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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 127451 to 127500:

  1. How we know global warming is still happening
    Oh well Robbo, in order to make your point you have to tell porky pies. Two lies now. First you took a paper whose observations and analyses are completely at odds with your non-scientific position...and inserted a phrase into the abstract to pretend that the paper agreed with your false analysis. And now you say that: "The addition '1976 to 1998' is relevant and placed in brackets to indicate that I added it." But that's obviously not true as inspection of your post #3 clearly shows. You put the entire (nearly) two sentences in brackets two signify that the section was a direct quotation (which it almost is as can be seen from my reproduction of what Trenberth and Fasullo actually wrote). You didn't place your sneaky and false addition in a seperate bracket to indicate that you added it, at all. Surely if you have to tell porkies to attempt to shore up a position, there is something seriously wrong with your point of view...at the very least it's not a scientific one. Just to be very clear the paper that you have attempted to misrepresent (Trenberth and Fasullo) analyzes models to determine the attribution of warming from 1950 through to the end of the 21st century. They find, in complete contradition to your false assertion, that during the period 1976 to 1998, the absorbed solar radiation (ASR) has decreased, and thus this has ofset some of the anthropogenic greenhouse-induced warming. This is largely the result of enhanced aerosolic screening. This situation is expect to persist up to around 2020-2040 after which absorbed surface radiation will increasingly dominate accumulating surface warming in greenhouse-enhanced world. Note that the published evidence indicates that the oceans are continuing to take up heat as expected in a warming world [see papers cited in the top article and also the von Schuckmann et a (2009)] paper in my post #5. Note also that you've misunderstood Swanson and Tsonis and Keenleyside, both of whom are pretty mainstream with respect to scientific understanding of the earth's response to enhanced athropoenic greenhouse forcing. The world is going to get a whole lot warmer in both of their analyses. To be specific: Keenlyside et al. [*] These authors use a model that incorporates analysis of sea surface temperatures and estimates of ocean current effects to make hindcasts and forecasts. They project (see their hindcast/forecast in their Figure 4) that a rather marked surface warming of around 0.5 oC in the period 2010 and 2025. Swanson and Tsonis [**] It's worth looking at the most recent paper on his subject by these authors. They analyze 20th century surface warming and attributons to "tease out2 anthropogenic greenhouse forcing contributions and natural variation. The conclude that the anthropogenic forcing has been (and continues to be a monotonic, accelerating warming during the 20th century). This has been modulated by natural contributions, especially ocean current effects on surface temperature, the net contribution of which to 20th century warming has been close to zero. These authors remark on the possibility that natural variation might result in a suppression of surface warming for a period. However they also point out that "However, global warming could likewise suddenly and without any ostensive cause accelerate due to internal variability.". None of this contradicts our understanding of the earths temperature response to enhanced greenhouse forcing, although recent analyss does reinforce the expectation that the time progression of warming is modulated by natural fluctuations. [*] N. S. Keenlyside et al. (2008) Advancing decadal-scale climate prediction in the North Atlantic sector Nature 453, 84-88 http://www.nature.com/nature/journal/v453/n7191/abs/nature06921.html [**]K. L. Swanson, G. Sugihara, and A. A. Tsonis (2009)Long-term natural variability and 20th century climate change. Proc. Natl. Acad. Sci. USA (in press) http://www.pnas.org/content/early/2009/09/09/0908699106.abstract
  2. There is no consensus
    Chris. Regarding your point 1 above "1. It's not possible to reproduce the temperature evolution using known climate contributors without incorporating anthropogenic greenhouse forcing." As I understand it, the authors of chapter 1 of "Climate Change 2001 - The Climate System : An overview" wrote : " The fact that global temperature has increased since the late 19th century and that other trends have been observed does not necessarily mean that an anthropogenic effect on climate has been identified. Climate has always varied on all time scales, so the observed change may be natural".
  3. There is no consensus
    Any graph can be made to emphasise what the maker of the graph wants to show. The IPCC is particularly good at this, even going as far as shading in the green ( good ) bits and the red ( bad ) bits on some of their graphs. The graph example I gave simply shows the data from a different perspective. I assume you have no problem with the actual data plotted on the graph, only the way it is presented? In terms of what the graph is designed to show, it is correct. If it does not clearly show the IPCC's "catastrophic" temperature increases of 0.5 degrees or so, that is because the graph is not designed to show that. There are many other graphs which show that. Anyone interested in AGW will no doubt look at many graphs and hopefully he/she will understand what is shown on each graph and understand how it has been presented. Why did you send me information regarding how graphs should be presented in a scientific journal. When the graph I mentioned was never made to be presented in a scientific journal.
  4. How we know global warming is still happening
    The addition '1976 to 1998' is relevant and placed in brackets to indicate that I added it - I obviously have to spell everything out or take the risk of silly and irrelevant comment. This is the only period of surface warming in the last 50 years - and the warming was associated with decreasing cloud from 1984 to 1998 as shown in the ISCCP records - about 3.7W/m2 increase of shortwave radiation from 1984. The surface temperature record shows cooling to 1975, warming to 1998 and cooling since. This is apparent in the monthly anomalies in any of the records. So we have had 22 years of net warming in the 50 year record. It is simply a fact of life. The IPCC is explicit is attributing most of the warming in the last 50 years to anthropogenic influences - and very little to natural variability. There is no strong heating or cooling in the ARGO record. These records are subject to endless revision despite which the evidence for heating and cooling is still not definitive. To claim that the evidence shows continued warming is nonsense. The conclusion is inescapable - there is no evidence of continuing ocean warming (or cooling) within the limits of error. However, there is an expectation of ocean heating and cooling in line with the scientific evidence for cyclic ocean states. You guys can continue to deny cyclic ocean states for as long as you like - it takes strength of character or an extreme foolishness not susceptible to evidence. Anything that shows complexity and uncertainty and challenges Chris' simplistic understanding is confidently labelled cheery picking. Some warming, of the oceans in particular, from 1975 to 1998, comes from changes in clouds. Amy Clements et al describe this as a positive global warming feedback. It has turned around however and is consistent with established patterns of multidecadal ocean cyclic states. Multiple lines of evidence rather than a stubborn refusal to accept evidence of anything that suggests a lower climate sensitivity to greenhouse gases. I am not skeptical at all - the question is how much warming was due to AGG and how much is natural variability. The only sensible way of approaching this problem is to consider net warming over a full cycle of 20 to 30 year warming and 20 to 30 year cooling. For the 1945 to 1998 period - this is a net warming trend of 0.08 degrees C/decade from all other factors - less than half of what is assumed by the IPCC. 20 to 30 years of an ocean warming record is not sufficient to disentangle natural cyclic variation on multidecadal timeframes from AGW. This is simply a scientific and statistical truth. Pointing to ocean warming in a rising phase and insisting that this proves something is nonsense. The lack of recent strong ocean warming is not consistent with climate forcing as determined by the IPCC. Surface warming has not been 0.2 degrees C/decade over the last decade as predicted by the IPCC - you can rabbit on about natural variability without being specific at all - and project vastly increased warming in future decades - or you can look for the causes of natural variability operating now and in the recent past and consider rationally the implications for AGW theory. This is why the lack of recent ocean and atmospheric warming falsifies IPCC theory – it is simply not consistent with the Earth energy budget with the theorised forcing – it is a problem that requires reanalysis of the forcing rather than pillorying of anyone who has the temerity to suggest that the emperor’s clothes are in tatters. It is entirely reasonable to expect – as with Swanson and Tsonis, Keenlyside etc – a lack of global ocean or atmospheric warming for 20 to 30 years from 2000.
