

    http://www.scotese.com/climate.htm
  24. HuggyPopsBear at 17:03 PM on 2 March 2011
    Climate Sensitivity: The Skeptic Endgame
    Sorry did not finish. Or is it a fact and not a probability. I recognize pollution is a problem of mankind and something needs to be done, but CO2 is not necessarily a pollutant as it has many benefits for sustaining life and plant growth.
    Moderator Response: See "CO2 is not a pollutant," and comment further there, not here.
  25. HuggyPopsBear at 16:59 PM on 2 March 2011
    Climate Sensitivity: The Skeptic Endgame
    Since being on this site and reading all the bits and pieces coming up, everything reads that CO2 is forcing global warming. Mostly from modeling which can only translate data put in by human effort. It cannot predict with infinite reliability future events as nothing is constant. I have always been of the belief that CO2 increase was a direct result of warming, hence why Co2 has continued to increase for a period when cooling came into operation.

    Once land masses were refrozen then the CO2 would drop and continue to drop even when warming again began to increase. So surely there must be another factor that is not being factored into the equation or modeling?

    Why can neither side come up with a definitive answer that would satisfy the masses and destroy governments greed for wanting to tax a probability.
    Moderator Response: Then you need to read more than "bits and pieces." Start with "Models are unreliable," "CO2 lags temperature," "There’s no correlation between CO2 and temperature," "CO2 is not the only driver of climate," and "The science isn’t settled."
  26. Climate Sensitivity: The Skeptic Endgame
    Thank you so much for referring to "skeptics" in quotes. They act like purposefully cultivated disinformation campaigners. But so called "skeptics" says it OK.

    But none-the-less, by addressing the specifics of the science issues - you do a great service. Thank you.
  27. Crux of a Core, Part 1 - addressing J Storrs Hall
    Rob Honeycutt -- I'm trying to understand your article. In particular, I'm trying to figure out the source of your Figure 1, with your caption of "GISP2 as presented on Watts Up With That, conflating a local record with a global record."

    The only source I have found for that is the link you provided, http://wattsupwiththat.files.wordpress.com/2009/12/noaa_gisp2_icecore_anim_hi-def3.gif

    In that link, however, the chart is clearly labeled "Data Source: GISP2 Ice Core, Central Greenland".

    It seems like you removed the "Central Greenland" label, and then accused Watts of conflating local and global records. Did you indeed do this?

    Please identify the source of your Figure 1, so your readers can judge for themselves what sort of conflation is going on.

    The other WUWT link you provided also very clearly talks about this being for 1 point on the earth.
  28. Roy Spencer’s Great Blunder, Part 2
    Peter Offenhartz @26, the blue plot on the graph (CO2) is just the radiance spectrum for 287 ppm CO2 - that for 584 ppm. The area under the blue curve is then change in forcing for that change in CO2 concentration.

    If you compare wavelengths on that diagram with the wavelengths with the diagram linked by KR, you will see that 15 microns lines up with the center of the main trough produced by CO2 in the spectrum. The two large peaks at approximately 13.5 and 16.5 microns on the diagram I posted then line up with the "wings" of the CO2 trough.

    Here is that KR's linked image for easy comparison. You will notice the wave lengths are marked along the top of the diagram.

  29. Roy Spencer’s Great Blunder, Part 2
    HR:

    So far you have managed to skillfully avoid it.

    This seems uncomfortably close to an accusation of dishonesty.

    In some respects this is part of the problem with the plethora of recent 'skeptic bashing' articles on this website. It's more concerned with point scoring and discrediting the individuals than it is about understanding their concerns.

    That's an odd thing to say. Surely concerns should be based on hypotheses and data that can withstand critical scrutiny? And if they aren't, surely that says something about their validity?

