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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 69001 to 69050:

  1. Climate Solutions by Daniel Bailey
    paul D. Carry a lawnmower? My little mini that I treasured in the early 70s could take massive things - lawnmowers, compressors, food for 40 people for a weekend. Made the proud owners of large cars weep. How? Just remove the front passenger seat. Much easier access than in the largest boot. It's all about design. And spanners. (But not modern safety standards, unfortunately.)
  2. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    Jfyre11 @56, Dana's claim quoted by you represents IMO a summary of the information in this paper quoted as reference 14 in Schmittner et al 2011. That paper that:
    "In fact, our model has been used, and is still being used, as a tool to examine the sensitivity of a particular process or subcomponent model across a wide range of parameters, in order to streamline the process of improving certain components of the CCCma coupled AOGCM. The complexity of the CCCma AOGCM is such that relatively few ‘production runs’ can be conducted, leaving systematic parameter sensitivity analyses to be conducted with the University of Victoria (UVic) ESCM."
    and
    "In fact, our model has been used, and is still being used, as a tool with which to examine the sensitivity of a particular process or subcomponent model across a wide range of parameters, in order to streamline the process of improving certain components of the CCCma coupled AOGCM."
    and
    "The sophisticated sea-ice model was built and tested within the context of the ESCM and has since been included in the Canadian Centre for Climate Modelling and Analysis (CCCma) coupled Atmosphere-Ocean General Circulation Model (AOGCM)."
    These claims, IMO, support Dana's claims about the relationship between the CCCma and the UVic model. Are those claims false, or merely dated?
  3. Changing the Direction of the Climate
    Pirate, No-one is suggesting that it is possible to return to pre-industrial levels. As discussed above, we will be lucky if we can hold levels under 450. How can you imagine we could reduce to 180? If we can ever get the amount of CO2 to level out (likely to be above 450) then we can start to consider what would be a good level to end at. Now we need to decide to begin to reduce the amount of pollution we put in the atmosphere. Reducing the amount in the atmosphere is very difficult because when you reduce the atmospehric amount, more CO2 comes out of the ocean in response. Have you really not considered this before?
    Response:

    [dana1981] pre-industrial is 280, not 180ppm.  But you're correct that there's virtually nil chance of us getting anywhere close to that, unless we invent some technology to remove massive quantities of CO2 from the atmosphere, or something.

    The question is not warming or cooling, it's how much more warming.

  4. Changing the Direction of the Climate
    Pirate, there is no chance of CO2 dropping too low. RealClimate has the story..
  5. apiratelooksat50 at 07:33 AM on 1 December 2011
    Changing the Direction of the Climate
    If CO2 levels are successfully reduced to pre-industrial levels, what responses in global temperature should be expected and how soon? If we are successful in reversing a rising temperature trendline, at what point do we want it to level out? Furthermore, at what point do we begin to worry about it getting too low?
  6. Changing the Direction of the Climate
    I have to agree, while 450 ppm is technically feasible, we clearly don't have the political will to make it happen. But the IEA is just discussing how we could do it, if we had the will. Realistically I don't see how we'll avoid blowing past 2°C, which is a scary thought.
  7. Philippe Chantreau at 06:48 AM on 1 December 2011
    Climate Solutions by Daniel Bailey
    What you say about the UK applies even more in the US Paul. The epidemic of obesity afflicting the country has turned into an epidemic of enormity, and beyond people and pets, it now also affects automobiles.
  8. It's the sun
    I agree - looks like more cycle-fitting. If this has any real scientific merit - publish it in peer-reviewed literature not a book.
  9. Changing the Direction of the Climate
    The IEA is pipe dreaming if they think Emissions will peak and began to decline in 2017. I see emissions peaking in 2035 or 2040- when C02 will have passed 450ppm. At this point a 3 degree rise C is certainty- we can only hope we do not go beyond that.
  10. The Debunking Handbook: now freely available for download
    lakshmanok @ 35 - Yes, we've had a few words about this, but haven't come to a solution yet. Thanks for pointing out the contradiction, it might spur action.
  11. IEA CO2 Emissions Update 2010 - Bad News
    dakiller6 - to convert from carbon figures to carbon dioxide, multiply by 3.67.