  5. How we know global warming is still happening
    As well as the growing number of recent papers that demonstrate a continuing uptake of heat into the worlds oceans, the following paper has just been published: K. von Schuckmann F. Gaillard and P.-Y. Le Traon (2009) Global hydrographic variability patterns during 2003–2008 J. Geophys. Res. 114, C09007, doi:10.1029/2008JC005237 abstract below [***] This analysis indicates that if ocean heat content to a depth of 2000 m is assessed, that there has been a rather larger continued uptake of heat into the oceans (compared to, for example, the Levitus data that analyzes heat in the upper 700 m of the oceans; see Levitus data here) [***]abstract: Monthly gridded global temperature and salinity fields from the near-surface layer down to 2000 m depth based on Argo measurements are used to analyze large scale variability patterns on annual to interannual time scales during the years 2003–2008. Previous estimates of global hydrographic fluctuations have been derived using different data sets, partly on the basis of scarce sampling. The substantial advantage of this study includes a detailed summary of global variability patterns based on a single and more uniform database. In the upper 400 m, regions of strong seasonal salinity changes differ from regions of strong seasonal temperature changes, and large amplitudes of seasonal salinity are observed in the upper tropical and subpolar global ocean. Strong interannual and decadal changes superimpose long-term changes at northern midlatitudes. In the subtropical and tropical basin, interannual fluctuations dominate the upper 500 m depth. At southern midlatitudes, hydrographic changes occur on interannual and decadal time scales, while long-term changes are predominantly observed in the salinity field. Global mean heat content and steric height changes are clearly associated with a positive trend during the 6 years of measurements. The global 6 year trend of steric height deduced from in situ measurements explains 40% of the satellite-derived quantities. The global freshwater content does not show a significant trend and is dominated by interannual variability.
  6. There is no consensus
    re #159 Goodness Neil, that really is junk! I assume that the graph at the bottom left of the page that you refer to is to illustrate how one can "magic" the disappearance of real changes in observables, and thus remove essentially all information from the reader! The data in a graph should pretty much fill the space available. After all the point of presenting a graph is to inform the reader, and (I'm sure you know this as someone who has written and reviewed technical papers) this is best done by allowing the data to fill the graph (i.e. don't show unnecesary empty space by having axes that extend way beyond the actual data). In fact as I'm sure you know, this is standard practice in presenting scientific data. I've reproduced a paragraph on data presentation from the "Instructions to Authors" of a scientific journal below (The Biochemical Journal as it happens, 'though one could choose many examples) which emphasises this very obvious point [***] The other point of course, is that a graph is never the only bit of information a reader will see, and there will always be some context. So for example a presentation of 20th century temperature evolution and atmospheric CO2 rise might be accompanied by the following relevant information: 1. It's not possible to reproduce the temperature evolution using known climate contributors without incorporating anthropogenic greenhouse forcing. 2. The temperature rise observed during the last 100 or so years is aproaching around 1/6th of the total temperature rise during the 5000 years of the last glacial to interglacial transition. 3. The very large rise in atmospheric CO2 since the pre-industrial age (around 115 ppm) is already larger than the CO2 rise during the entire 5000 years of the last glacial to interglacial transition, and has taken atmospheric CO2 levels to a concentration not reached during the last million years at least. 4. Current understanding of the relationship between earth surface temperature and greenhouse gas concentrations indicates that doubling of atmosphere CO2 results in an equlibrium temperature rise of the order of 3 oC. 5. The equilibrium temperature rise expected from levels of atmospheric CO2 that will be reached by mid 20th century, are similar to those exisiting during the last interglacial period when sea levels were around 4 metres higher than now... etc. etc. [***] from the "Instructions to Authors" (my highlights):
    Figures will usually be reduced in size to occupy a single column (width 8.5 cm) or less unless a larger format is necessary for clarity. All lettering and symbols should be produced to be at least 1.5 mm, but not more than 3 mm, after reduction. All curves and lines should be drawn clearly, and of a line thickness that allows for the reduction in size on final printing. Axes should not extend appreciably beyond the curves, and it is often unnecessary for an axis scale to start at 0; only the part of the scale relevant to the curves should be given.
    pretty standard stuff..
  7. How we know global warming is still happening
    re #3 Oh dear Robbo…that’s a horribly cherrypicked selection. Let’s have at one of your assertions “Trenberth and Fasula” (sic). Let’s compare what they said with what you said they said: Here’s what Trenberth and Fasullo said[***]:
    Global climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) are examined for the top-of-atmosphere radiation changes as carbon dioxide and other greenhouse gases build up from 1950 to 2100. There is an increase in net radiation absorbed, but not in ways commonly assumed. While there is a large increase in the greenhouse effect from increasing greenhouse gases and water vapor (as a feedback), this is offset to a large degree by a decreasing greenhouse effect from reducing cloud cover and increasing radiative emissions from higher temperatures. Instead the main warming from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.
    Here’s what Robbo pretended they said:
    I refer also to Trenberth and Fasula who suggest that the ‘main warming between 1976 and 1998 from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.'
    For some reason you’ve added the tiny phrase "between 1976 and 1998" to their abstract…..??? In fact Trenberth and Fasullo are commenting on the results of global climate models and their observations highlighted in their abstract relate to late 21st century effects. In fact (according to Trenberth and Fasullo) the absorbed solar radiation (ASR) has decreased through the middle to late 20th century (due to aerosolic effects amongst other things including clouds) and this has countered the enhanced greenhouse-induced warming to date. It’s expected to continue to do so through to about 2040 after which there is a marked increase in ASR that drives rather significant further warming through to 2100 [***] K. E. Trenberth and J. T. Fasullo (2009) Global warming due to increasing absorbed solar radiation Geophys. Res. Lett, 36, L07706 (abstract in blockquote above)
  8. How we know global warming is still happening
    How We Know that the Planet isn't Warming Your first egregious error - as shown by Harrison and Carson – is that 20 to 30 years of increase in ocean heat content is not sufficient to determine longer term trends in systems with inherent multidecadal variability - such as has been shown repeatedly and consistently in ocean/atmospheric interactions. ‘Is the World Ocean Warming? Upper-Ocean Temperature Trends: 1950–2000 D. E. HARRISON NOAA/Pacific Marine Environmental Laboratory, and Joint Institute for the Study of the Atmosphere and Ocean, and School of Oceanography, University of Washington, Seattle, Washington MARK CARSON Joint Institute for the Study of the Atmosphere and Ocean, and School of Oceanography, University of Washington, Seattle, Washington JOURNAL OF PHYSICAL OCEANOGRAPHY (Manuscript received 25 July 2005, in final form 10 January 2006) ABSTRACT Subsurface temperature trends in the better-sampled parts of the World Ocean are reported. Where there are sufficient observations for this analysis, there is large spatial variability of 51-yr trends in the upper ocean, with some regions showing cooling in excess of 3°C, and others warming of similar magnitude. Some 95% of the ocean area analyzed has both cooled and warmed over 20-yr subsets of this period. There is much space and time variability of 20-yr running trend estimates, indicating that trends over a decade or two may not be representative of longer-term trends. Results are based on sorting individual observations in World Ocean Database 2001 into 1° _ 1° and 2° _ 2° bins. Only bins with at least five observations per decade for four of the five decades since 1950 are used. Much of the World Ocean cannot be examined from this perspective. The 51-yr trends significant at the 90% level are given particular attention. Results are presented for depths of 100, 300, and 500 m. The patterns of the 90% significant trends are spatially coherent on scales resolved by the bin size. The vertical structure of the trends is coherent in some regions, but changes sign between the analysis depths in a number of others. It is suggested that additional attention should be given to uncertainty estimates for basin average and World Ocean average thermal trends.’ The second error is in opportunistic evaluation of recent ocean heat content. Warming or cooling since 2003 in any of the studies mentioned is not significant. It is like saying that 2005 in the annual GISSTEMP record warmer than 1998 when the 2 results are well within error bounds. Scientific nonsense in other words – intended only to mislead and deceive an unsuspecting and naïve public. Physical oceanic evidence suggests cyclic warming and cooling and this has been linked to Hale periodicity in solar output. Please note especially the comment on amplification of weak solar signals. As an example – Solar Physics (2004) 224: 455–463 C _ Springer 2005 HALE CYCLICITY OF SOLAR ACTIVITY AND ITS RELATION TO CLIMATE VARIABILITY O. M. RASPOPOV1, V. A. DERGACHEV2 and T. KOLSTRO¨M3 Abstract The periodicity of climatic processes along the Russian Arctic Ocean coast has been studied by analyzing the tree-ring chronologies for the regions close to the northern timberline. The wavelet analysis of annual series of conifer tree rings for the period 1458–1975 has revealed climatic oscillations with periods of 20–25 years. The amplitudes and periods of climatic oscillations in the region of Russian Arctic Ocean proved to exhibit appreciable changes. Especially strong climatic variations in comparison with the recent ones were found to occur during the Maunder minimum epoch when the period of oscillations increased from 22–23 years to 24–29 years, and oscillations with periods of 15 years appeared. After the Maunder minimum, the periods of oscillations and their amplitudes again decreased, and the 15–16-year maximum disappeared. Analysis of solar activity based on of radiocarbon (14C) concentration in annual tree rings has revealed a similar pattern in changes of periodicity before, during, and after the Maunder minimum. This suggests that quasi-bidecadal climatic oscillations and variations in solar activity can be connected with each other. A possible solar forcing of periodic climatic processes and its nonlinear influence on the atmosphere-ocean-continental system are discussed. The intense quasi-bidecadal climatic oscillations can be, in all probability, interpreted as resulting from amplification of a weak solar signal in the atmosphere-ocean system that has its own noises whose frequencies are close to the 22–23-year solar cycles. It would be astonishing on other lines of evidence if the oceans were warming at all strongly. Observations (see Project Earthshine) show an increase in Earth albedo since 1999 of about 1% - or 2 W/m2. This followed a decline in albedo from 1984 to 1998 - equivalent to additional shortwave forcing of 3.7W/m2. It has been suggested that the amplification mechanism involves clouds – either as amplification of small changes in solar irradiance or in response to variation in atmosphere ionisation by cosmic rays. I refer also to Trenberth and Fasula who suggest that the ‘main warming between 1976 and 1998 from an energy budget standpoint comes from increases in absorbed solar radiation that stem directly from the decreasing cloud amounts. These findings underscore the need to ascertain the credibility of the model changes, especially insofar as changes in clouds are concerned.' How do we know that the planet isn't currently warming? Because neither the atmosphere or oceans are currently warming at all - a result that is utterly inconsistent with IPCC reporting regardless of the time period.
    Response: So 30 years of warming oceans is not sufficient to establish a warming trend and yet alleged ocean cooling (which is doubtful considering all the evidence) over the last few years is sufficient to disprove IPCC reporting?
  9. How we know global warming is still happening
    Manuel, Are you implying the AGW warming is insignificant compared to the sun? When was the last time the sun managed to heat the earth at a rate of 0.9W/m2?
  10. Measuring Earth's energy imbalance
    Steve, "We're not talking about a field with competitors legitimately claiming greater certainty" Are you sure? I am not.
  11. Models are unreliable
    The real data up to 2008 shows that global temperatures are tracking below Hansen's (1988) scenario C since about 2005. As I understand the predictions of Hansen's models, scenario C relates to a drastic REDUCTION in the increase of CO2 growth. Yet in reality CO2 emissions have continued to INCREASE. So real temperatures are tracking even lower then Hansen's most optimistic prediction based on a drastic reduction in CO2 emissions. If I compare real data to Hansen's scenario B (assumed to represent CO2 emissions frozen at 1988 levels ), the real data is now about 0.4 degrees below that predicted by Hansen. This may not seem a lot, but these are the sort of anomlalies which the IPCC is describing as catastrophic. I would argue that Hansen’s model is not validated by real-world data and I think that as time passes, it is likely that Hansen's 1988 predictions will diverge even further from real world temperatures. Arguably, real temperatures should be compared to Hansen's scenario A ( continued growth in CO2 emissions ). If such a comparison is made, Hansen's prediction is about 0.6 degrees above reality.
  12. Measuring Earth's energy imbalance
    My point is that (a) the value of information provided is relative to what else is available (you'd lose clients because others in your field could provide more certainty in their estimates, but we're not talking about a field with competitors legitimately claiming greater certainty); and (b) they have a very good idea what the anthropogenic radiative forcing is -- it is positive and nowhere near zero.
  13. How we know global warming is still happening
    John, Great post. It really puts us humans in perspective, does it? If .9 W/m2 translates into 190,000 GW power plants, the more than 340 W/m2 of total solar irrandiance is a pretty big number.
    Response: Don't fall into the "sun big, me small" trap. As far as the sun and climate is concerned, it's solar variations that make a change to our climate. If the sun is shining away at a steady 340W/m2 without changing and the climate was in equilibrium, then the Earth's global temperature wouldn't change - the energy coming in from the sun would equal the energy radiating back out and the planet would be in energy balance. However, if solar activity changes (eg - the sun gets hotter), then the energy coming in is greater than the energy out. The planet is in energy imbalance and starts accumulating heat. As it gets hotter, the energy it radiates back into space increases until it's back in equilibrium.

    The amount that solar activity changes is relatively small. The amplitude of the solar cycle is about 1 W/m2. This translates to a radiative forcing of about 0.25 W/m2 and is estimated to have an effect of around 0.1C on global temperatures over the 11 year cycle. Similarly, the long term changes in solar activity are relatively small - upper limits of radiative forcing from the Maunder Minimum until now place it at around 0.23 W/m2.
  14. Measuring Earth's energy imbalance
    Steve, Examples and analogies usually cause problems, as already mentioned in this thread. Anyway. My point is that if I were to tell my clients that I really have no idea of what is the market value of their companies, I would lose them.
  15. Measuring Earth's energy imbalance
    Chris, Thank you very much for your highly detailed answers. Unfortunately, I am unable to access most of the papers you cite. "It turns out that this net radiation does have a generally linear relationship with the change in the earth's surface temperature." I fear that this is precisely what I was suggesting. Does the linear relationship you mention correspond to a proven consequence of physics laws? or is it an observed phenomenon? Unfortunately, I do not have access to the paper you cite. With respect to the degrees of uncertainty. I understand that there is a normal distribution involved, but I still maintain that the degree of uncertainty is too high.
  16. It's the sun
    "most retroreflective signs use glass beads" Thanks, Hank.
  17. Models are unreliable
    "While there are uncertainties with climate models, they successfully reproduce the past and have successfully predicted future climate change". As someone who has built computer models based on natural data, I can make some comments on this. The models I build are based on spatial data rather than time-based data, but I suppoose the methods are similar. It is not surprising that the IPCC's climate models reproduce the past because I would think that the models are based to a large extent on past data. When I build a model I start with the basic ( past ) data values and come up with a mathematical formula which will model how these values change from place to place in 3 dimensional space. Then the formula is used to predict hundreds of "hypothetical", estimated values within the physical model limits. After doing this it will be apparent that in some places within the physical model, there are places where there exist an original (real) data value and a nearby estimated value in close proximity. The real and estimated values can then be compared to see how well the formula predicted reality. The formula can then be "tweaked" if necessary to give a better fit between real and etimated data values. This process is known as cross-validation. I assume the IPCC builds its models using historical data and carries out similar cross-validation techniques. Therefore of course the IPCC models can predict the past in a general sense. With regard to predicting future climate change, only time will tell. I think we would have to wait a minimum of say 30 years to see how the IPCC model's future predictions compares to reality. So I think it is premature to say that the IPCC models predict the future accurately. We do not know yet. However, I understand the IPCC produces lots of predictions based on its computer climate models and these show a large range of possible outcomes ( correct me if I am wrong ). Therefore, if this is the case, which IPCC model do we take as its prediction of future climate ? Therefore in summary, with regard to your claims quoted above, my responses are : 1. Yes the IPCC models would reproduce the past - that is what the models are based on. 2. It is too early to tell if the future prediction of climate change is correct, but which prediction are we talking about, there are many.
