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Comments 125401 to 125450:

  1. 2009 - 2nd hottest year on record while sun is coolest in a century
    " Of more significance is the long term trend " Why didn't you just put single trend line for the whole time period for both temp and TSI (I've seen it done for temp before). That would show TSI going up since 1880 and temp going up since 1880. What could we draw from that?
  2. 2009 - 2nd hottest year on record while sun is coolest in a century
    Skeptics have long pointed out that atmospheric CO2 rise is a near perfect linear rise over the century while global temperatures have seen periods of rise, leveling and decline (as seen on your graph). If you also posted CO2 levels on the graph in figure 1 you could just as easily argue that the CO2 and global temperature graphs look unrelated in the period of 1940-1970 when temperatures where declining or steady.
    Response: The issue of mid-century cooling is addressed here. The basic point is there is not a single driver of climate - you need to take into account all forcings: sun, volcanoes, CO2, sulfate aerosols, etc. The same point applies to this page - sun is the not the only driver of climate and that becomes apparent when global temperatures rise during a period of cooling sun. Obviously some other forcing other than solar variations is driving the warming.
  3. Berényi Péter at 03:13 AM on 20 January 2010
    Skeptical Science now an iPhone app
    Listen. If instrument quality is in doubt, the first thing a sane person does is to check the instruments themselves (as opposed to the arcane statistical properties of datasets collected by these instruments). The WMO intercomparision did exactly that. First in the lab, then there was also an extensive field test involving balloons. The important lesson learned is NOT "you get large variabilities". It is the exact nature of the variability that counts. They have found that below the 300 hPa level (for sure below 400 hPa) the humidity response of each instrument was consistently monotonic with a low enough random noise. Not necessarily linear, but monotonic. The large (up to 10%) variability was observed between different instrument types, not in the performance of a single instrument. The other issue was the different and temperaure dependent relaxation times of various types of instruments. But it was measured, documented and it is also deterministic. Now, if you have the description of instrument behaviour for each type along with time stamps, pressure and temperature data (even better to have the values for both ascent and descent), these errors are easy to eliminate. One does not even have to be a climate scientist to do that. I myself could perform the correction. I just do not know if the job was done or not. If it was done, there still remains some uncertainity. You have reffered to it as "when you actually fly a baloon there's much more than that". Actually not much more. There may be solar radiation acting on the case, water or ice can get inside due to precipitation and/or condensation, finally some random noise which is always present in any measurement. However, all these combined have much less effect than the difference between instrument classes, certainly less than the magnitude of the three decade trend. Moreover, these effects can not possibly have a definite trend over a multi decadal time scale. When I have drawn my conclusion, I assumed the trivial recalibration job I have described above is already done. If it is not, now, that's travesty.
  4. Two attempts to blame global warming on volcanoes
    Ned. Your post 25 is one of the best, as it actually points to the way forward. If we all did just stay in bed, maybe the environment would have hald a chance.
  5. Two attempts to blame global warming on volcanoes
    Marcus, There appears to be a small flaw in your reasoning #28. If global warming in NOT anthropogenic, it would suggest there is not a lot we can do about it. Yes, we can prepare for it, but we cant change it. One of the most irresponsible notions I have seen on this website come from those who are not willing to place the blame on overpopulation, especially when they support the theory that global warming is anthropogenic. If it is anthropogenic, it is because there are just too many anthropoids!
  6. Two attempts to blame global warming on volcanoes
    Thanks a lot, Chris. Very helpful.
  7. Two attempts to blame global warming on volcanoes
    Another point, RSVP, is that if CO2 is not the real culprit, then this actually provides a whole new mystery for climate scientists to solve, thus giving them *loads* to do-both in determining the real culprit & trying to model the impacts of this new cause on future climate change. Indeed, a new culprit for climate change might require *more* scientists, not less, to pore over all the existing literature to try & get a handle on the real culprit. Second to this is that climate scientists existed before global warming became an issue, & would still exist if the whole thing proved to be a furphy, so your whole argument is really quite weak!