  12. The Debunking Handbook: now freely available for download
    Nice handbook, but if that thermometer on your home page (the one listing the most common climate myths) doesn't reinforce climate myths, I don't know what does! Please follow your own advice :) http://not-that-sane.blogspot.com/2011/11/how-to-debunk-myth.html
  13. Changing the Direction of the Climate
    According to his website, "Michael Den Tandt is a national political columnist for Postmedia News, publisher of the National Post, Ottawa Citizen, Montreal Gazette, Calgary Herald, Vancouver Sun and Halifax Chronicle-Herald." Not a reputable scientific source.
  14. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    dana1981 writes: "neal - it does appear that the models are related. For example, the UVic sea ice module was included in CCCMA, and the UVic model is extensively used in developing and testing the CCCma model. But it's not a critical point, and if it exaggerates the relationship between the two (which is unintentional, if so), I don't have a problem with removing that section." Thank you for removing that section, but what you say above is also false. I am a CCCma scientist and have extensive experience with the CCCma models, and well as with the UVic model and many other models. These models share some common features, as do all climate models -- but beyond that they have been developed and tested independently of one another. This is not a big deal in terms of what you're debating in your post, but I correct you all the same.
  15. Peter Hadfield addresses the recent email release
    Ditto - what tmac57 said.
  16. It's the sun
    the end of comment 914 indicates Don Gaddes compiled these numbers in 1990. I am curious how accurately his calculations predicted the global average temperature for the years 1990-2011.
  17. The Debunking Handbook: now freely available for download
    Apologies, I meant Page 8 (eight). Second to last paragraph, just before the bibliography, reads, The gap created by this debunking is the question “how can there be a 97% consensus if 31,000 scientists dissent?” This gap if filled by explaining that almost all the scientists in the Petition Project are not climate scientists. Please replace "This gap if filled..." with "This gap is filled..."
  18. The Debunking Handbook: now freely available for download
    I would like an ebook format (epub) too. I would pay for it.
  19. It's the sun
    Don Gaddes - Well, that's a lot of numbers. But do they mean anything? The temperature of the Earth climate is determined by the amount of energy in it - which in turn is driven by the rate of energy in (sunlight, throttled mostly solar output and Earth albedo) and the rate of energy out (throttled by temperature, IR emissivity of Earth to space). You seem to be claiming that current temperature changes are driven by cyclic phenomena, not CO2 and other greenhouse gases. Unless these 'cycles' determine the rate of energy entering or leaving the Earth's climate, somehow modifying insolation (in ways that are not currently detected by TSI studies), albedo (again, in ways not currently detected), or IR emissivity to space, they are essentially "climastrology", "numerology". Tamino has discussed this exercise, and has most appropriately labeled it Mathturbation. Given sufficient data and imagination, it's possible to fit any natural phenomena to 'cycles', but unless there is a physical basis affecting energy rates you are looking at correlation without causation. How do these various cycles physically affect the energy balance of the climate - in some measurable fashion? Without that, these 'cycles' are simply a pointless intellectual exercise...
  20. Changing the Direction of the Climate
    Thanks
  21. Economic Growth and Climate Change Part 2 - Sustainable Growth - An Economic Oxymoron?
    perseus : I remember the estimates of Jackson in the chapter on the ‘myth of decoupling’, but I cannot examine precisely this for now. I think he is globally right, but I’d like to check the rate of energy intensity gain really implemented in some models (there are probably an inverse function of substitution rate). To be sure, a 450 scenario is at least a ‘gamble’ but I agree with Tom’s answer above. Not a substantive but a pragmatic consideration: take the time necessary to reach a policy consensus on negative growth ou zero growth, and we will probably double the CO2 concentration! Bluntly put : if, in a democratic system, people were really to choose between the immediate consequences of an organized stagnation / recession and the distant consequences of a 2K or 3 K warming, I bet most of them would prefer the second option. At least in some countries and, as 15 years of climate negotiations have shown, a global consensus on solutions is requested, because local efforts (like Kyoto Protocol) didn’t produce significant effects on emissions rate. adelady : I agree, but this is probably a matter of pace and scale. Small changes will cause small debates and opposition. For bigger change, you must anticipate much more resistance IMO. And there is also the macro-economic effect of an ambitious energy transition plan. If you take for example all the direct and indirect jobs related to car use in transportation (not just the engineers and workers in production industry, but all services, products and value chain centered on car), it is uneasy to plan a revolution in one generation. At least, the hypothesis of zero social friction is a gamble !