    Some "skeptics," when confronted with errors they can't defend, resort to insinuating that their opponents are wrong in some obscure moral sense, despite being correct on the facts (e.g., they're "point scoring," which is somehow shabby and disreputable). I hope you're not trying to take that approach here.
  30. Peter Offenhartz at 15:16 PM on 2 March 2011
    Roy Spencer’s Great Blunder, Part 2
    @apsmith (19) I'm afraid I have to agree with Tom Curtis (20). It is possible to assign a temperature to a specific wavelength/frequency. As for the central spike in the CO2 absorption, that simply reflects a different temperature/altitude for that particular wavelength region. One cannot assign a uniform temperature for a broad band, and the T^4 rule applies always. not just to the overall integral. But that's an awfully small point. The main point I was trying to make is that if the temperature/altitude point for the main-band CO2 upwards emission lies at an altitude that coincides with the knee of the lapse rate (as it apparently does), rising CO2 concentrations won't affect global warming. But the wings will.

    As for Tom Curtis (18), I will have to take a look at your references (I find the graphic you provided confusing), and I will try to find time to get back to you. But I doubt that increasing CO2 concentrations can affect the emission temperature at the center of the CO2 absorption band. But the wings (and maybe even that blip in the middle of the band) surely are important. Thanks for your help. I think I am learning!
  31. Crux of a Core, Part 1 - addressing J Storrs Hall
    scadenp says "Charlie A, put your serious skeptical hat on and closely read that post yourself. Spot the switch from absolute to anomaly?"

    OK. I followed the link in top of this Skeptical Science post over to the WUWT post Hockey Stick Observed in NOAA Ice Core Data.

    I see the ice core O18 isotope ratio data described as "It gives us about as close as we can come to a direct, experimental measurement of temperature at that one spot for the past 50,000 years." That sounds like a reasonable description.

    Hmmm. Perhaps the article here on SkepticalScience is tilting at windmills are strawmen.

    OK. Then there are a series of graphs for the central Greenland Ice core data. Varying lengths of record are looked at, but they are ALL in plots of estimated temperatures. The maximum length of data for that ice core is plotted.

    He then says "This next graph, for the longest period, we have to go to an Antarctic core (Vostok):" and shows that graph of temperatures. This one in with vertical axis being the temperature anomaly. The graph covers the entire period.

    Do you have some problem with using a plot of temperature anomoly when switching to another location?

    Why does that present a problem? Adding in a fixed offset to all of the graphs for the central greenland ice core would not, IMO, make any difference in the presentation.
  32. Roy Spencer’s Great Blunder, Part 2
    apsmith @22, great blog post, and your fourth figure illustrates very well your claim about the Planck function.

    As indicated, I wasn't sure you were disagreeing with anything. I was just uncertain as to why you thought it important to mention the Planck Function in this context.
  33. actually thoughtful at 14:45 PM on 2 March 2011
    Roy Spencer’s Great Blunder, Part 2
    HR - I would be more inclined to agree with your criticism if Spencer didn't try to poke holes in the Milankovitch cycle theory. Given that he did, I think it is fair to critique his argument against Milankovitch cycles.

    I think the idea that there is a 60 year, 1,000 year, etc cycle has some problems, one of which is we are 40 years into a 60 year "cycle" - the sun is about to end its quiescence and while it is theoretically possible, it is highly doubtful that the next 20 years will show any cooling. So that blows up the 60 year cycle. The data for longer term, non-Milankovitch cycles is even weaker.

    I think Spencer is essentially looking for a miracle in the 5% probability that the IPCC leaves on their predictions.