  8. Two attempts to blame global warming on volcanoes
    By the same token, RSVP, if CO2 is the real culprit (as all the evidence seems to suggest), then reducing CO2 emissions will require significant cuts in our use of fossil fuels-which will in turn hurt the profits of the companies that mine & refine these fossil fuels. Is it any wonder, then, that a great deal of the anti-AGW bias is coming from individuals & groups with such strong links to the fossil fuel industry?
  9. Two attempts to blame global warming on volcanoes
    Ned, Actually what you are trying to say is that if CO2 is no the real culprit, climate scientists have nothing to do. And therein lies the bias.
  10. Two attempts to blame global warming on volcanoes
    RSVP writes: Even if the current trend in global warming is actually anthropogenic, (and due solely to CO2 emissions), all it takes is one huge natural disturbance, or change on the part of nature to make anthropogenic forcing completely irrelevant (at least for a time). So? Even if you've saved up scrupulously for retirement, a large comet hitting the Earth would wreck the economy and eliminate your retirement savings. So there's no point in saving for retirement. Seriously, what is your point? As far as I can tell, every single one of your dozens of posts here consists of rather transparent attempts to justify not doing anything serious about reducing our impact on the climate system. But this one just seems ridiculous. We shouldn't bother doing anything to reduce our CO2 emissions because some mysterious catastrophe could happen suddenly and render all our work irrelevant? That logic could be used to argue against doing anything about anything. Why bother getting out of bed in the morning, when you could be hit by a streetcar on the way to work?
  11. Skeptical Science now an iPhone app
    Berényi Péter, the WMO intercomparison pubblication you quote is a lab test of different sensors, not field data. It assess the difficulties of the humidity readings even in controlled conditions and still you get large variabilities especially at low temperatures. When you actually fly a baloon there's much more than that. I don't want to mean that we have to discard radiosonde data, they are a piece of the puzzle. But given the large uncertainties, the small trend (a few percent) and the disagreement with satellite data, I (with Paltridge et al.) would not draw any strong conclusion, let alone claims like "Water vapor feedback in terrestrial photosphere is negative. It is as simple as that."
  12. Two attempts to blame global warming on volcanoes
    Even if the current trend in global warming is actually anthropogenic, (and due solely to CO2 emissions), all it takes is one huge natural disturbance, or change on the part of nature to make anthropogenic forcing completely irrelevant (at least for a time). Or is this not conceivable? On the other hand, as per chris #22, even if the Earths temperature did rise 10 degrees for 500 years due to a comet, you would still have to baseline the problem from the new mean, and consider only extra forcings due to CO2 and sunlight. In other words, Paz, it doesnt matter how much heat is coming from the bottom of the sea due to hotspots and fissures.
    Response: Man-made warming is not due to CO2 emissions only - there are also warming contributions from ozone, methane, contrails, nitrous oxide, CFCs. But the warming from CO2 is both the strongest forcing and the fastest rising.
  13. Berényi Péter at 11:53 AM on 19 January 2010
    Skeptical Science now an iPhone app
    Riccardo at 22:56 PM on 17 January, 2010: "You will easily find a lot of papers on the dry bias and possible recalibration of radiosonde data" No, not easily. I have fond something though. INSTRUMENTS AND OBSERVING METHODS REPORT No. 85 WMO RADIOSONDE HUMIDITY SENSOR INTERCOMPARISON PHASE I: Laboratory Test Central Aerological Observatory Dolgoprudny, Russian Federation June 1995 - June 1997 A. Balagurov, A. Kats, N. Krestyannikova (Russian Federation) PHASE II: Field Test NASA Wallops Flight Facility Virginia, United States 8 - 26 September 1995 F. Schmidlin (United States) WMO/TD-No. 1305 2006 http://www.wmo.int/pages/prog/www/IMOP/publications/IOM-85_RSO-RH-Phase_I-II/IOM-85_RsoHumiditySensors_Phase-I-II.pdf The analysis is thorough. And it was performed in 1995-97. More than ten years ago. I don't quite understand why was it published only in 2006. It should be enough to do the instrument recalibration job up to the 300 hPa level, verifying the long term humidity trend up there this way. I can see the NCEP/NCAR Reanalysis is going on. http://www.cgd.ucar.edu/cas/guide/Data/ncep-ncar_reanalysis.html However, I was not able to find reference to the WMO Radiosonde Humidity Sensor Intercomparision, which would be an absolute must. It may be my fault, a briefing would be welcome. So the NCEP reanalysis dataset is either uncorrected for known instrumental biases or Paltridge, Arking & Pook have