  22. It's the sun
    My apologies if I misinterpreted DB's moderation comment @909, I did not ever see your original. I will use a more friendly tone from here on if you will do the same. The evidence you provide in @914 is not the least bit helpful without some context. It is just a Number Salad. Please provide an outline of your argument because at this point I have no idea what it is your numbers are supposed to show me.
  23. Changing the Direction of the Climate
    jimb - see our CERN rebuttal
  24. Economic Growth and Climate Change Part 2 - Sustainable Growth - An Economic Oxymoron?
    I'm not sure Tom, it may proove more expensive to deliver a near zero carbon energy system than to stop economic growth. As an Engineer I know how hard and expensive it will be to deliver this without a scientific breakthrough. It might be possible to deliver 20% at present though green energy without breaking the bank, but a 80-90% reduction for an increased economy and population is a totally different matter. The demands on materials, storage costs, design for worst case meteological conditions is staggering. If we are struggling now, you haven't seen nothing yet. Simply foregoing needless toil and rubbish is so much easier than 9 bllion people forever trying to catch up with the Jones' Neither can I see any reason why simply forgoing buying even more stuff should lead to a crisis. Reductions in economic growth have previously been driven by some underlying crisis such as war or famine, and we are talking about steady state economy not a reduction. Japan has been a steady economy and a reducing population for 20 years now yet I see no evidence of widespread suffering or lack of innovation. Sometimes it can be better to be honest and tell people straight what is necessary to do the job 'Ask not what your country can do for you - ask what you can do for your country' or fellow human or planet in this case, rather than weak promises of ever greater riches. They might actually believe that. I guess the route is to move away from GDP metric altogether and towards a quality of life index then at least you could show them real improvements, than through fantasy economic figures.
  25. It's the sun
    Yes, I was 'banned' and reinstated, with further (-snip-) warning. No, I did not try to sell anything, I offered a free pdf of the 'proofs'. (-snip-) Anyhow, here is a small taste. If you are still interested you can pursue the rest. Earth's Period (No. 1 Constant) Divided by 4 (Obliquity, No 2 Constant) = Quarter Year Multiplied by 27 (Ratio, No. 3 Constant) = 6.75 Years (Regional Drought Cycle) Multiplied by 11.028148 Yrs (Sunspot Wave Frequency, No. 4 Constant) = 74.44 Years ( Quarterly Sub-cycle of a full 297.76 year Sunspot Cycle) Divided by 4 (Obliquity, No. 2 Constant) = 18.61 years (Metonic Cycle of the Moon's Nodes.) Multiplied by 27 (Ratio, No.3 Constant) = 502.47 Years (Full Tree-ring Cycle, 3x167.49 Year Tree-ring Sub-cycles.The 167.49 Year Sub-cycle is in turn made up of 9x18.61 Year Metonic Cycles of the Moon.) Multiplied by 11.028148 Yrs (Sunspot Wave Frequency, No. 4 Constant) = 5,541.3135 Years (Which equals 2x2,770.6567 Year Glacial Cycles, See J Bray.) Multiplied by 11.028148 Yrs (Sunspot Wave Frequency, No. 4 Constant = 412,495.34 Years (=?) Divided by 4 (Obliquity, No 2 Constant) = 103,123.83 Years (Precession of 'Perehelion and Aphelion') "According to Strahler,(Ref. No.17.) the rotation rate of the Sun differentiates at a slower rate from lower to higher latitudes. It seems to me that we ought to be investigating the latitude of the Sun which is rotating at the 27 day rate." (A S Gaddes, 1990.)
    Response:

    [DB] Inflammatory tone snipped.

    "I offered a free pdf of the 'proofs'."

    If no peer-reviewed published citable sources exist your claims devolve to "climastrology".  QED.

  26. Changing the Direction of the Climate
    One reason we may end up 'wait to implement serious mitigation' may be found in op-ed pieces like the one in our local paper this morning, titled "Of course, Canada ditched Kyoto commitments". The author, Michael Den Tandt writes as follows: "The skeptical science, for years confined to the scruffy margins by the International Panel on Climate Change and its supporters, took a huge leap forward with the discovery by no less than the CERN laboratories based in Switzerland-arguably the most prestigious scientific group in the world-that fluctuations in the sun's magnetic field have a very large, perhaps dominant effect on the earth's climate." He continues "the CERN findings are steadily trickling through the blogosphere, quietly altering the political discussion everywhere..." The only thing I can think he is referring to is the CERN work relating cosmic rays to cloud formation, but I get most of my climate science from this site. Hopefully, someone more familiar with the science than I am can stop this trickling before it drowns the discussion.
