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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 110351 to 110400:

  1. How we know the sun isn't causing global warming
    I very much appreciate the chriscanaris/Ned exchanges. I wonder then if it's a matter of definitions, like with many other things. "The sun isn't causing global warming" means more "whatever the sun has been doing in the past few decades, global warming due to greenhouse gases has been there regardless" than (literally) "the sun is unable to cause global warming".
  2. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Ned @144, Just had a look at your numbers. FWIW, they look good to me, although I cannot vouch for the contribution to global SL from glacial melt--although the NSIDC numbers valid up until 2003 may be too low (e.g., Dyurgerov (2002) notes that contribution from glaciers exceeded 2 mm/yr after 2000). Either way, as you say, the heat required/involved is too small to significantly affect the 0-700 m OHC numbers, i.e., explain the slowdown in OHC over the period in question. I'm beginning to appreciate Dr. Trenberth's frustration ;)
  3. How we know the sun isn't causing global warming
    nigelj, your question is not naive! It is excellent and common. The answer is in the post Climate Time Lag.
  4. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Ned, Thanks for taking the time to respond to two questions I had posed. I do recall your prior posts. In this particular instance, I was just asking for some basic information about the amount of heat that has been "consumed" in the melting of the Greenland Ice sheet over a specified time period. I know that it pales in comparison to the amount of heat stored in the upper layer of the world's oceans.
  5. How we know the sun isn't causing global warming
    This is a good site and I feel the case for agw is very compelling, however I have one area of doubt regarding solar activity. Could the early 20th century largely solar forced warming be causing or contributing to the current warming by some delayed action or feedback? I cant see how it would and presume its been ruled out. Im not a scientist and it may be a naieve question. Id appreciate some clarification.
  6. A detailed look at climate sensitivity
    Eric (skeptic) - I think that averages can be used if they are understood and properly chosen. As an example, Trenberth has recalculated upwards IR from the Earth's surface in his energy budgets to be an average of 396 W/m^2, rather than the earlier value 390 W/m^2, due to a better understanding of surface temperature variations and the effect via the T^4 relationship of temperature and energy emitted. If the average is properly chosen, it will be fine as a model input, even if the gridding is much larger than the fine level detail of water vapor levels or cloud coverage.
  7. A detailed look at climate sensitivity
    Chris G (#35), you are mostly right that weather and other internal factors should have some paleo consistency. But not completely right because of biosphere changes, geological and other long term changes that affect weather. The bigger problem is that paleoclimate estimates require a mutual relationship with no other external factors. Unless there are paleo records of the other factors (partly possible) and a known relationship between those and the CO2 and temperature being estimated (not very well known). To take a simple example if some solar magnetic effect (e.g. GCM flux) affects both temperature and CO2, then the sensitivity of temperature to increased CO2 alone cannot be determined from those two proxy measurements.
  8. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Badgersouth writes: Has anyone computed the annual mass of Greenland ice cover loss/gain from 2000 through 2009? How many Joules of energy does it take to melt a cubic meter of ice? My guess is you're wondering whether the "flattening" of ocean heat content that Dr Pielke refers to is attributable to the latent heat associated with melting ice. It's a reasonable question. I tried to address it a couple of days ago, when somebody asked about it in another thread. Here's a link to my first comment, and here's a followup (with further details and correction of a typo in the first comment). The bottom line is that obviously heat that goes into melting ice means less heat raising the temperature of the ocean. But the amounts involved (for both declining Arctic sea ice and melting land ice) are about two orders of magnitude smaller than the OHC anomaly numbers. It's just too small to have much of an effect.
  9. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    @135 If I read correctly the discussion, melting ice is not enough to explain the lack of energy in the ocean. Or Argo is wrong or the satellites are. So what other indices show an increase in temperature since 2004? The existence of these show that there are problems with ARGO. Get it right?