revealed a gaping hole in current theory which is based on constant RH above 850 hPa. In the first case your statement "many scientists around the world are still working on this issue" lacks credibility. A job like this taking more than ten years to be done properly is flagrancy itself. Otherwise the average climate model is falsified. Water vapor feedback in terrestrial photosphere is negative. It is as simple as that. As for surfacestations.org. You know full well the quality of individual stations (or the lack of it) is not documented nearly as well in reanalysis studies as by those volunteers. One would wish for such a check on a global scale. http://www.ncdc.noaa.gov/crn/ "The vision of the USCRN program is to maintain a sustainable high-quality climate observation network that 50 years from now can with the highest degree of confidence answer the question: How has the climate of the nation changed over the past 50 years?" "Fifty years from now". Rather forty three in 2010, as the US Climate Reference Network (with some long term quality control) was started in 2003. Need say more? Surfacestations is checking USHCN (United States Historical Climatology Network), which is an entirely different beast. http://www.ncdc.noaa.gov/oa/climate/research/ushcn/ushcn.html NCDC guys are cross-checking neighboring station data, read (incomplete) station history files and do all kinds of statistical tricks, but no one goes there to have a look for the sake of good old reality check.
  14. Two attempts to blame global warming on volcanoes
    re the TP Barnett et al paper in my post #19 above. The url corrupts when pasted here (perhaps John Cook can fix it!). You can find the downloadable pdf by Googling using the search term: Penetration of human-induced warming into the world's oceans. Barnett TP The link to the pdf will be high up on the list of results...
    Response: I've fixed the link in Comment #19. What I think happened was you copied and pasted the URL from the google search results. The problem is google abbreviate the URLs that they display in the search results (hence the /../ peppered through the URL). You need to click on the link then copy and paste the full URL from the browser's URL bar.

    BTW, thanks for posting that paper. When I get around to the "heat from underwater volcanoes are causing global warming" argument, Barnett et al is a key part of the answer.
  15. Two attempts to blame global warming on volcanoes
    re #12 From Peru The apparent dichotomy of the apparently quite sizeable geothermal heat flux (0.09 W/m^2) compared to the radiative forcing from CO2 (0.9 w/m^2) is resolved by noticing that the geothermal flux isn't a forcing. The geothermal flux is the background stationary level of heat flow from the interior, and since this has been proceeding for millenia and more into the deep past, the earth's ocean/surface temperatures will be near equilibrium with respect to the geothermal flux (unless it has changed massively in reecent times). So the forcing is near zero. It would be more appropriate to compare the geothermal flux (0.09 W/m^2) to the total solar flux averaged over the earth surface (1370/4 W/m^2).
  16. Two attempts to blame global warming on volcanoes
    a few minutes too late, and chris's answer is more detailed ;)
  17. Two attempts to blame global warming on volcanoes
    From Peru, on a geological time scale even land volcanoes may have a role, as probably happened in the deep past and on a much smaller scale in the last century. But it's irrelevant for recent global warming, what matters is what changes, not what is constant. One more point, as Gavin Schmidt said a while ago answering a question, underwater volcanoes would warm the deep ocean more than the surface, which is not happening.
  18. Two attempts to blame global warming on volcanoes
    Another way of addressing your question Paz, is to examine the vertical distribution of enhanced ocean heat in a warming world. The time variation of enhanced heat will be quite different if the heat penetrates the ocean from the atmosphere, compared to the notional situation of enhanced undersea volcanic activity (a notion which completely lacks evidence - one would have to postulate that undersea volcanic activity has all of a sudden increased by a truly vast amount). There's a fair amount of analysis of enhanced ocean heat distribution, and this is consistent with ocean warming as a result of heat penetration from the atmosphere. A "classic" paper is this one, downloadable from the link below (there's quite a bit of more recent studies too...): Barnett, T. P. et al. (2005) Penetration of Human-Induced Warming into the World's Oceans Science 309, 284-287
  19. Two attempts to blame global warming on volcanoes
    Sorry, Paz, I don't remember. Look at the comment I cross-referenced earlier, and click on the links you find there; they might have what you're looking for. Otherwise I suggest looking at the U.S. Geological Survey web site.