  27. Peter Hadfield addresses the recent email release
    Another excellent piece of work by Hadfield.We all owe him our gratitude for fighting the disinformation that seems nearly bottomless (in more ways than one).And of course the same appreciation goes out to SkS.
  28. Climate Solutions by Daniel Bailey
    In the UK the vast majority of people don't need the types of vehicles they use and could easily make do with smaller vehicles. People make up excuses for buying a vehicle with large carrying capacity, stating things like: 'it would be really useful for carrying a lawnmower to the repair company, or for picking up some timber from the DIY store'. Yet they often only ever do this once or twice a year or even never! So the reality is they could have got the store to deliver for a fraction of the cost of the the fuel and materials needed to build and use the bigger vehicle. Yeah a few people 'need' them, but most vehicles are driven with just the driver at the wheel 90% of the time. Plus of course cars need a lot of parking space at various places to cope with the probability of someone needing a parking space.
  29. IEA CO2 Emissions Update 2010 - Bad News
    dakiller6, the SRES tables you link to show gigatons of carbon ("GtC")... figure 1 above shows gigatons of carbon dioxide. Basically, one set of figures is counting only the mass of the carbon atoms while the other is including the two oxygen atoms as well.
  30. Peter Hadfield addresses the recent email release
    Oh...well done! Simply wizard!
  31. Climate Solutions by Daniel Bailey
    WRT living closer to work, this is not always a reasonable solution. In my case I live relatively close to my primary employer and plan to move farther away as the neighborhood is not good. My 2nd job (which I work remotely 90% of the time) is in an even *worse* area. Moving to a nicer area and commuting might be the wrong environmental choice but the right one for my family.
  32. It's the sun
    You are still posting so you are not banned (see post 911). If you want to discuss the science here then discuss the science. State your case and provide your evidence. Provide links to more details if it is too much for a single post. This is not rocket surgery, it is basic conversational skills. "Buy my book to learn the Truth" is not at all the same thing.
  33. IEA CO2 Emissions Update 2010 - Bad News
    Hello, I just registered to ask a question on this article. I am a Ph.D student on atmospheric science but my main area of research is cloud physics ('aerosol indirect effect' which is covered in IPCC WG1 report) and I am not familiar with CO2 emission (instead of concentration) statistics or anything treated in WG3 report. I found this article very interesting (and alerting!) and want to introduce this article at a forum whose main attendances are non-scientists, which is part of volunteering work for environmental movement here in Korea. My question is, why are the numbers for SRES scenarios in the Figure 1 (which is around 20~30 Gton/yr) different from the numbers of Fossil Fuel CO2 provided at the SRES website (http://sres.ciesin.org/htmls/data_list.html), which is lower than 10Gton/yr? There must be some sort of notion difference between them. If it's too much work for you to explain, a nice reference will do. Thank you.
  34. Climate Solutions by Daniel Bailey
    I would add that an area for big potential savings in energy consumption and CO2 emissions is not just what or how much you drive a personal vehicle, but how you drive it. Unnecessarily hard acceleration kills your vehicle's efficiency. One study from a dept. of the US gov't (EPA, I think) found that avoiding hard acceleration would save the average American driver (who drives like a movie stunt man on a bad acid trip) about 30%(!) in fuel consumption. Add in other obvious savings like not carrying a lot of dead weight in the vehicle, keeping tires properly inflated, not speeding, etc., and the average driver can easily see real world improvements about equal to swapping their car out for a hybrid version of the same model. I drive a Scion xA and routinely get 40 mpg, which is above the EPA rating for that model (when it was still in production). We certainly need to change the nouns and verbs in our lives (what we buy and what we do with it), but we also need to change the adjective and adverbs (how we do things).
    Response:

    [DB] I have found that I improved my gas mileage by 6 mpg by reducing my average speed from 5 mph above the speed limit (yes, I was one of the masses who routinely flouted the speed limits) to 1 mph under the speed limit.  Much better mileage and no chance of speeding tickets.  And lower blood pressure.