    So in the sense that anything is possible - sure. In the sense that we have a pretty good understanding of the climate system, and at this point studies are confirming model-predicted behavior, not so much.
    ____________
    Kevin C @ # 3 - excellent comment. Very well said and I agree. I was squirming in my chair, realizing the analysis was pretty good, but the tone is not up to SKS standards.
  34. michael sweet at 14:33 PM on 2 March 2011
    Roy Spencer’s Great Blunder, Part 2
    Moderator,
    I agree with from Peru that Roy Spencers anti scientific ideas about Evolution and Creation cast doubt on his scientific judgement. I do not like the suggestion of ad-hominem at #6. Can you suggest what is appropriate on this site in this situation so that I know for future reference? Thank you for your help.
    Moderator Response: [Dikran Marsipial] The Comments policy explicitly forbids ad-hominem attacks, which are an attack on the source, rather than the content of an argument. Dr Spencers views on evolution have no bearing on whether his theories on climate are correct or not, and they should stand or fall on their own merits. Several contributors to Skeptical Science are committed Christians (and other faiths), including myself, there are plenty who would say that such views are unscientific (I would agree) and/or delusional (I don't agree there ;o). Does that mean skeptics can dismiss any of my arguments on the basis that I have religious beliefs? It is a slippery slope, and it is part of the distinctive nature of Skeptical Science that the discussion is centered on the science and logical fallacies such as the ad-hominem are discouraged, it is one of the features that makes Skeptical Science (in my view) the best of the climate discussion forums. Note that Spencer has frequently refuted other skeptic arguments, such as that CO2 is not a greenhouse gas, that the greenhouse effect contradicts the second law of thermodynamics, or demonstrating that the results of Lindzen and CHoi were substantially flawed. Are those arguments devalued by doubt on his scientific judgement? No, their value is determined by their internal consistency and support from the data and experiments.
  35. Roy Spencer’s Great Blunder, Part 2
    Tom (@20) - I don't think we're disagreeing, I recently blogged on the subject of the temperature associated with emission to space. My only point was the Planck function for a given wavelength is not proportional to T^4, only the integral over all wavelengths is.
  36. Australia's departing Chief Scientist on climate change
    I hope you are wrong. I think we need to leave thermal coal in the ground and get energy elsewhere. However, making steel without coking coal is challenging. Surely the climate can cope with steel emissions provided other CO2 source are brought down?
  37. CO2 lags temperature
    287: Bruce,

    A couple of misconceptions in your comment: CO2 is not the only driver of climate. It happens to be a strong positive forcing now; that does not mean it always was.

    Oceans are acidifying, meaning they are absorbing CO2 from the atmosphere. At some point (or perhaps at some locations) they will warm sufficiently to release dissolved CO2.

    As always, the picture is more complicated than one can sum up in a sentence or two.

    There is a wealth of information here at SkS designed to inform and dispel some of the myths, half-truths and outright distortions that kick around the internet. Use the Search function to browse the most commonly heard 'skeptic arguments.'
  38. michael sweet at 14:18 PM on 2 March 2011
    Australia's departing Chief Scientist on climate change
    In order to deal with the AGW problem the world needs to leave all the rest of the coal in the ground. When politicians realize that it is cheaper to leave the coal in the ground than to pay to rebuild after floods, like this years in Queensland, than something may be done. The developed world will have to lead before the developing world will follow. It is too bad that Australia has such a dependence on coal. They will have to find new sources of revenue. Hopefully they will not wait until AGW has destroyed their agriculture base before the change is made. If they wait that long it will be even more difficult to adjust. Right now the deniers are succeeding in delaying any action.
  39. Measuring CO2 levels from the volcano at Mauna Loa
    Nice non-technical summary article on the history of atmospheric CO2 measurements at climatecentral.

    The Mauna Loa volcano rises high above the Pacific on the Island of Hawaii. “Here, the background concentration of carbon dioxide should not be influenced by forests or soils, or an inversion or the weather,” Tans says. “All that is stripped away.”
  40. CO2 lags temperature
    A positive feedback does not necessarily mean runaway feedback. See run away warming
  41. Crux of a Core, Part 1 - addressing J Storrs Hall
    Thanks for that Tom. I had an unkind thought about how often certain people deign to put "Dr" before many well-known names.