  18. There is no consensus
    Chris, the graph I mentioned above can be found at www.junkscience.com/MSU_Temps/Warming_Look.html#RSS It is the graph at the bottom of the page on the left. Actually the Y scale does show the temperature as an anomaly rather than an absolute figure. I had intended to change this, but I could not do so. However, if you look at the graph and assume the 0 mark on the Y scale is say 16 degrees, you can see that the global temperature in 1856 was about 15.8 degrees and "now" ( say year 2005 on the graph ) the temperature is about 16.4 degrees. On the same graph is shown the amount of CO2 in the atmosphere for the same time period. The source of the data is shown on the graph. I think this graph gives a better perspective of the changes in temperature and CO2 over that time period. The website also gives some good examples of how you can influence the wiewer of any graph by changing the scale of the graph.
  19. There is no consensus
    Thanks for your comments Chris. The data I look at does come from reputable sources like NOAA, Hadcrut and GISS. Often the way the data is presented as graphs puts a certain "spin" on the data depending on what the author wants to show. I did come across one interesting graph which shows the apparent increase of global temperature with time which is not plotted in the usual form of anomalies from an arbitrarily selected base-case. On the same graph is plotted the amount of CO2 in the atmosphere plotted as a function of its % contribution to the atmosphere. This graph shows the global temperature / CO2 data in a more realistic perspective. I will post the graph for you to see when I relocate it. Regarding consensus in science, my main point was that in the case of global warming / CO2 studies, by the very nature of what is being studied (very small changes in a massive and complex climate system about which we understand little and then projecting these relationships into the future) there is considerable room for doubt regarding the findings of the IPCC. The UN and world governments apparently intend to spend hundreds of billions of dollars combatting global warming based on some very shaky temperature trends. It is of some concern therefore that the "consensus" which is being touted is a consensus apparently within the IPCC ( UN ) itself. This is the same group that presents the climate data and which is pushing for massive expenditure to combat so called climate change. There is an obvious conflict of interest here and to talk about a consensus on man-made global warming within the IPCC (UN) under such circumstances is rather circular logic. Of course there would be consensus within the IPCC on this subject. The very existence of the IPCC relies on the supposed threat from man-made global warming. It is a bit like asking the National Rifle Asoociation if there is a consensus within the NRA that people should be allowed to own guns. In the wider scientific community there exists considerable skeptism regarding the claims of the IPCC.
  20. There is no consensus
    hmmm, my last post didn't post properly, here it is again... re #154 Neilperth
    The sad thing about this debate is that it seems just about impossible to obtain any raw, unbiased data on the subject. There are so many sources of temperature data for example and many sets of data have been adjusted for one reason or another.
    Well yes there are many sources of temperature data. There is the temperature data compiled by NASA GISS [*], by the UK Hadley Centre [**], by the NOAA [***], there are sea surface temperature data from direct measurements and from satellites. There is the temperature data from the US Climate Reference Network [****]. One can even construct a temperature record by analysis of the retreat of mountain glaciers [*****]…and so on…. These all lead to a rather similar conclusions with respect to local and global scale warming of the last century. I'm not sure what kind of temperature data you want! We do seem to have quite a lot of it. Of course many scientific measurements are adjusted. However we can if we want to look at some unadjusted data sets (e.g. the NASA GISS temperature data with all of the adjusted urban sites removed), or a subset of the US surface measures based only on the "best" set of stations, as described here [******]. Again, these lead to very similar conclusions as those derived from the full datasets.
    Therefore for every "real " graph you post on your website , I can find another apparently "real" graph based on real data which contradicts your graph. So where does that leave us in trems of finding the truth about global warming?
    That's an interesting point. I assume that, as a scientist, you obtain much of your information on scientific issues from the scientific literature and from well-validated sources like the data repositories of NOAA, NASA and such like. Thus you are bemoaning the abundant misrepresentations of the science that exists on the internet..yes? Assuredly there is loads of rubbish on the web (a few posters on this site occasionally bring it to our attention!). Obviously "finding the truth about global warming" involves being rather sensible about data sources – but I'm sure as a scientist you practice that. I guess a good way of assessing your "apparently "real" graph based on real data which contradicts your graph", would be for you to post some examples. Your points are interesting with respect to "consensus" (the subject of this thread) and it does bear on the question why some rather large "chunks" of the general public in the US are poorly informed (and rather astonishingly, seem actively to choose to be poorly informed) on some rather straightforward scientific issues. That's a whole other subject! [*] http://data.giss.nasa.gov/gistemp/ [**] papers describing Hadley Hadcrut methodologies here: http://www.cru.uea.ac.uk/cru/data/temperature/#sciref [***] http://www.ncdc.noaa.gov/gcag/index.jsp [****] http://www.ncdc.noaa.gov/crn/ [*****] J. Oerlemans (2005) Extracting a Climate Signal from 169 Glacier Records Science 308, 675 – 677 abstract: I constructed a temperature history for different parts of the world from 169 glacier length records. Using a first-order theory of glacier dynamics, I related changes in glacier length to changes in temperature. The derived temperature histories are fully independent of proxy and instrumental data used in earlier reconstructions. Moderate global warming started in the middle of the 19th century. The reconstructed warming in the first half of the 20th century is 0.5 kelvin. This warming was notably coherent over the globe. The warming signals from glaciers at low and high elevations appear to be very similar. [******] http://www.skepticalscience.com/Is-the-US-Surface-Temperature-Record-Reliable.html
  21. There is no consensus
    re #154 neilperth
    As an Earth Science scientist with 40 years experience and as someone who has written technical papers and reviewed others, I think it is misleading to talk about consensus in matters of science.
    It's an interesting point, and there's no doubt that the notion of "consensus" in science has been usurped by some rather dubious self interests. However, it is useful (since the question does occasionally arise!) to test informed opinion in relation to a specific scientific issue. This is obviously important on medical issues, for example, where best practice can be assessed in relation to clinical treatments and outcomes, and a consensus formulated based on the evidence. I would have thought one could similarly assess the consensus on specific matters relating to Earth Science. For example, I'm sure informed opinion would reveal rather strong consensus on the following specific issues: 1. the origin of the ice age cycles of the last several hundred 1000 years. 2. the formation of the Alps 3. The reason that Scotland is slowly gaining altitude while Southern England is sinking somewhat. (etc., one could obviously come up with many, many examples). Of course these aren't issues that are particulalry amenable to political misrepresentation (outside the creationist community anyhow), and so one doesn't generally hear people whining about "consensus", and pretending that these issues are merely matters of "opinion" amongst a set of scientists! So if one is honest and careful over the semantics of "consensus", it's a rather useful concept in science, and indeed in the communication of science to the general public....