  35. Economic Growth and Climate Change Part 2 - Sustainable Growth - An Economic Oxymoron?
    skept.fr "That is particularly true for a fast transition – people and society are not so flexible." I'm not so sure about that. afaik, most people really don't care how their power is generated unless they have a job in a mine or a generation facility. For transmission infrastructure, some engineers might be stick-in-the-muds who'd like to keep doing what they've always done, but there are many who'd really like to see more efficient and effective distribution systems. Users rarely care about the details as long as the power stays on. As for industry. Just pick the low-hanging fruit to start with. If they can save money on airconditioning and lighting - esp for administration facilities which they see as a cost burden on their productive processes anyway - they'll get a taste for it. And then look for ways to do things better with their core operations. For transport. People who already use public transport will welcome any improvements in services. People whose access to such services is poor at the moment will adopt useful services if they are provided. The only issue is how quickly they'll do so. It's just a question of design and how much governments or other agencies are willing to spend at start up before the frequency and quality of the service gets a good enough reputation for more and more people to use it.
  36. Economic Growth and Climate Change Part 2 - Sustainable Growth - An Economic Oxymoron?
    perseus @41, yes pursuing a low or zero emissions economy with continued population and economic growth is a gamble. That is the invidious position we have been placed in by the slow response to global warming. But ending economic growth as a deliberate policy, or population growth in the short term are not political possibilities, and shackling the response to global warming to those policies just makes any effective response to global warming less likely. Further, there is no instance in history (that I know of) in which either declining population or declining economies have not caused wide spread suffering. Further, rapid technological change with static economies will cause wide spread suffering as already discussed. So your proposal is also a gamble, and IMO a far greater gamble than the alternative.
  37. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    skept.fr @53, no! What I suggest is that one of the model warming ratios, the land proxy temperatures, the sea proxy temperatures, or both, are in error because of the discrepancy between the Warming ratio found by Schmittner et al, and that from models in Sutton et al. I further suggest based on the additional evidence of warming seas north of Iceland according to Schmittner et al's reconstructions that an underestimate of sea surface temperatures is at least one component of the puzzle, so that once the issue is cleared by further studies a higher estimate of climate sensitivity is likely to be one of the results. Further, regarding models, the UVic model is described as follows:
    "A globally-averaged lapse rate is used to reduce the model’s apparent sea level temperature in calculating the following: the outgoing longwave radiation; the surface air temperature (SAT) dependent planetary co-albedo through the calculation of the areal fraction of terrestrial snow/ice; the saturation specific humidity to determine the amount of precipitation; whether the precipitation will fall as rain or snow"
    and:
    "The other major simplification to the atmosphere is the parametrization of atmospheric heat and moisture transport by diffusion, although moisture advection by the winds is also included as an option (Section 4)."
    Ray Pierrehumbert comments on this at Real Climate:
    "What is more severe, in my view, is that the energy balance model cannot represent the geographic distribution of lapse rate, relative humidity or clouds. In the interview over on Planet 3, Nathan Urban clearly doesn't understand the full limitations of the model even though he is one of the authors of the paper. It's more than just failing to represent the albedo effects of clouds -- the model doesn't represent the geographical variation of cloud infrared effects either, or the way these change with climate. Given that clouds are known to be the primary source of uncertainty in climate sensitivity, how much confidence can you place in a study based on a model that doesn't even attempt to simulate clouds?"
    So, this is not just another example of GCM's disagreeing about climate parameters. This is a case the model not allowing the relevant variables that determine the warming ratio to be set by physics within the model. That is a fair enough choice given budget constraints, but it does have consequences. Further, with regard to the use of other models, James Annan writes:
    "Jules has also been looking at some of these data recently, particularly in comparison to the PMIP2 experiments - that is, simulations of the last glacial maximum by several state of the art climate models, most of which also mostly contributed to the CMIP3/IPCC AR4 database of modern/future projections. One telling point is that several of the PMIP2 models actually appear to fit the data better than Schmittner's best model, even though these were not specifically tuned to fit the data. Moreoever, these models are all clearly colder, in terms of global mean temperature anomaly, than the -3C value obtained in this latest paper. We haven't done a thorough analysis of this yet but I think it is safe to say that there is a significant bias in the Schmittner fit and that the LGM was really more than 3 degrees colder than the present. The implication of this for climate sensitivity is not immediate (since there are also well-known forcing biases in the PMIP2 simulations), but this line of argument also seems to suggest that it may be reasonable to nudge the Schmittner et al values up a bit."