  10. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    In discussing the point that 2004-2009 is too short a period to see such trends, it should be clarified more precisely *why* we might not expect to see changes over that length of time. There are in fact several reasons I can think of; others can perhaps think of more. (1) The rate of change in both ocean heat content and in surface temperature expected from global warming is still small enough that the change only emerges from statistical noise (inherent and/or measurement-related) over longer periods of time. (2) Over short periods of time there are processes within our climate system that introduce substantial variability which, over longer periods, average to zero. ENSO in particular has a major impact on 2-3 year variability. Also don't forget we've been near the bottom of a solar cycle for a few years too (so incoming solar is 0.2 W/m^2 or so less than the average right now just from that). (3) Plain old weather - cloudiness levels and storm systems can persist to some degree for a month at a time (like the Russian drought, Pakistan floods situation this summer). These have a major impact on Earth's energy balance over the short term, and while they average out over the period defining weather, the natural statistical variability they introduce into Earth's energy balance almost certainly overwhelm global warming signals (so far) over the few-year time frame. Agreed?
  11. A detailed look at climate sensitivity
    BP, thanks for the link, I agree completely. The use of averages in grid cells is not much different, philosophically, than using world wide parameterizations for water vapor feedback. It's a lot of use of ideal or heavily simplified relationships, which are valid in some cases by definition and then assumed to have a plus and minus delta on each side of them that averages out. KR, the cloud argument is valid and affects both IR back radiation and albedo. But the concentration of water vapor outside of clouds is just as important (if not more). Each point in space and time will have some thermodynamic formula for back radiation. Nothing much can be said about an average for an area (e.g. the size of a GCM grid cell or the whole earth) using global-average sensitivity formulas as suggested above. The main problem being that the formula cannot account for water vapor unevenness. Using climate models with volcanic aerosol inputs without being able to model the weather (e.g. mesoscale convection) will simply produce an overestimate of sensitivity. For example http://www.independent.co.uk/news/science/pinatubos-summer-washout-volcanoes-erupt-and-the-worlds-weather-changes-bill-burroughs-explains-the-link-between-forecasting-such-effects-and-global-warming-1554179.html shows that weather itself was a negative feedback for this particular volcano preceded by El Nino (not lower humidity on a global average basis from a globally averaged volcanic cooling).
  12. How we know the sun isn't causing global warming
    Thanks for the good post, there's just one question left, I hope, it's not silly. You wrote dF = 0.7 * d(TSI)/4 This is a very straightforward and easy to understand formula - the larger the change in solar irradiance, the larger the energy imbalance it causes, and thus the larger the radiative forcing. Studies have reconstructed TSI over the past 300 years. Are there long term studies about the factor 0.7? Can we be sure, the albedo is a constant over centuries? For example, a change in cloud cover of about 2% can cause the same forcing as a doubling of CO2.
  13. How we know the sun isn't causing global warming
    #33: "you must be able to accurately tell us where we are in the cycle of 'natural' solar forcing. Perhaps Muoncounter could attempt an answer this time. " Why? If you are questioning the content of this thread - that the observed warming is not due to the sun -- do so with specific objections. Or, as you suggest in the prior exchange, are you looking for a magic TSI number, so that you can claim that CO2 forcing is minimal? If so, that question is dealt with in specifics elsewhere. My comment here was about galactic cosmic ray flux, which was specifically a part of this post; I am happy to debate that subject in depth if you like.
  14. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    As I understand it, SLR tends to concentrated around the equator due to centrifigual forces and ocean currents. If that is the case, would the OHC stored in the upper layer of the oceans be unevenly distributed, i.e., more around the equator and less elsewhere?