    And "...greenhouse warming is not an unusual explanation... any change of climate needs some explanation." You're right. Far too many people of this ilk talk about global warming "theory" as if it were some discrete academic discipline. "Global warming" is just a sub-set of general climate science.

    Climate science shows that certain events and circumstances have predictable outcomes. The current circumstance, of releasing an unusual amount of GHGs at an unusually fast rate, is displaying fairly predictable responses. Usually called global warming. Those responses being in accordance with the general theory mean that we have a fairly high level of confidence that events in the future will unfold in accordance with the theory.

    More data, better technology, more experience working with the information we've already accumulated just makes it less and less likely that current evaluations of the historical record and any consequential projections for the near or distant future will turn out to be "poppycock".
  42. Bruce Frykman at 13:55 PM on 2 March 2011
    CO2 lags temperature
    Since we have accepted the fact that atmospheric CO2 concentration is a primary driver of the earth's climate and also the fact the the earth has been much warmer in the past this presents a dilemma.

    The oceans contain about 50 times more carbon dioxide than does the atmosphere. It has been well noted that warming oceans release more of their absorbed carbon dioxide than they at the same time sink from the atmosphere.

    So remembering that atmospheric carbon dioxide concentrations are the primary driver of our climate any previous warming in excess of what we see in modern times should have driven a runaway warming cycle, driven by massive releases of oceanic carbon dioxide in a positive feedback loop.

    But somehow this didn't happen. I wonder why?
  43. HumanityRules at 13:30 PM on 2 March 2011
    Roy Spencer’s Great Blunder, Part 2
    bbickmore,

    I think you're being a little disengenuous or atleast knit-picking here. I think you know that he thinks that multi-decadal to centennial natural variation are ignored by the IPCC. Technically your right in what you're saying, and sure you've highlighted some sloppiness in some out-of-context sentances but why use the example of millions of years cycles to criticism like this "...on time scales of thirty years or more...". I think to provide a substantive critique of Spencer you should be showing the solidity of the understanding of multi-decadal change. So far you have managed to skillfully avoid it.

    In some respects this is part of the problem with the plethora of recent 'skeptic bashing' articles on this website. It's more concerned with point scoring and discrediting the individuals than it is about understanding their concerns.
  44. Crux of a Core, Part 1 - addressing J Storrs Hall
    Charlie A @31, first let me second scaddenp's comment which is exactly to the point.

    Let me add, first, that Hall feeling slighted about not being called "Dr" is extraordinarily precious from somebody who dismisses climate scientists as "The Hockey Team" and dismisses (his straw man version of) their theories as "poppycock".

    More substantively, it is very noticeable that when he compares Antarctic and Greenland ice cores, he does so over the period of the Last Glacial Maximum. Unsurprisingly, there is a correlation between temperature differences between the LGM and the Holocene (the last 10 thousand years). But even during the last glacial there are clear anti-correlations between the three ice cores, even between the two Greenland ice cores on a scale of thousands of years. Therefore his failure to show a comparison of GISP2 and Vostok over the period of the Holocene with sufficient resolution is very damming.

    Such a comparison can be made in Figure 3 above. Vostock is shown in Dark Blue, GISP2 in light blue. If you look closely you will see that they are anti-correlated for most of the holocene. That means their average will have far fewer and smaller fluctuations then either seperately. The rapid rises and declines in the Greenland ice core during the Holocene are not global events, but the equivalently precipitous rise in late twentieth century temperatures is.

    Finally, he claims "The 20th-century warming was hardly unprecedented, and doesn’t call for unusual explanations." Let's leave aside that greenhouse warming is not an unusual explanation. The fact of the matter is that any change of climate needs some explanation. For global temperatures to change by up to a degree or more without explanation would violate conservation of energy. As it happens, the only substantive explanation is anthropogenic emissions of Green House Gases.