    So initial indications are that use of an ensemble of AOGCMs would have resulted in a higher climate sensitivity than found in the paper. So, I think in this case we can consider AOGCMs, and certainly and ensemble of AOGCM's to be more realistic in this case (because UVic ignores physics for relevant processes) and that it does make a difference, and is likely to have biased Schmittner et al's results low. Again, this is not a flaw in Schmittner et al's study, but a constraint on it. I'm sure they would have preferred to use an ensemble of AOGCM's if somebody had ponied up the cash. Nor is it a conclusive argument that they are wrong. But it is certainly grounds for caution with regards to their result, and suggests that when all the smoke clears, they will be low estimate of the LGM climate sensitivity.
  38. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    skept.fr @52, they allow change in albedo due to changes in ice sheet as a forcing in the model. Because the change is ice sheet is treated as a forcing, it is not treated as a feedback. Hence there are no (or at least no large) slow feedbacks in their model, from which it follows that they estimate fast-feedback climate sensitivity.
  39. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    Most importantly, I think the central point is not how well UVic model deals with evaporation, lapse rate, etc. – it is very unlikely in my mind that a particular model can be considered as more or less realist in its simulation, see here for example (figure 8.14) the still important divergences among IPCC AOGCM for WV, lapse rate, cloud, etc. The land/ocean warming ratio is a starting point from the reconstructed temperature (new proxy data set), not an utlimate result from the model runs. The model just try to reproduced the temperature and it seems to me that you reason as if the inverse was true. If the new proxy reconstruction is correct, then the land-ocean ratio will have to be reproduced by any model, no matter its complexity (RCM, EMIC, AOGCM, etc.). What you suggest in fact is that the proxy results are probably false, because most models produce a land/ocean warming ratio incompatible with the new proxy-based temperature.
  40. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    #51 Tom : "In contrast Schmittner et al discuss fast-feedback climate sensitivity" This point is not clear for me. Their analysis deal with "annual mean surface temperature (sea surface temperature over oceans and near surface air temperature over land) change between the LGM and modern" (legend, figure 1). So in my mind, that is a 10 or 12 ka change between two equilibrium states, including what you call "slow feed-back".
  41. Economic Growth and Climate Change Part 2 - Sustainable Growth - An Economic Oxymoron?
    If these models conclude that we can preserve economic growth while substituting fossil to non-fossil energy sources in the next 40 years, I think we must conservatively give credence to these models for their realism (that is, we should prove there are wrong if we disagree with their conclusions). I thought Jacksons calculations would have laid this possibility to rest. Let me repeat it again: In his book ‘Prosperity Without Growth’ Jackson calculates how much we would need to reduce the product of energy intensity and carbon intensity (in units of CO2e/economic output) to meet a CO2e of 450 ppm by 2050 without adjusting GDP or population growth rates. In the absence of such controls, we would need to reduce this factor by 10 times faster than the present rate, that is a 21 fold improvement by that date relative to the present to meet this target! Some other scenarios regarding population or GDP growth would require a virtual complete de-carbonisation of our entire energy system. Nothing other than a revolution in energy generation could meet 450ppm whilst retaining economic growth. That is the gamble people are taking who reject this. Is this too different to the mentality of those who reject climate change altogether? Are they not all either Deniers or gamblers?