  15. A detailed look at climate sensitivity
    Dana1981, Thanks for the excellent article. #3 Thingadonta, I think you raise some valid points in that the pattern of the change can be different between different sources of an imbalance. For instance, the pattern caused by an increase in solar output can be different from an increase in GHGs. There are articles on this site and elsewhere which identify these differences; for example, a larger rise in nighttime lows than in daytime highs is associated with a higher GHG content in the atmosphere where that would not be the pattern expected from an increase in solar output. However, the atmosphere and oceans do a pretty good job of distributing the energy over the globe, and in the long run, energy in is very close to energy out (radioactive decay and others making up the tiny fraction difference). #29 Lars, I think you'd have to propose a climate system where Antarctic and Greenland were isolated from the rest of the world for tens of thousands of years, in order to seriously question that there is a relationship between the ice core derived temperatures and the global average. It's pretty well known that the record is not a global proxy. However, they are, in part, based on oxygen isotope ratios. I'm willing to accept that oxygen is pretty well mixed in the biosphere over periods of thousands of years. Werecow, I'll second what CBDunkerson said, and add that an awareness that the sensitivity varies based on what is the current state can pretty readily be found in paleoclimate studies. On the distribution of water vapor and clouds: The really nice thing about the paleoclimate is that it takes all these considerations into account.
  16. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    I suspect that we have seen the last of Dr. Pielke and HumanityRules on this comment thread. Can anyone else answer the following two questions that I had posed to them yesterday. 1. Is the annual OHC to be computed by the NODC for 2010 likely to be higher, or lower, than the number computed for 2009? 2. Does Dr. Pielke postulate a theory about why global warming purportedly halted during the period 2004-2009?
  17. What caused early 20th Century warming?
    #37: "I was rather looking forward to your reply" Why? It seems as if you want to create some sort of straw man in the form of a quantitative branch for me to saw off. I had no idea that form of expertise was required in order to agree with a point raised in a 'basic version'. Your comment in 36: "small imbalance could mean Solar forcing only or a smaller CO2GHG effect that theoretically claimed" suggests that you would like someone to provide a number that will allow you to claim that CO2 effects are small; I'm not qualified to do that. However, the CO2 question is addressed in detail elsewhere. My observation in #28 still stands: a paper noted the long term cycle evident in the sunspot index. And I echo what kdkd said in #31: all this stuff can be estimated without estimating this 'equilibrium TSI'.
  18. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    A couple of points, ARGO measures heat content by measuring temperature and composition. The probes float at depth and surface every 10 days, during which they measure profiles. While the oceans have 90% of the heat content, it ain't 90% of the Earth's heat content, because that leaves out the mantle and the core. However, that is just the scientist in Eli, because the heat flow through the lithosphere is slow and small compared to that from the sun. The more serious point is that ARGO and the other probes do not measure the heat content of the deep ocean, but only of the upper 1km or so. That means they are NOT measuring the heat content of the entire ocean, something to keep in mind when looking at strong claims. So what can ARGO do?. It can measure the heat flow into and out of the upper 1 km layer of the ocean and that is very significant, but since it depends strongly on winds and currents, it is NOT a direct measure of global warming free of variation. It is a damped measure as can also be seen by looking at the time response to Pinatubo esp in the sea level rise
  19. A detailed look at climate sensitivity
    Berényi Péter @32 That is not a picture of water vapour
  20. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Badger @134/135, I'm not entirely sure where this line of questioning is going. I am not an expert on the "delayed oscillator" or exactly how ENSO may affect global OHC. Maybe someone else here can add some information. That said, I'm pretty sure that the "delayed oscillator" is now accepted widely in the community. As for the ice loss form Greenland, a new paper our in Nature (in which they used different correction factors, than those used in recent studies, to account for the impact of glacial isostatic rebound) suggests that the mean ice loss from Greenland between April 2002 and December 2008 was -104 (+/- 23) Gt/yr, and -64 (+/- 32 Gt/yr) from the WAIS. 1 Gt is about 1 km^3 of ice. As you can see, there are some issues closing the global SL "budget".
  21. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Badgersouth @135, see the link I just posted for ari. It has Greenland and Antarctic ice mass graphs for the period since 2002.
  22. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    ari @125, as has been mentioned, five or six years is too short a period of time to say anything definitive, but here is a site where you can see some of the key indicators and decide for yourself if the trends are continuing: http://climate.nasa.gov/keyIndicators/index.cfm Note that this year's arctic sea ice minimum looks like it will be somewhere in the vicinity of 2008's number. It is already considerably lower than 2009 by every measure I've seen. We'll likely know this year's number within a couple of weeks. (Also, it looks like their 2009 number is wrong -- not sure what the problem is, but it looks about a million km^2 too big, so maybe it's just a plotting error.)