  22. There is no consensus
    re #153 Yes, that's well said Ex Scienta Vera (your comments on the semantics of the word "consensus"). I think your comments constitute a rather obvious statement of the meaning of "consensus" in the scientific arena, namely that it relates to an informed, critical and tested asessment of the evidence. In other words a scientific consensus arises when the evidence on a particular subject becomes sufficiently strong that a broadly consistent informed opinion arises. Of course those that wish to manufacture an impression of uncertainty in scientific fields love "arguments" based on mangling semantics, and in this particular case it's very common to read assertions that "consensus" is something like a body of opinion that is chosen based on some sort of undefined preference, much in the way I and a group of friends might come to a "consensus" on what film we should go and see tonite! This is very widespread and examples can be found all over this website. Here's an example in a recent thread: " If hypotheses A & B are equally likely to be true(based on the evidence), then the fact that most scientists believe A to be valid and most plumbers believe B to be valid, doesn't mean that we should take the *beliefs* of scientists to be more likely true." Good, yes?! Of course if two imaginary undefined hypothesed are "equally likely to be true (based on the evidence!)" then why should we believe the opinions of anyone in particular? However that's obviously not how a scientific consensus arises. First of all we have to define exactly what the consensus refers to specifically, and having done this we could (if we wanted to) assess the evidence base from which that particular consensus was informed. We generally find that a strong consensus has a strong evidence base. Pretty obvious really.
  23. It's the sun
    Might be worth pruning this thread and moving some of the stuff to a background file, else it's just going to keep growing with tangential stuff (most retroreflective signs use glass beads that work the same way moisture does: http://www.trafficsign.us/signsheet.html) Not to mention the stuff that completely misses the mark but keeps whizzing by over and over.
  24. It hasn't warmed since 1998
    Based on the data and graphs shown on this website ...www.climate4you.com ( under the section " Global temperatures" ) there appears to have been little or no global warming since about 2003. Observations based on the various graphs show according to my "eyeballed" interpretation : University of Alabama data - No warming since 2003. RSS - No warming since 2003 Hadcrut3 - No warming since 2003 NCDC - no warming since 2003 GISS - no warming since 2003 The temperature data on these graphs show a flat or declining trend from 2003 to the present. By "flat" I mean varying within less than say 0.05 of a degree from 2003 to 2007, which I would argue is well within the accuracy with which we can measure the global temperature of the Earth. Also bearing in mind that we are supposedly talking about and looking for the IPCC"s "catastrophic" global warming trend here. After 2007, the global temperatures as shown on these graphs seem to decline more abruptly. Now my questions are: does anyone disagree with the data and trends shown on these graphs ? Does anyone disagree with my observations - and why ? I note also that the graph posted above ( figure 2 ) also shows a flat temperature trend since 2002.
  25. There is no consensus
    As an Earth Science scientist with 40 years experience and as someone who has written technical papers and reviewed others, I think it is misleading to talk about consensus in matters of science. A scientific hypothesis has to stand or fall on the data and evidence which supposedly supports that hypothesis. Comments by Al Gore to the effect that "the debate is over, we have a consensus" only go to show his lack of knowledge about science and perhaps throw some light on the political nature of the global warming debate as opposed to its scientific merits. The sad thing about this debate is that it seems just about impossible to obtain any raw, unbiased data on the subject. There are so many sources of temperature data for example and many sets of data have been adjusted for one reason or another. Therefore for every "real " graph you post on your website , I can find another apparently "real" graph based on real data which contradicts your graph. So where does that leave us in trems of finding the truth about global warming? In future I will be posting some speific questions for you, but for now, I would like to make these few general observations based on my experience. 1. Climate can change over time due to natural causes - I don't think you would have a problem with this statement. I therefore scratch my head in disbelief when people talk about combatting climate change as if a changing climate is something new and has to be stopped. 2. The IPCC ( UN ) is a political organisation and the reports of the UN naturally reflect the in-vogue political beliefs prevalent at the time. Remember the hole-in- the-ozone-layer crisis? Whatever happened to that ? So it is even more important to look closely at any claims made by the IPCC. The data on which their claims are based have to be scrutinised very carefully. I must say that to date I have not seen any hard data to show that the earth is warming at an unusual and alarming rate. And even less evidence to show that this is caused by man-made CO2 emissions. 3. There are many tens of thousands of reputable scientists, including some who used to work on the UN climate change panel, who are skeptical of the IPCC's claims on global warming. In my field of expertise, amongst my colleagues, most are skeptical of the IPCC's claims, but, interestingly, few will speak their mind publicly on this matter because it is not seen as politically correct.It could also adversely affect their careers. 4. Scientific theories can be falsified and in the case of the IPCC's claim regarding global warming, I believe this claim can be and has been falsified even using the IPCC's own data. However when this is done the global warming supporters reply with statements like " you should not have used the unadjusted satellite temperature data. You should have used data set X or data set Y " ( depending on what result they want to show ). The mere fact that there does not seem to be one definitive and acccepted set of temperature data shows how difficult it is to come up with a real value for the average global temperature to within say 0.5 degrees of accuracy let alone explain the cause of any such minor anomalies. Yet these are the sorts of minor anomalies that the IPCC is using to justify its claim of catastrophic man-made global warming. Not forgetting that the IPCC itself also adjusts the original data for various reasons. These adjustments alone can be of a similar size to the temperature anomalies which are being sought.
  26. Philippe Chantreau at 11:58 AM on 25 September 2009
    Some Skeptical Science housekeeping
    Thanks again for your good work John. I have found many interesting articles through your site. All the improvements are quite welcome.
  27. Measuring Earth's energy imbalance
    Manuel #26, let's put it another way -- if you were a stock broker and you said you weren't very certain about a bunch of stocks, but one you were very certain of should increase in value from 60% to 240% over the next five years, would you have any takers? [I'm not arguing that this is a good analogy. But I think it's just as good as yours.]
  28. Measuring Earth's energy imbalance
    re #26
    A strong "quantitative" correlation between two variables can serve as an indication to try and find a relation between them. It does not prove a relation indeed exists. I am sure you agree with me.
    Yes that's fine as a general philosophy Manuel. However we often have independent evidence of causality (I'm using "causality" in place of your "relation"). For example (despite the efforts of a separate set of scientific misrepresenters!), we know that the statistical correlation between lung cancer and ciggie smoking indicates a causality since we can examine the lung cells of smokers and determine the carcinogen-induced DNA damage that leads to loss of cellular control of unconstrained proliferation. A similar case may be made for the correlation between hugely enhanced atmospheric CO2 level and enhanced surface temperature. Simply put, the correlation is pretty much what we expect from the known properties of CO2 as a greenhouse gas, our understanding of the greenhouse effect and a rather large amount of evidence form empirical analysis of paleodata on the relationships between atmospheric CO2 levels and earth surface temperature. So while the observed correlation doesn't prove causality, it is highly consistent with the expectation of causality, and clearly one should not leave out pre-existing empirical and theoretical understanding from the analysis of correlations when addresing causality.
    With respect to the degrees of uncertainty involved in the issues we are discussing: It is huge. As an example, the last IPCC report says that total anthropogenic radiative forcing has a 90% confidence of being between 0.6 to 2.4 (with a central value of 1.6). That's a 4x factor between the lowest and highest values, and nearly 3x between the lowest and medium.