  42. Economic Growth and Climate Change Part 2 - Sustainable Growth - An Economic Oxymoron?
    For orders of magnitude, fossil fuels produce approx 425 EJ or 13,5 TW each year. Solar radiation on land surface at the exclusion of polar, subpolar and difficult access regions produces a suitable flux of 15 PW, nearly a thousand times fossil consumption. For wind energy, the theoretical estimate of accessible flux is approx. 70-80 TW, five times the fossil flux. Waves kinetic total energy is 60 TW, but for coastal exploitation the value is rather 3 TW, a fourth of fossil flux. Tidal total energy amounts to 3 TW, but just 60 GW on coasts. Geothermal flux is estimated at 42 TW, but mainly on ocean floor so the current potential on land surface would be 100-600 GW. Terrestrial photosynthesis proceeds at a rate of 60 TW, from which approx 3 TW are currently exploited. So the conclusion is clear : the total amount of renewable energy flow that humanity could exploit is far over the fossil fuel, with direct solar energy as the most important source. Without even mentioning nuclear fission or fusion. But as we are speaking of economic growth (and climate mitigation), I think the relevant question is not the total and theoretical energy flow for a long term transition (numbers above), rather the realist exploitation of this flow on short term (decadal rather than centennal scale). We should recognise that either on energy density (amount of energy per unit of volume) or on power density (rate of flow of energy per unit of surface of land area), most renewable sources are for the moment less efficient that fossil or nuclear. And that’s also true for energy conversion from total incoming flux to final service, particularly for solar processes (the main source from total energy flux on Earth). As 80% of our energy come from fossil sources, the other problem is the weight of installed infrastructures in transportation, industry, building, etc. as they represent capital assets and human skills (ultimately, jobs). These points are much more uneasy to estimate and that’s why we must rely on energy-economy models. That is particularly true for a fast transition – people and society are not so flexible. If these models conclude that we can preserve economic growth while substituting fossil to non-fossil energy sources in the next 40 years, I think we must conservatively give credence to these models for their realism (that is, we should prove there are wrong if we disagree with their conclusions). But for sure, from all that I’ve read, a strong effort toward the use of clear and similar indicators among energy-economy models is needed (as this have been done in IPCC WG1 climate models). For the moment, each model ‘tinkers’ its own energy mix and cost estimations, but in the public debate, we need much more clarity about what we can and cannot choose, and at which cost. Ultimately, economic growth and climate change are particular points of a larger democratic debate. I remember here the Mike Hulme’s interesting essay, Why we disagree about climate change. We, citizens, have different and sometimes discordant attitudes toward nature, technology, risk, well-being, etc. These attitudes ultimately depends on our psychological traits, ideological convictions or ethical beliefs. What we can do here is to precise the basic facts, then to clarify our interpretations and to test their coherence, but I would say there is no reason (and probably no hope) to reach an ultimate consensus. That is particularly true for our most subjective judgments on capitalist or market-based societies. As a regular reader of 'degrowth' (negative growth) advocates, like for example Serge Latouche or Philippe Ariès for French authors, I observe that the frontier between growth as physically impossible trend and growth as ethically undesirable attitude is not very clear. As Tom put it in a previous message, a substantive judgement on growth is welcome as a starting point.
  43. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    skept.fr @50, Royer et al, 2007 has shown that climate sensitivity between 1.6 and 5.5 degrees C has been a feature of the Earth's climate for the last 540 million years. More recently, Park and Royer, 2011 refines that result. As they state in their abstract:
    "As a result, our experiment maintains an agreement with ΔT2x estimates based on numerical climate models and late Cenozoic paleoclimate. For a climate sensitivity ΔT2x that is uniform throughout the Phanerozoic, the most probable value is 3° to 4 °C. GEOCARBSULF fits the proxy-CO2 data equally well, and with far more parameter choices, if ΔT2x is amplified by at least a factor of two during the glacial intervals of the Paleozoic (260-340 Ma) and Cenozoic (0-40 Ma), relative to non-glacial intervals of Earth history. For glacial amplification of two, the empirical PDFs for glacial climate sensitivity predict ΔT2x(g)>2.0 °C with ∼99 percent probability, ΔT2x(g)>3.4 °C with ∼95 percent probability, and ΔT2x(g)>4.4 °C with ∼90 percent probability. The most probable values are ΔT2x(g) = 6° to 8 °C. This result supports the notion that the response of Earth's present-day surface temperature will be amplified by the millennial and longer-term waxing and waning of ice sheets."
    Note that they are discussing the slow-feedback climate sensitivity, ie, the climate sensitivity with the Earth is allowed to adjust by changes of vegetation, and the melting of ice sheets etc. In contrast Schmittner et al discuss fast-feedback climate sensitivity. For comparison, Hansen has recently found a fast-feedback climate sensitivity of 2.8 degrees C per doubling, and a slow feedback climate sensitivity of 6 degrees C per doubling of CO2. Applying the same ratio to Schmittner et al' fast-feedback climate sensitivity from their best fitting model (2.4 degrees C per doubling of CO2) would yield a slow-feedback climate sensitivity of 5.14 degrees C per doubling. Most of the response of the slow-feedback climate sensitivity is due to melting ice sheets, so that in non-glacial worlds the slow and fast feedback sensitivities approximately equal each other (best estimate 3 to 4 degrees C ). Applying Hansen's ratio to the glacial slow-feedback sensitivity suggests a glacial fast-feedback as derived from Park and Royer in the range of 2.8 to 3.7 degrees C. That is a little rough, of course, but suggests that slow-feedback climate sensitivities are approximately constant across a wide range of geographical configurations and temperature ranges. To that it should be added that in discussing Schmittner et al, Real Climate report that Hargreaves and Annan find model simulations of the LGM show short-feedback climate sensitivity that is 80-90% of that found for a doubling of CO2 from preindustrial conditions across a range of models. So, some difference, but small. More importantly, and as discussed in my post @48, because the equilibrium warming ratio is a consequence of evaporation, either directly, or due to increased humidity and hence reduced lapse rates, in a cooler world (and hence a world with less evaporation) we would expect the warming ratio to be smaller. Indeed, there is some evidence of this in Sutton et al, 2007 which show the warming ration declining to 1 near the poles in models, and (less clearly) in observations. Hence, while I do think there will be some change in the Warming ratio in the LGM, it will be in a direction that makes my point (1) above more significant, and my point (2) above less significant.