  23. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Albatross: Has anyone computed the annual mass of Greenland ice cover loss/gain from 2000 through 2009? How many Joules of energy does it take to melt a cubic meter of ice?
  24. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Albatross @ 131 Is the science settled on the causes of the "delayed oscillator"? Does the "delayed osciallator"impact the amount of OHC stored in the upper layer of the ocean system that is measured by the ARGO system?
  25. Climate change: Water vapor makes for a wet argument
    Doh: I don't think it does.
  26. Climate change: Water vapor makes for a wet argument
    JohnD @79 OK, I think I understand your problem with the diagram. The figure of 324 backradiation comes from heat accumulated in the atmosphere over time. The figures of 168 and 324 imply to me that solar irradiation takes, on average, twice as long to leave the atmosphere as enter it. This is, of course, the essence of the greenhouse effect; heat is trapped for a period of time in the atmosphere, and the more greenhouse gases, the longer that period of time. I think you are trying to read the diagram as if it applied "from day 1" as it were; I don't it does. Make sense ?
  27. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Dr Pielke @115 You clarify that a snapshot is a month's average data. Can you please explain your rationale for choosing a one month period as indicative of the overall heat balance. It seems to me from a visual inspection that the noise overwhelms the signal for even a three month period, and that, as I posted earlier, several year's data might be needed. Presumably however, you've done a proper in depth analysis of the data to identify the time period necessary to differentiate signal from noise - it would be really interesting to share that please ?
  28. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    129. Rob Honeycutt states: "This is the big game and the fans are drunk on politics. Climate change is an issue that we need to get right. If you're passing out shots of bourbon to the fans you're doing a massive disservice to science." Especially true if the bourbon is being passed out a conference sponsored by the George Marshall Institute.
  29. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Badgersouth @130, Yes, as far as I understand the mechanism for El Nino is referred to as the delayed oscillator. The cause is most certainly not undersea volcanoes as Monckton suggests. Read more here: http://iri.columbia.edu/climate/ENSO/theory/index.html
  30. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Has the scientific community reached consensus on the causes of the El Nino and La Nina events?
  31. A detailed look at climate sensitivity
    Eric (skeptic) and BP - Absolutely correct and very relevant, the distribution of cloud cover affects temperature. The question, which I have not seen solidly answered, is whether and how the distribution of cloud cover changes with temperature, and if so does it act as a positive (rising cloud height) or negative (expanded cloud area) feedback. Stephen Schneider in his last TV appearance stated that a 2% increase in cloud cover would halve the CO2 induced temperature rise (negative feedback), while a 0.2km increase in cloud height would double it (positive feedback), and that our current measurements are not accurate enough to determine those changes. Hence the wide range of climate sensitivity due to cloud feedback.
  32. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Here is an example of my problem with jumping the gun to use ARGO data as a new proxy to define global warming. Suddenly you start finding articles like this spreading all across the internet. This one titled "Arrrrggggg…Argo Shows Global Cooling." Written by a Dr. Jay L Wile Full article here. "Thus, while carbon dioxide levels have risen, the globe has neither cooled nor warmed overall in the past 30 years. If you look at the temperature in the graph from 2003 on, however, you will see a clear trend – the troposphere has been cooling since 2003. This is mostly like in response to the fact that the late 1990s were abnormally warm. Now, of course, all global-warming alarmists know these data. In fact, they used to be published on NASA’s own website, but when too many people started pointing to NASA’s website as evidence that “global warming” is not happening, NASA quickly removed the data." The full article is rife with inaccuracies from someone who claims to have a PhD in Nuclear Chemistry. I tried to locate a way to contact Mr Wile but the comments are closed and he has no contact information on the blog that I could find. This is exactly my previous point about rowdy fans. When the rhetoric too quickly shifts to OHC is global warming then you feed the obfuscation machine. These people are not going to look at the details. They aren't going to question whether the ARGO data is robust yet. They only want a reason to believe there is some crazy conspiracy going on. This is the big game and the fans are drunk on politics. Climate change is an issue that we need to get right. If you're passing out shots of bourbon to the fans you're doing a massive disservice to science.