  20. Two attempts to blame global warming on volcanoes
    From Peru, the forcing from solar minimum and solar maximum is zero. Because the min and max cancel each other out, over every 11 years. And geological timescales are irrelevant to the past 150 years in which human-induced warming has been most pronounced.
  21. Two attempts to blame global warming on volcanoes
    From Peru, I got the data from the sources I listed in the comments I cross-referenced in my previous comment. Where I wrote "For details, see ....". You should read first, type second.
  22. Two attempts to blame global warming on volcanoes
    Thanks Tom, very interesting. Do you know of any charts that track recent the amount of underwater volcano eruptions over the recent decades?
  23. Two attempts to blame global warming on volcanoes
    Tom Dayton: Remember that the difference between Solar Maximum and Solar Minimum TSI is near 1 W/m^2 .Taking into account the Spherical Surface of the Earth, this gives us a forcing of 0,25 W/m^2. Now 0,09/0,25 = 0,36 ... 36% of Solar Variability! If your data is true, it can be an important Climate Forcing on geological timescales!
  24. Two attempts to blame global warming on volcanoes
    To add to Tom Dayton's comment..although this is to do with CO2 emissions rather than heat from undersea/submarine volcanoes the US Geological survey has a comparison of CO2 emissions from volcanoes vs. human activities. ...Human activities release more than 130 times the amount of CO2 emitted by volcanoes--the equivalent of more than 8,000 additional volcanoes like Kilauea... http://volcanoes.usgs.gov/hazards/gas/index.php
  25. Two attempts to blame global warming on volcanoes
    Geothermal Heat emission = 0.09 watts/m^2 ? This is 10% of our measured Radiative energy imbalance of 0.9 watts/m^2! Where do you get this data? 10% seems too much!
  26. Two attempts to blame global warming on volcanoes
    Paz, the heat coming from undersea volcanoes along with the entire rest of the crust of the Earth (0.09 watts/m^2), is tiny compared to the forcing from CO2 (2.66 watts/m^2). For details, see my comments #234 and the following #235 in the Skeptic Argument Volcanoes emit more CO2 than humans.
  27. Two attempts to blame global warming on volcanoes
    This is a thing that continues to cause me a headache: The Early 20th Century(1900s-1940s) Warming of 0,4 ºC. It seems to me a lot strange that it peaked in the 1940s (then followed by a slight cooling of -0,1ºC until the 1970s) when both: a)Solar Activity peaked in the 1960s b)Big volcanos erupted(after near 50 years of calm) in the 1960s So, why Temperatures peaked in the 1940s and not in the 1960s? My suspect were Tropospheric, man-made AEROSOLS, but after seeing the GISS graph, TOTAL forcing still peaked in the 1950s at 0,5 W/m^2, still A DECADE(1950s) AFTER TEMPERATURES BEGAN TO COOL! What is going on? It could be: 1)Errors in temperature data or in the GISS total forcing estimation(this second is more likely as Aerosols Forcings are still considered "highly uncertain") 2)Climate Variability masking the (warming)forcing in the 1950s (for example, a series of weak El Niños and strong La Niñas) What do you think?
  28. Two attempts to blame global warming on volcanoes
    Is there any data on underwater volcano eruptions? An argument that seems to be popping up more and more is that global warming is driven by underwater volcanoes that (1) warm the oceans, which (2) in turn warm the athmosphere. Is there any data about whether this can be ruled out? I think the appeal of this argument comes from a) that underwater are supposedly hard to track (so a large scale increase of eruptions could be going on without our knowledge) b) several recent papers arguing that part of the recent warming is driven by the oceans. It did some searching and could not find anything on this hypothesis, although I am sure it must be out there.