    That's not quite right. Remember that the likelihood of the "correctness" of a particular value in a normal (Gaussian) distribution falls as one moves away (in either direction) from the most likely value. So while the central value has (by virtue of the mathematics of Gaussian distributions) a probability near 0.7, the 90% confidence level values in the wings of the distribution have a probability near 0.1 or less. And of course uncertainty works in both directions. So while one might feel relieved by the possibility that a rather low anthropogenic radiative forcing might apply in reality (with very low probability), we have to accept the same probability that an anthropogenic radiative forcing on the high wing of the distribution is equally likely. In fact the high end of the distribution of anthropogenic radiative forcing is considerably less poorly constrained, and in fact recent evidence indicates that the probabilities of anthropogenic radiative forcings on the low side are less likely than considered to be the case in the rather conservative IPCC assessment reports of 2007. Of course talking about normal distributions is unsatisfactory without actually looking at them! A recent paper analysing the reduction in uncertainty in anthropogenic radiative forcing is cited below. Figure 1 of this paper illustrates the Gaussian distribution defining the probabilities of values of anthropogenic radiative forcing, and gives a much better idea of what the error range actually means with respect to the likelihoods of particular values of the anthropogenic radiative forcing. Unfortunately I haven't been able to find a freely downloadable version. J Haywood and M. Schulz (2007) Causes of the reduction in uncertainty in the anthropogenic radiative forcing of climate between IPCC (2001) and IPCC (2007). Geophys. Res. Lett. 34, L20701, doi:10.1029/2007GL030749 Abstract: Mechanisms that drive climate change are quantified by the radiative forcing which is the perturbation to the global energy balance of the Earth/atmosphere system. These mechanisms may be of anthropogenic or natural origins and each has an associated level of scientific uncertainty. Until recently, even the sign of the anthropogenic radiative forcing has been in doubt because strong, poorly quantified negative radiative forcings such as those from aerosols act to oppose the strong, well quantified positive radiative forcings from well mixed greenhouse gases. We present an analysis of the probability distribution function of the anthropogenic radiative forcing for the individual forcing mechanisms identified by IPCC (2001) and IPCC (2007). We conclude that significant progress in reducing the uncertainty of the anthropogenic radiative forcing has been made since IPCC (2001). The single most important contributor to this conclusion appears to be the reduction in the uncertainty associated with the aerosol direct effect, followed by the provision of a best estimate for the aerosol cloud albedo indirect effect.
  29. Measuring Earth's energy imbalance
    Re #13 and #17 Manuel, your interpretation of the linearization of the relationship between temperature change and radiative forcing as used by Murphy et al (2009) (their equation 1 that you reproduced in your post #13) isn't correct. Thus the concern you raise in your post #17 is misplaced in this instance. Your suggestion that the increase in radiation is proportional the the fourth power of the increase in temperature (Stefan-Boltzmann law) is fine, but not relevant to what Murphy et al (2009) are investigating. The Stefan-Boltzmann law relates the radiation emitted from the surface of a body at a defined temperature and does indeed have a fourth power relationship. However Murphy et al (2009) are estimating the radiative forcing F which is essentially the net radiation once the energy balance is "accounted" (i.e. top of the atmosphere radiation in minus radiation out). It turns out that this net radiation does have a generally linear relationship with the change in the earth's surface temperature (more sensibly, the earth's surface temperature change is roughly proportional to the radiative forcing). This could be investigated further by reading the following paper: Gregory JM and Forster PM (2008) Transient climate response estimated from radiative forcing and observed temperature change. J. Geophys. Res. 113, D23105 Abstract (my highlights): Observations and simulations (using the HadCM3 AOGCM) of time-dependent twentieth-century climate change indicate a linear relationship F = rho Delta T between radiative forcing F and global mean surface air temperature change Delta T. The same is a good description of Delta T from CMIP3 AOGCMs integrated with CO2 increasing at 1% per year compounded. The constant "climate resistance'' rho is related to the transient climate response (TCR, Delta DT at the time of doubled CO2 under the 1% CO2 scenario). Disregarding any trend caused by natural forcing (volcanic and solar), which is small compared with the trend in anthropogenic forcing, we estimate that the real-world TCR is 1.3-2.3 K (5-95% uncertainty range) from the data of 1970-2006, allowing for the effect of unforced variability on longer timescales. The climate response to episodic volcanic forcing cannot be described by the same relationship and merits further investigation; this constitutes a systematic uncertainty of the method. The method is quite insensitive to the anthropogenic aerosol forcing, which probably did not vary much during 1970-2006 and therefore did not affect the trend in Delta T. Our range is very similar to the range of recent AOGCM results for the TCR. Consequently projections for warming during the twenty-first century under the SRES A1B emissions scenario made using the simple empirical relationship F = rho Delta T agree with the range of AOGCM results for that scenario. Our TCR range is also similar to those from observationally constrained model-based methods.
  30. Measuring Earth's energy imbalance
    Chris, "That seems a very strange (and false) emotionalization of a quantitative analysis!" I was just trying to characterize the two most extreme factions of the AGW debate I have met. On the one hand those that say "It's [only] the sun" on the other side the most exaggerate proponents of AGW that say "CO2 is gonna kill us [we have no time left to act]". My personal view, as I have already expressed is that both extreme views are probably wrong, and I am sorry if my phrase sounded like an insult to you. With respect to correlations: A strong "quantitative" correlation between two variables can serve as an indication to try and find a relation between them. It does not prove a relation indeed exists. I am sure you agree with me. A weak "qualitative" correlation is just the expression of the desires of the person that makes the graph. This reminds me of what a coworker told me many years ago. His first employment, as an intern in an investment bank, was mainly to try and find the specific kind of deals for which his bank was the market leader. He succeeded quarter after quarter. (And, yes, the "bank" was a small local operation, more a financial boutique than a real bank) With respect to the degrees of uncertainty involved in the issues we are discussing: It is huge. As an example, the last IPCC report says that total anthropogenic radiative forcing has a 90% confidence of being between 0.6 to 2.4 (with a central value of 1.6). That's a 4x factor between the lowest and highest values, and nearly 3x between the lowest and medium. I used to make my living selling companies. If I had told my clients that their businesses were valued something between 1 and 4, most probably around 3 ... I wouldn't have had many clients, would I?
  31. Measuring Earth's energy imbalance
    Tom, thanks again but wouldn't a more accurate analogy be at equilibrium - the water being added is equal to that which is leaving through a hole. AGW equivalent - the hole is decreasing in size, but the water being added stays the same. So the bucket starts to fill up. The speed of water through the hole increases but it is not enough to compensate. ?
  32. Measuring Earth's energy imbalance
    A flaw in my metaphor of water-bucket for energy-Earth is that there are no laws of physics compelling the bucket system to reach equilibrium. The hole's size and position, the bucket's size and shape, the rate of water input, would have to all be exactly the right combination for the system to stabilize at some high enough rate of water spurting out the hole, to prevent the bucket from overflowing. It can happen, but it's unlikely. In contrast, objects are constrained by laws of physics to radiate more the hotter they are, until they put out as much as they get in.
  33. Measuring Earth's energy imbalance
    Re: #22 canbanjo Poke a small hole in the bottom of a bucket. Put a water hose in the bucket. Turn on the water so the amount of water going into the bucket is slightly more than can leave through the hole. Over time, the amount of water in the bucket will increase, which will increase the weight of the water, which will increase the pressure of the water at the bottom of the bucket. The higher pressure will push a larger quantity per second of water through the hole. Result: The input is constant, but the amount of water in the bucket increases at the same time the amount of water escaping from the bucket increases. The extra water going out of the bucket is a fraction of the water that is accumulating in the bucket.
  34. Measuring Earth's energy imbalance
    Tom, thank you for trying to explain. Unfortunately I come back to the fact that the earth is heating up, that energy is coming from outside, so overall there is more energy coming in than is going out. the energy coming in is not increasing, so the energy going out cannot be increasing. there must be something else to this that is not being explained.
  35. Measuring Earth's energy imbalance
    Re: #20, canbanjo Greenhouse gases don't trap all the outgoing radiation. They trap some, which causes the temperature to increase, which causes the Earth to "try" to radiate more energy. Only some of that increased radiation is trapped by greenhouse gases; the rest escapes. Of course, the portion of that increased radiation that is trapped, raises the temperature even more, which in turn causes the Earth to "try" to radiate more, and so on. But that process does not run away; the increases in attempted radiation and in trapping are only fractional, so their absolute amounts become progressively smaller until they become effectively zero; that's equilibrium. But equilibrium lasts only if the amount of greenhouse gas stops increasing. Since greenhouse gases keep increasing, equilibrium is a moving target.