  33. Antarctica is too cold to lose ice
    You can see the mass balance for antarctica at the following link http://www.skepticalscience.com/Part-Three-Response-to-Goddard.html
  34. A detailed look at climate sensitivity
    #24 Eric (skeptic) at 20:09 PM on 9 September, 2010 proving that humidity has gone up on average means nothing. The distribution of water vapor is the only thing that causes or doesn't cause global warming. If water vapor is evenly distributed then there is global warming, if not, global cooling. There is a large natural range encompassing both cases and a lot in the middle. You are right. See this comment at another thread for example. This is how unevenly water is distributed in the atmosphere: With a simple Zero-dimensional climate model it is very easy to demonstrate the effect. The more uneven atmospheric water vapor distribution gets, the lower average surface temperature goes. For a realistic range of parameters, entropy production of the system also goes up as water vapor gets lumpy, even if heat distribution along the surface is extremely efficient (same surface temperature everywhere). The main problem with analytic computational climate models is that they are unable to resolve these fine structures so they simply apply averages at sub-grid scales. To put it in another way you can see through a barbed wire fence easily. But if you take the average density of iron per unit area, it gets indistinguishable from a thin but absolutely opaque iron plate.
  35. Climate change: Water vapor makes for a wet argument
    Johnd - the backradiation from the atmosphere is driven entirely by the temperature (and humidity, to provide water vapor levels) of said atmosphere. Your table of data implicitly includes the backradiation, as anyone familiar with the subject understands that warm humid air keeps the ground warm, while cool dry air speeds temperature drops. That's basic knowledge in agriculture! You're asking for duplicate data. Scaddenp - The various soil temperatures are important for agriculture and crop growth; the purpose of these "Agricultural Observations" tables. Johnd - Trying to claim that backradiation isn't important simply because it's not listed on a table created for another purpose entirely is a very poor argument.
  36. How we know the sun isn't causing global warming
    This was last my post for Muoncounter (unanswered)from "What caused early 20th century warming", which is directly relevant to this discussion: "In the absence of any anthropognic forcings prior to 1750AD, the only climate driver would be the various Solar cycles including the 11 year cycle, and multiple overlapping orbital cycles which have varied the Earth's exposure to the sun. Volcanic cooling is transient and significant in short bursts, but being randomly distributed in time cannot be counted as part of a natural forcing cycle. The Earth is most probably never in equilibrium, but if you are trying to separate and quantify the effects of CO2GHG forcing - you must be able to accurately tell us where we are in the cycle of 'natural' solar forcing." In new words: "What value of TSI gives the Earth neutral (neither warming or cooling) Solar forcing?" Perhaps Muoncounter could attempt an answer this time.
  37. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    DW #104 I am glad that you cited that paper. It is good that my own independent (if not multiple) line of sclerotic engineer thought agrees with such a distinguished list of authors. Even kdkd is tossing bouquets in my direction.