  29. Why does CO2 lag temperature?
    oops I meant CO2 in this case not lagging temperature :$
  30. Two attempts to blame global warming on volcanoes
    Klaus, you may find this article helpful: http://climate.envsci.rutgers.edu/pdf/ROG2000.pdf On page 192 there's the following statement: "While the Mount St. Helens eruption of 1980 was very explosive, it did not inject much sulfur into the stratosphere." There's also a table on the same page comparing historic eruptions and the various indices used to measure the intensity of the eruptions and their effect on climate.
  31. Two attempts to blame global warming on volcanoes
    Klaus, the site urled just below has a list of all of the major known volcanic eruptions of the Holocene (having Volcanic Explosive Index of 4 and higher). If you click on each volcano in the list it gives you detiled information about known properties. You might get some info there as to why St Helens isn't on the graph. It was a pretty major explosion, but perhaps it didn't have a large effect on very high altitude transmission of solar radiation..??? http://www.volcano.si.edu/world/largeeruptions.cfm?sortorder=desc 70n, a very quick way of assessing the Mauna Loa record is to compare it with the record of CO2 averaged over the sea surface sites. The data are continuously updated at the NOAA Mauna Loa site. The Mauna Loa record is very similar to the record of the sea surface average: http://www.esrl.noaa.gov/gmd/ccgg/trends/
  32. Klaus Flemløse at 03:49 AM on 19 January 2010
    Two attempts to blame global warming on volcanoes
    I am very facinated by the Mount St. Helens explotions in 1980. To me it was big.However is not at the graphics. Is it as mistake ? Do you have a listing of vulcanoes by size ? http://en.wikipedia.org/wiki/Mount_St._Helens
  33. Two attempts to blame global warming on volcanoes
    Yeh? Well it's nice to have that off the list of arguments. All we have to do now is minutely scan every centimetre of the sea floor for volcanoes, (who are there in their millions apparently, pumping away in vast numbers with out changing the temperature profile or acidity of the ocean significantly, which is thoughtful) and you might even cause some ambivalence on this issue in a few heads.
  34. Two attempts to blame global warming on volcanoes
    Thanks, 70rn. It's even simpler to point at all the other CO2 monitoring stations that have been set up elsewhere: http://gaw.kishou.go.jp/wdcgg/ Just as an example, I clicked on "Data / Quick Plot", then "Barrow" (Alaska), then "CO2 (continuous)", then chose Monthly data "File / Quick Plot", and plotted the result as a PNG. Lo and behold, a nice rising trend in CO2 from 1973 onward, with a strong seasonal cycle, too. I don't know of any volcanoes at Point Barrow, and I am unaware of any volcanoes that belch CO2 with such a nice, smooth, consistently rising trend over three decades!
  35. Two attempts to blame global warming on volcanoes
    Here's a paper discussing the detection and removal of local co2 emissions from the Mauna Loa ('mount' obviously, but get better search results when you that term) record. Basically it states that localized co2 from the vents is at a completely different concentration and not mixed with the surrounding air and as such easy to distinguish from the background. It also notes that it is variable minute by minute - were as background data is steady over hours.
  36. Two attempts to blame global warming on volcanoes
    @ Ned Yeh the Mount Loa comment is pretty hard to shake off. A point to highlight to those that make this claim is the lack of a spike in the data last time it erupted (84) and the fact that the volcanoe has been overall less active than normal over the following quarter of a century, and as such if the readings were contaminated by the site then the data should have shown a corresponding decline. I don't doubt that the current data is calibrated against other sites in the NOAA network as well as secondary observations from sources like weather balloons.
  37. Two attempts to blame global warming on volcanoes
    Very well done, John. There are additional variants on this too, like the claim that submarine volcanoes in the Arctic Ocean are responsible for the decline in sea ice (you can see this from time to time on WUWT), or the claim that because the oldest CO2 measurement station is on the side of Mauna Loa, CO2 isn't actually increasing at all, it's just local contamination. Anyway, lacking your patience I usually see claims that "volcanoes are the real cause of AGW!" as evidence that the person making the claim doesn't have enough common sense to justify my participation in a serious discussion. But it's good to see that not everyone shares my impatience. This site is fantastic, and I've recently taken to directing people over here whenever I run across another version of the standard "un-skeptical skeptic" talking points.