    (On a side note, Hall's PhD is in "computer science", which may well make him a skilled programmer, but it does not make him a scientist despite his claims.)
  45. Roy Spencer’s Great Blunder, Part 2
    apsmith @19, I'm curious as to why you bring up the Planck function. I don't doubt what you say, but it does not mean you cannot judge temperatures of gases from the relative intensity of their emission spectra at a give wavelength relative to the intensity predicted by a black body curve.

    Thus, in your illustration, and ignoring complexities related to emissivity, we can see the surface temperature was less than 275 K, and hence close to freezing. We can also see that the average temperature of CO2 molecules emitting to space was around 223 K at that location. That is what Peter was doing, and quite correctly.

    In fact, physicists often do the same thing more formally by plotting the spectrum as brightness temperature against wavelength instead of radiance against wavelength. One example (from here) is this plot, clearly from a tropical sounding:

  46. Australia's departing Chief Scientist on climate change
    michael sweet #13

    My points are simple ones. The Australian economy relies on coal and iron ore exports for a large chunk of its export income. The Federal Govt counts on this income and the taxes raised therefrom to run its budget - and so do State Govts in Qld and NSW.

    Our own carbon emissions are a tiny fraction of what carbon we export to China, Japan, Korea, India, Taiwan and other emitters.

    There is a massive contradiction in a Federal Govt imposing a carbon tax on Australians for negligible real effect on global CO2 emissions, while depending on and factoring in the income from increasing coal exports.

    Some would call it breathtaking hypocrisy.
  47. Roy Spencer’s Great Blunder, Part 2
    Peter, regarding the very center of CO2 absorption, you should take a close look at a graph of the measured outgoing spectrum from Earth, for example this one posted at ScienceOfDoom here - http://scienceofdoom.com/2010/05/12/co2-an-insignificant-trace-gas-part-eight-saturation/



    You'll notice that right at the center of the 15 micron dip there's a narrow spike. That higher level of emission right in the center of the absorption band is from the warmer temperatures in the stratosphere, just as you guessed. But the dependence is not the T^4 rule, that applies only to the overall integral of emission over all wavelengths. The specific law for a single wavelength is the Planck function, which is roughly linear in temperature for high temperatures, but drops very quickly to zero at low temperatures.
  48. Crux of a Core, Part 1 - addressing J Storrs Hall
    Charlie A, put your serious skeptical hat on and closely read that post yourself. Spot the switch from absolute to anomaly? Perhaps read the papers instead of the quotes.

    As for "the only substantive point was..". Ho, ho.

    The zero point of 1855 isnt a substantive point? The actual temperature measurements? Does the original article still make sense when you look at the correct construction. (eg in #14 )
  49. Philippe Chantreau at 12:26 PM on 2 March 2011
    Crux of a Core, Part 1 - addressing J Storrs Hall
    "The author of the post being rebutted, J Storrs Hall, has taken exception to not being addressed as doctor and feels this is a deliberate slight upon him."

    Funny. I have read so many skeptic rants about appeal to authority, use of titles to suggest authority, how one does not need degrees to be qualified, what an expert is, etc. I had construed that skeptics did not care much about academic titles. Silly me.
  50. Roy Spencer’s Great Blunder, Part 2
    Peter Offenhartz @17, you may well be interested in the post on Theory and Experimant at Science of Doom. It contains (amongst other gems) this illustration of the effect of doubling CO2 on radiative forcing:



    As you can see, most of the effect is in the wings of the 15 micron trough, although there is a slight deepening of the trough in the center, which is the second largest effect. Some other absorption bands currently barely detectable in atmospheric spectrums also start to strengthen.

    This is the non-equilibrium response. As the Earth warms to restore equilibrium, there will be an increase in radiation at all frequencies, so that in the equilbrium case, there would be more radiation from the center of the 15 micron band, not less.

    Although KR has found mention of 215 K as the brightness temperature at the center of the 15 micron band, I have noticed it as being centered around 220 K, with tropical spectra above that, and polar spectra below.

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