  36. Measuring Earth's energy imbalance
    I still don't get the idea of increased radiation into space due to to the earth becoming hotter. If the earth is getting hotter due to greenhouse gases trapping outgoing longwave radiation, then there must be a decrease in outgoing radiation not an increase. The relative increase would only occurr once the system is returning to equilibrium.
  37. Is the U.S. Surface Temperature Record Reliable?
    Analysed another random cell (6x6 degrees)in central USA using 4 rural stations. The ten-year trend varied from 0.08/0.03/-0.027/0 (zero) giving a mean value of 0.021C. Nowhere near the 0.2C per decade expected. Again a lack of correlation within the grid which seems to counter the argument that the trend is well correlated at great distances. Or maybe I just struck lucky.
  38. The growing divide between climate scientists and public opinion
    Have a look at "Battle of the Jaywalk - May 2005 2/2" on You-tube. This is the FINAL of a general knowledge test in the USA. Is this the kind of ordinary 'Joe Public' person asked to give their opinion as to whether human activities contribute significantly to climate chamge? Heaven help us if it is. Shawnhet, your post hits the nail firmly on the head. It seems to be getting towards the stage where if you challenge the degree of the effect ( not the effect itself) you are a 'denier'.
  39. Is the U.S. Surface Temperature Record Reliable?
    #33.."But no, the loss of data from Russia, China etc doesn't necessarily affect the answers we get...what makes you think it does?" So let's pretend I own 60 supermarkets ( I wish) and each store downloads sales information on a weekly basis so that I can track sales of each item for re-ordering purposes ( central buying) and also so I can construct a profit/loss account. The computers at 20 stores go down and I don't replace them. How do I know what to order and how much? How can I construct a P/L account for the company? Answers...I cannot do either with the accuracy I used to have. I will over/under order and cannot determine the current financial state of the group. If you multiply the stores up to 1000 and I lose data from 500 ( roughly equivalent to the reduction in weather stations) the result is the same and I am left with only guesswork.
  40. Is the U.S. Surface Temperature Record Reliable?
    On 1200km cells..........went back to GIStemp and took annual mean temp data from 6 stations within a 1200km grid. Calculated the temp anomaly for each station over a time period of 10 years (1980-1989). 3 stations had an anomaly of 0.14- 0.15 C, the other 3 had anomalies of 0.03/0.08/0.10C The average anomaly within the grid using just these stations is thus 0.106C which is half of what is expected. So I don't see correlation within a grid, let alone between grids. But I will do some more checking.............
  41. Is the U.S. Surface Temperature Record Reliable?
    No you're pursuing a non-sequiter Mizimi. Yes, insufficient data and poor coverage affects the end result. That is obvious. But no, the loss of data from Russia, China etc doesn't necessarily affect the answers we get...what makes you think it does? You certainly can't draw that conclusion from your simplistic perusal of 16 stations. These issues have to be analyzed properly. Raising theoretical issues based on simplistic analysis and then concluding that these issues apply without showing evidence that they do is false argumentation. In fact it's quite apposite in the context of this thread, since that selfsame false logic is the fundamental flaw of Mr Watt's misanalysis (or non-analysis) of the US surface temperature record.
  42. Measuring Earth's energy imbalance
    Manuel, it's worth going back to your explanation 2 since that's what you're disputing (it seems you raised it just to knock it down!) Explanation 2:
    200 of actual heat increase = 100 coming from the increase in solar radiation + 1,600 from greenhouse gases effects – 300 from stratospheric aerosol effects – 350 from outgoing radiation that really isn’t going anywhere because of the greenhouse gases – 950 from mostly unknown (or not yet quantified) causes.
    Two things that might help: i. The "350 from outgoing radiation" really is going somewhere. It's escaping from the atmosphere into space. I'm pretty sure this does not refer to long wave IR emitted from the earth's surface, but to the enhanced emission of IR to space as the climate system tends towards equilibrium with the enhanced (greenhouse) forcing (see my post #7). I welcome input on whether I've interpreted that correctly. ii. The 950 isn't mostly unknown nor "not yet quantified". It's largely aerosol direct and indirect effects, and these have been quantitated (see e.g. [***]). Of course there is signifcant uncertainty in these analyses. [***] V. Ramanathan & G. Carmichael (2008)Global and regional climate changes due to black carbon, Nature Geoscience 1, 221 - 227 (2008) Ramanathan's analysis can be read in a similar form from this Senate committee hearing document here: http://www-ramanathan.ucsd.edu/testimonials/BlackCarbonHearing-testimony.pdf
  43. Is the U.S. Surface Temperature Record Reliable?
    No Chris, I am not trying to calculate the anomaly from 20 stations, I am showing that insufficient data and poor coverage affects the end result. A pretty obvious thing I would have thought. So that the loss of data from Russia, China at al affects the the answers we get. Defining the US anomaly with 70 stations is rather unhelpful in defining the GLOBAL anomaly if we do not have data from stations on a GLOBAL scale.
  44. Measuring Earth's energy imbalance
    Manuel, Of your two explanations, your explanation 1 is clearly incorrect (see mine and Tom’s explanation)…you agree with this. Explanation 2 is simply and unequivocably correct in the context of the paper. After all, these forcings are independent and thus an unbiased summation is the correct means of coming to a conclusion about the residual forcing and its contributions. Obviously there is uncertainty over the magnitudes of these, but that doesn’t negate the fact that an unbiased overall summation is appropriate. I’m curious about your extrapolation from the fact that the evidence very strongly supports a strong enhanced greenhouse forcing (which is very obviously much stronger than the solar forcing as indicated by a substantial evidence base), to an interpretation that explanation 2 corresponds to a "CO2 is gonna kill us" hypothesis” . That seems a very strange (and false) emotionalization of a quantitative analysis! “Qualitative correlations”. This is an interesting point. One of the difficulties with establishing attribution of forcing contributions to 20th century and contemporary warming is that the sort of “correlation” that you desire (presumably something like a mathematical/statistical linearized relationship between variables) isn’t appropriate for assessing attribution of 20th century warming to its contributing forcings. However we would be in a very sorry position if were to conclude that attribution was therefore not accessible nor robust. We can assess attribution via modelling based on known/estimated magnitudes of the forcings coupled with knowledge of climate responses and their time constants, and reintroduce a quantitative (‘though non-linear) element into the relationships. Notice that we can assess climate responses (earth temperature) and greenhouse gas concentrations with quantitative correlations of the sort you desire via analysis of paleoproxy data (e.g. as compiled, for example, here [***]) where the relationship between temperature and CO2 concentrations can be linearized since the temperature can be reasonably assumed to have come to equilibrium with the forcing in these analyses. Incidentally, although this is a semantic point, the use of the word “ correlation” certainly doesn’t imply that the correlation between variables is quantitative. Here’s a dictionary definition of the term “correlation”, and I suspect that the term is used in that sense in the page I linked to on this site in my post just above. However, as I indicated above, a quantitative analysis via mathematical modelling can be used to extract attributions of 20th century warming (rather in the manner of the quantitative analysis in the Murphy paper we’re discussing). correlation n. A causal, complementary, parallel, or reciprocal relationship, especially a structural, functional, or qualitative correspondence. [***]Royer, D. L. CO2-forced climate thresholds during the Phanerozoic. Geochim. Cosmochim. Acta 70, 5665–5675 (2006).