  38. 2009 - 2nd hottest year on record while sun is coolest in a century
    Trog writes: "[...] I tend to trust [UAH] more than GISS since it is satellite data and not subject to as much manipulation. UAH shows a declining trend more in line with the sun." There are at least four satellite-derived temperature analyses (from RSS, UAH, and two from UW). Their current temperature trends are as follows (in K/decade): RSS: +0.15 UAH: +0.13 UW-RSS: +0.15 UW-UAH: +0.11 All four of these show positive trends during a time when the sun has been cooling. (They're also not all that far from the GISS trend, which is +0.16 K/decade over the same period) In other words, the relatively small effect of the solar cycle on global climate is only partially reducing the impact of CO2 driven warming. And of course once the sun starts to warm again, it will be exacerbating the problem (slightly) rather than helping mask it as it does now (slightly).
  39. Skeptical Science now an iPhone app
    Oopps. The graphs were not pasted. How can I post graphs, or any kind of figure? In the graphs, my numbers were: Total Forcing (1950s): 0,5 W/m^2 Solar Forcing (1950s): 0,2 W/m^2 Residual (1950s): 0,3 W/m^2 This is aerosol + Greenhouse gases + Land use change. The analysis forcing-by-forcing for tomorrow. Stay tuned.(please help with the graphics)
  40. Skeptical Science now an iPhone app
    Well, this is my previous comment, in graphical mode: First the Various Forcings from NASA GISS, showed the solar forcing: Then the TOTAL FORCINGS: So 0,3 W/m^2 were NOT from the Sun. They were from Aerosol + GHG. (note:all numbers approximated from reading the graph)
  41. Why does CO2 lag temperature?
    RE# 39 thingadonta I don't think it's a preoccupation at all, it is the strongest link as to why there is a temperature anomaly over the last 50 years. And to keep making sure of this, more and more measurements and analysis are performed to verify it.(And lets not forget methane) It's fantastic that scientists can recreate past climates and find the causes as to why there was sudden shifts in atmosphere composition or biodiversity to major geological events, Earth's precession or even meteorites. Examples like the closing of the Isthmus of Panama are on the millions of years (geological) time scale. On the much much shorter climate age time scale, things like the general circulation or the pattern of the ocean conveyor belt are relatively stable compared to the geological events you have mentioned. In the context of climate ages, with CO2 being very strongly infrared active, , the sudden recent spike in CO2 ppm in the atmosphere, the sudden recent spike in globally averaged temperatures, empirical data showing CO2's effect on radiative forcing, (and temperature in this case not lagging CO2)it is impossible to overlook the villain.
  42. 2009 - 2nd hottest year on record while sun is coolest in a century
    "...we've just established that the sun has been cooling over the last 35 years while global temperatures have been rising." Well, the radiometer measurements must have been manipulated. Or the sun must have been manipulated. Whatever. Will The Team stop at nothing in their quest to establish a global Marxist wealth redistribution machine?
  43. Skeptical Science now an iPhone app
    John Cook: Thank you (and Hansen, obviously) for the graph! To you and to readers: What forcing do you think(personally) could explain better the Early 20th Century (1910s-1040s) Warming? a)The Sun b)Aerosols (Black Carbon + Sulfate)
  44. 2009 - 2nd hottest year on record while sun is coolest in a century
    As Algore said, "It's complicated". UAH has a very different ranking of hottest years, which I tend to trust more than GISS since it is satellite data and not subject to as much manipulation. UAH shows a declining trend more in line with the sun. In any event, sun activity matches temperature better than CO2 concentration. Now, if you can model sun, humidity, high and low clouds, ice and snow, ocean currents, CO2, wobble, solar flares and cosmic rays all operating in a chaotic relationship with unknown interactions and lags, you might be making some progress. I don't think we're there yet. I'll stick with observations and not trust models for now.
    Response: That the UAH satellite data is pristine, untouched data seems to be a common misconception. On the contrary, satellite data is subject to a great deal of manipulation. Orbit decay causes the altitude of the satellite to drop so that needs to be filtered out. The temperature of the actual satellite also changes and this affects the readings. Data from different satellites need to be spliced together. Cooling in the stratosphere needs to be filtered from the warming in the troposphere. And probably the most complicated adjustment is accounting for diurnal drift - the time of the day that the satellite passes over the equator slowly drifts over time (exacerbated by orbital decay). In fact, diurnal drift is the greatest source of discrepancy between the UAH data and RSS data.