  38. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    @ari no one can say yes or no, it's a too short period of time. Given that in a longer time span there has been warming and that the last about 6 years from 2004 are well inside natural variability and uncertainties (and apart from other reasons i'll not mention), we can only say that statistically we have no reason to believe that the trend has changed. I know, it's not a satisfactory answer, we'd like to have a "yes" or "no". But hey, this is how science works ;)
  39. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Looking at Dr Pielke Sr's responses here and elsewhere, it appears to me that his views on global warming are determined more by his political outlook than by any evidence-based science. How can you look at some of his assertions and not see the cherry-picking to suit whatever point he is trying to make at any particular moment ? For example : "Their has been no statistically significant warming of the upper ocean since 2003." Can one really determine any statistical significance using a 6-year period ? ...global warming [which, of course, has not occurred since at least mid-2004!]. He wrote this in 2008. Does Dr Pielke Sr still agree with this ? If so, on what does he base his assertion ? ...lower troposphere from, say, 2001 to the present, if anything it is slightly falling Why choose 2001 ? What does he think of the trend up to the most recent figures ? ...since about 1995, if you put a linear plot since then, there has basically been no further cooling of the stratosphere Again, why choose 1995 ? Why not choose 2001, which was chosen for the lower troposphere ? Again, what does he think of the trend up to the most recent figures ? ...arctic ice level so it is higher than it was this time last year, How can anyone assert this as if it meant anything serious, especially a scientist ? What is it supposed to mean ? Again, what does he think of the most recent figures compared to this time last year ? ...Antarctica, for the last number of years, actually has been increasing in its sea ice coverage. How many years is 'the last number of years' ? What does he believe this means ? ...the climate hasn’t been warming over the last number of years. Again, How many years is 'the last number of years' ? Is it 'since at least mid-2004', as he asserted above ? Does he still agree with that assertion ? There is also this from an interview he gave last year : the globally averaged lower atmosphere has not warmed in the last nine years (and, in fact, is cooler than it was in 1998). How does this assertion (using a start date of 2000, presumably) tie-in with the previous claim of 'since at least mid-2004' assertion, which he wrote the previous year ? Is this what he meant by 'the last number of years' ? And why highlight the record temperature year of 1998 ? Does he think that 2010 will continue to prove his assertion that there has been no warming 'in the last nine years' ? Generally, I am always disappointed when I find scientists cherry-picking and letting their personal politics determine their assertions. In fact, Dr Pielke Sr's determination to continue along this line was confirmed by his recommendation of a book by his son. No surprise that a father would recommend his son : it was the title of that book that spoke volumes to me, and highlighted what I think is the rationale behind the views of certain people. The title of that book is 'The Climate Fix: What Scientists and Politicians Won't Tell You About Global Warming'. That encapsulates neatly what so-called skeptics believe, whether they are involved with the science or just believers of a certain viewpoint : AGW is a 'fix' (or conspiracy), being used by politicians to do whatever they want to do - usually restrict our freedoms, put up everyone's taxes and enrich themselves, of course. Especially Liberal or slightly-left-of-extreme-right politicians. And by associating scientists and politicians together, they can proclaim that scientists are in on the 'fix', doing it for the politicians, and enriching themselves or controlling us all by producing results that have already been agreed in advance by some secret cabal. It would all be very funny if it wasn't so sad and serious. Dr Pielke Sr, you won't care what I think of you but I am disappointed that there are scientists like you who are prepared to interpret and provide partial results in ways that give your audience what they want to hear, and which, purely and simply, conform to your political viewpoint.
  40. Using Skeptical Science to improve climate literacy
    Thanks for this note, Lee. It's great that you were able to use this site as a resource in the workshop.
  41. The Little Ice Age: Skeptics skating on thin ice
    thingadonta writes: LIA and low solar activity shows a good correlation, meaning small changes in solar output are magnified, ie positive feedback, possibly by clouds. If there are strong net positive feedbacks in the climate system, that means that climate sensitivity must lie on the high end of the range and 21st century warming will probably be worse than models predict. Is this really an argument you want to make? thingadonta continues: At least 2 provable lag effects with regards to solar activity are known -daytime maximum T after highest solar output (around 25% lag time), and seasonal maximum T (again, around 25% after maxmum solar output). Applying 25% lag time to the solar output from 1700-1950 indicates maximum T around 2010-now. Oh, come on; there's no physical basis for a constant "25% lag time" that can be consistently extrapolated across temporal scales from a single day to multiple centuries. But in any case, once again this would be bad news for the 21st century since it would mean that more of the impact from our previous CO2 emissions must still be "in the pipeline". thingadonta continues: Its interesting that you call the causes of LIA- a known event- as speculation, but something that hasnt even happened yet, projected T rises, this site calls their likely causes as solid as a rock! Why is that surprising? We can only study the LIA through sparse historical records, uncertain proxies, and climate models. We can't go back in time and place satellites in orbit to measure TSI, volcanic aerosols, etc. In contrast, we know much more about the current climate. We know that TSI is stable or slightly declining, we know that CO2 is increasing and that it's coming from fossil fuels rather than the oceans, and so forth. This is not to be dismissive of paleoclimate studies -- we really can learn a lot about the MWP, LIA, etc. from historical data, proxies, and models. But it shouldn't be at all surprising that we know much more about what's happening today.