  45. Measuring Earth's energy imbalance
    John, Thank you very much for your reply. Re. correlation. As per my previous post, my main point is that correlations have to be taken with great care as they provide very poor basis to prove or disprove anything. Re. linear modelization. Yes, I am looking at the following formula which, as you say, refers to net radiation: N = F - lambda x Delta T + epsilon One of the concerns I have when I look at climate papers is how linear relationships are being used for phenomena which don't seem to be linear. By the way, that's also why I find suspicious linear correlations to begin with.
  46. Measuring Earth's energy imbalance
    Thank you very much for your detailed answers. I agree with Tom that Explanation 1 (corresponding to the "it’s the Sun" hypothesis) is too simplistic to be correct. But I have to disagree with Chris and maintain that Explanation 2 (the "CO2 is gonna kill us" hypothesis) is also almost surely to be incorrect, if only because of the degree of uncertainty with which the different components of radiative forcings, positive or negative, are being "estimated" or "asumed". I have to maintain "estimated" or "assumed" because few things in Climate can be really "measured" and the paper itself recognizes that the big white chunk of figure 3 is a result, not a calculation. My personal impression (which I understand has little or no value) is that radiative forcings of greenhouse gases have been overestimated. Leaving a much more manageable situation on the right side of the equation once they are adjusted to their true value (less unknown effects to be accounted for). Furthermore, many of the claims made by both sides of the debate seem to me to be too opportunistic and self-contradictory, like rising temperatures prove CO2 warming, but when they apparently stop rising, other factors should be acknowledged for, even though they weren’t considered before. By the way, I am happy to concede that on the other side it is also easy to spot bogus arguments, if only because the skeptics’ front is less organized. I am sorry Chris, but "qualitative" correlations have little or no value for me at this point. They hardly prove or disprove anything, or rather they can "prove" anything you like them to "prove". That’s why I think that the only "correct" explanation at this point is that we still don’t know enough and everybody is free to make her own bets, but please let's try to be at least consistent with the implications of our hypothesis.
  47. Global warming and the El Niño Southern Oscillation
    A rather more rigorous analysis of the contribution of generalised ocean circulation effects to 20th century temperature variation has just been published [***]: K.L. Swanson et al. (2009) Long term natural variability and 20th century climate change Proc. Natl. Acad. Sci. USA 106, 16120-16130 This analysis indicates that natural contributions (largely ocean circulation variability) have had a significant effect on 20th century temperature variability. However the nett contribution to overall 20th century warming is close to zero. Essentially ocean circulation variability made a positive contribution to early (1900-1940) 20th century warming, a negative contribution to mid 20th century warming and a positive contribution to late 20th century warming. Once the natural variability is removed the externally forced (greenhouse) contribution is manifest as a continuous accelerating warming. [***] http://www.pnas.org/content/early/2009/09/09/0908699106.abstract abstract: Global mean temperature at the Earth's surface responds both to externally imposed forcings, such as those arising from anthropogenic greenhouse gases, as well as to natural modes of variability internal to the climate system. Variability associated with these latter processes, generally referred to as natural long-term climate variability, arises primarily from changes in oceanic circulation. Here we present a technique that objectively identifies the component of inter-decadal global mean surface temperature attributable to natural long-term climate variability. Removal of that hidden variability from the actual observed global mean surface temperature record delineates the externally forced climate signal, which is monotonic, accelerating warming during the 20th century.
  48. Measuring Earth's energy imbalance
    Re: #13 by Manuel: Manuel, your Explanation 1 is incorrect, because all those non-solar positive and negative forcings you say the author "assumed," instead are real, concrete, physical, measured phenomena that must be accounted for just as much as the solar forcing and the resulting temperature must be accounted for. Even if the global temperature was not increasing, the exact same analysis would be done using empirical facts for all those forcings, and in that non-warming case the accounts would have to balance. Your misunderstanding is understandable, because the popular media and especially the denialist ones try to create the impression that climatologists noticed that the temperature increased and in response started guessing at what might be causing it, without any empirical evidence. It's like your home budget. Receipts for spending, and paychecks, all are empirical facts that must be accounted for in the overall balance. Yes, there is uncertainty about some of your spending, and maybe about some of your income if you didn't keep good records of your garage sale. But you can't ignore the actual receipts and paychecks.
  49. Is the U.S. Surface Temperature Record Reliable?
    Well yes Mizimi....it's obvious that you can't determine the global temperature anomaly trend from 16 sites. I don't really understand your point. In post #25 you stated that you "would not consider 100 stations since 2001 as being significant" in the context of the US Climate Reference Network that I described in posts #22 and #29. However now you're attempting to determine the global anomaly from 16 sites which is a surface density of around 0.3% of the USCRN. So how can an analysis of 16 sites be sufficient in your post #30, when you consider a density equivalent to ~6500 sites worldwide to be insignificant for determining a temperature anomaly trend? Clearly there is a requisite number of sites for adequate determination of a global temperature anomaly with acceptable statistical uncertainty. It's obviously greater than 16. The fact that the US temperature anomaly trend can be defined pretty well with 70 sites (see Figure 2 in the top article), suggests that a number well below 6500 is enough. Making any further conclusions requires consideration of the vast multitude of data and analyses in the published science where these issues have already been addressed at length (see links in my post #28).
  50. Measuring Earth's energy imbalance
    Manuel, your "explanation 2" has to be the correct one in the context of the study. The negative forcings (note these are not "negative feedbacks" as you describe them), are individual components of forcings, the summation of which gives the total forcing (that yields the cumulative 200 x 10^21 J). The total greenhouse gas-induced forcing is obviously much larger than the solar one, and any negative forcing acts to counter all of the positive forcings – one can't single out a single forcing (solar) and consider that its contribution is somehow left "unopposed" by negative forcings. (incidentally, and rather in line with the annoyingly vague descriptions in the paper, there is no reference to the source of the solar forcing contribution. The published data indicate that solar contributions have not only been very small since the 1950's, but have been in a cooling direction for around the last 20 years. However Murphy's data [Fig 2 above], indicates a (admittedly small) solar contribution that continues to increase during the 15-20 years up to 2004. The authors refer to global dimming effects, and I wonder whether these (i.e. recovery from "dimming") is included in the solar contribution…the authors give us no insight on this!). On you specific question #1: Firstly we should be careful how we're using the term "correlation". It's not a mathematical/statistical correlation, and one shouldn't be expected in the CO2/surface temperature relationship. At best we can say that in line with the rather slow early 20th century increase in greenhouse gas, the surface temperature rose slowly, and following the very rapid rate of increase in CO2 emissions from around the mid 60's the temperature increase has been faster. But the effects of CO2 on surface temperature are mixed in with the effects of all the other forcings [***], and are further "discorrelated" by lags in the response times of the various elements of the climate system (atmosphere, land, ocean surface, ocean depths), and so strict "correlations" in the statistical sense aren't expected. That there is a qualitative "correlation" as described by John Cook here….. http://www.skepticalscience.com/The-correlation-between-CO2-and-temperature.html ….is due to the fact that increasing the greenhouse effect does cause the Earth's surface to warm, and there haven't been any truly humungous events (massive changes in solar outputs or truly dramatic volcanic events etc.), that have overcome the dominant greenhouse contribution. In any case even 'though the tiny atmosphere/surface ("tiny white sector of figure 3") is indeed tiny with respect to the CO2 effect ("big gray sector on figure 2"), the ocean effect does clearly "correlate" with the CO2 effect, and we expect the land surface effect to "correlate" with the ocean effect since the latter has a strong influence on the former. So I don't think the "correlation" (using the term broadly!) is unexpected. [***] a very interesting paper on this is just published in PNAS – it's very apposite: http://www.pnas.org/content/early/2009/09/09/0908699106.abstract
    Response: I queried the author re where his solar data comes from, it comes from Gregory and Forster (2008). Re the PNAS paper you link to, I just received a copy about a week ago and plan to do a post on it shortly.

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