    And I must say, I find it extraordinary to hear you say "sun activity matches temperature better than CO2 concentration" when we've just established that the sun has been cooling over the last 35 years while global temperatures have been rising.
  45. Tree-rings diverge from temperature after 1960
    I'm guessing that acid rain had a *lot* to do with the sudden decline in tree-ring width post-1960. It certainly doesn't prove any kind of global cooling post 1950. It does, however, highlight the need to use more than a single proxy for determining climate in the absence of direct temperature measurements
  46. Skeptical Science now an iPhone app
    John Cook: In the comment to the previous post, I said: "The Early XX Century Warming(+0,5ºC) peaked at about the same time than WWII(around 1940), then a slight cooling of about -0,1ºC followed until about 10 years when temperatures stayed nearly constant between 1955 and 1975. The Sun Activity instead continued to incrase until mid-1950s, when it began a slow decline. Remarcable is that temperatures peaked BEFORE Solar Activity (a whole solar 11-year cycle indeed!). This seem inconsistent with the hypothesis that the Sun is the main responsible of the Early 20th Century warming." Then I talked about the Aerosol Forcing hypothesis(sulfates,black carbon...), and concluded with the question: "Has anyone compared the Sulfate vs. Black Carbon emissions making timeseries-graphs like the one presented here? (I referred to the TSI vs. GISS Temperatures in the previous post) That will do a good to determine which forcing (Solar or Aerosols) had the greatest impact." John Cook, I am still waiting for your response.
    Response: The estimated radiative forcing from sulfates and black carbon are available for download from the NASA GISS website. Please feel free to make a time series graph (and if you do, let us know what you find).

    Line plot of showing separate radiative forcings, 1880-2003
  47. Skeptical Science now an iPhone app
    This exercise has not been solved for many decades. I don't think is going to be solved any time soon even by solar physicists, let alone we readers :)
  48. Scientists can't even predict weather
    The wave/tide analogy is a good one. Both are cyclic. Long term climate is also cyclic, not linear. The formula to convert radiative flux (RF) to surface temperature change is (ΔTs): ΔTs = λRF, where λ is the climate sensitivity parameter. This assumes ALL GHG forcing factors are equivalent despite that clouds produce negative feedback. Models that use a linear equation can only produce linear predictions based on recent trends. Even IPCC scientists say that GCMSs should be exercised on weather. http://environmentalresearchweb.org/cws/article/opinion/35820 The global energy budget (Kiehl/Trenberth) features high in the computations but the net positive radiative forcing is derived from Hansen's computer model. "GH theory (IPCC: Myhre et al.) tells us that the CO2 climate forcing from this increase equals 5.35 times the ln(ratio) = 0.035 W/m^2 Even if we escalate this by a factor of 3.2 to account for net positive feedbacks, as estimated by the IPCC model simulations, we arrive at 0.112 W/m^2 How do K+T arrive at 0.9 W/m^2 or eight times this value?" See http://chriscolose.wordpress.com/2008/12/10/an-update-to-kiehl-and-trenberth-1997/#comment-1493
  49. Skeptical Science now an iPhone app
    Is there any connection between Solar Cycle LENGHT and Total Solar IRRADIANCE? If yes, what is the link between them?
    Response: When the sun is showing a long term warming trend, the solar cycle tends to get faster. Conversely, when the sun is cooling, the solar cycle slows. This is why the solar cycle 24 is taking so long to get started at the moment - because the sun is cooling at the moment. Why this is so, I leave as an exercise for the reader :-)
  50. Temp record is unreliable
    Gavin Schmidt has a brief response to the Smith & Coleman bizarre claims that the "real" temperature stations' data have been replaced by averages of unrepresentative stations' data, and that data have been destroyed. Gavin's response is to Leanan's comment #9 on 17 January 2010 in the comments on the RealClimate post 2009 Temperatures by Jim Hansen.

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