  42. Using Skeptical Science to improve climate literacy
    Just wanted to say thanks to the contributors on this site. I have followed a, perhaps misguided, mission to get on conservative web sites and use their comments section to try and correct the many false ideas out there. I am sure I have not changed many minds but this site has been invaluable in helping me counter ignorance with information.
  43. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    My first post, I live in Brazil. I am totally a layman and would like to ask the following: It seems that several doubt the accuracy of the Argo data. So what other indices show that the warming continues from 2004?
  44. How we know the sun isn't causing global warming
    I'm no expert but I thought that Dansgaard-Oeschger events didn't make the whole globe hotter, they made the hemispheres go in opposite directions, one hotter, one cooler. And I didn't think it was so well established that the timing is always so regular; I thought that there was still substantial disagreement about it (from sensible people, not the wingnuts).
  45. Philippe Chantreau at 18:34 PM on 10 September 2010
    The Little Ice Age: Skeptics skating on thin ice
    Thingadonta at #13: we already discussed the diurnal temperature changes before and clarified that there was no "lag" so you should at least leave the diurnal cycle out of your speculations. A couple of months ago, Arkadiusz was kind enough to point out the SHALDRIL project. Milliken has studied the core extensively and says: " There is no compelling evidence for a Little Ice Age readvance in Maxwell Bay. The current warming and associated glacial response in the northern Antarctic Peninsula appears to be unprecedented in its synchroneity and widespread impact." http://gsabulletin.gsapubs.org/content/121/11-12/1711.abstract
  46. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    What? Climate is weather averaged over 5 years? Has WMO changed the definition? n/t
  47. Climate change: Water vapor makes for a wet argument
    johnd - well ask them but they take measurements for a purpose and I suspect backradiation isnt that important for investigation CHANGES in evaporation on land. I do not think that seawater is like evaporation pans. What do you think would the liquid temperatures would be like at night in seawater compared to a pan? I would also guess that on land most evaporation happens in day time with little at night. Evaporation continues at night over sea because surface sea temperature dont fall much. By "Ground" temperature, I meant surface temperature. No backradiation and temperatures would plummet at night. The direct solar is stronger while its shining but backradiation continues at night. You seem to disbelieve backradiation because BOM doesnt it at their evaporation pan sites. How do you account for the measurements at the 1600 sites where it is measured then?
  48. Climate change: Water vapor makes for a wet argument
    scaddenp at 14:07 PM, why wouldn't they measure radiation from the atmosphere, that seems strange. Given it is supposed to be twice the magnitude of direct solar radiation it would then be the single largest input into the process. It doesn't make sense that you now claim that back radiation is manifest in the ground temperature. Ground temperature is very stable, it varies only slowly, especially if any moisture is present as the evaporation of moisture actually is a cooling process removing heat from the surface, and as can be seen, other factors have far greater influence in varying the rate. Ground temperatures do respond more rapidly once surface moisture has been removed through evaporation. These measurements are not strange or far removed from the conditions at sea. The actual measurement of evaporation is taken from water in a standard evaporation pan, the same as what would be used to measure evaporation rates in a marine environment.
  49. The Little Ice Age: Skeptics skating on thin ice
    Surely the "recovery from the LIA" argument fails on basic logic anyway? It's much warmer now than it was before the LIA, by that logic temperatures should have levelled off before now. It's like saying you are still climbing out of the valley when you are half way up the mountain.
  50. Pielke Sr and scientific equivocation: don't beat around the bush, Roger
    Albatross, I agree with everything you said. Except in my case it will be ice cream, not popcorn. I'll let those of you on the other side of the planet pick up the baton for a while. Good night.

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