  44. Peter Hadfield addresses the recent email release
    Yes, I love how he once again highlights how so-called "skeptics" will swallow every piece of nonsense they read on the internet *without* bothering to double-check the validity of the claims-the exact *opposite* of a genuine skeptic.
  45. Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
    #48 Tom : on Real Climate, I read : The first thing that must be recognized regarding all studies of this type is that it is unclear to what extent behavior in the LGM is a reliable guide to how much it will warm when CO2 is increased from its pre-industrial value. The LGM was a very different world than the present, involving considerable expansions of sea ice, massive Northern Hemisphere land ice sheets, geographically inhomogeneous dust radiative forcing, and a different ocean circulation. The relative contributions of the various feedbacks that make up climate sensitivity need not be the same going back to the LGM as in a world warming relative to the pre-industrial climate. Sutton et al 2007 examined what the IPCC AR4 models give for land/ocean equilibrium change from our current temperate climate, not from glacial initial conditions. So I think their land/ocean ratio must not necessarily be used as a robust benchmark for LGM/Holocene transition. In other word, it is suggested (in the RC quote) that climate sensitivity for a doubling C02 (as well as local/global signatures of this doubling) should not be seen as a constant for the different climates of our planet over time.
  46. We're coming out of the Little Ice Age
    Stefaan, I understand your point but as I understand it, the argument regarding the LIA is more like "there is a normal temperature given the environment - there was an exceptionnal reason to change it - the reason is gone - therefore it goes back to the normal temperature". which doesn't seems so wrong in theory. Still I am no scientist. Nevertheless you don't always need to be one to take good decisions. I know that a man can die if he stays in a confined environnement with a car's engine on. It sufficient for me to believe that it's not a good idea to have millions of cars on earth without evidence of the absence of effect.
  47. Climate Solutions by Daniel Bailey
    There are more significant changes that can be made culturally and in legislation. 1. Build infrastructure that puts businesses closer to homes. Build communities where it is natural to walk and cycle etc. and the car is not seen as being essential. 2. Legislate for all new homes to be built to use the minimum amount of energy. This would depend on the location globally, but passive home design is a proven idea that works.
  48. Climate Solutions by Daniel Bailey
    uuurgh don't like vinyl windows. There is a Scandanavian company that makes soft wood/aluminium combo triple glazed windows which would be my preference. Not that it would make any difference in the UK, where many old houses are abused with fitted plastic windows and other plastic building materials.
  49. Antarctica is gaining ice
    Is there a possibility that the earth's axis has moved marginally i.e the North Pole is now slighty closer to the sun thus warmer there but colder in the south creating more ice in the Antartic. Wouldn't this also explain the changes in the magnetic fields that some scientists have apparenty noticed? i do believe that the recent earthquakes in Japan were strong enough to move the axis of the Earth albeit a small amount.
    Moderator Response:

    [DB] If you think about this you'll be able to answer your own question.  Any astronomer in the world can tell you that there's no evidence whatsoever for it.  GPS systems would be way off.  The tides would be different.  Satellites that measure earth changes to sub-millimeter accuracy would also provide evidence against it.  There is simply no physical evidence to cause such a shift that would not also be felt the world over.

    The crustal displacement/polar wander fancies of Hapgood are just that: flights of imagination.

  50. Peter Hadfield addresses the recent email release
    Oh, how I wish I could get my local State MP to watch this video. She is a perfectly nice person who is, for some reason, a rabid denier - not a sceptic, sadly, or I would send her the link in hope that she would watch it. A great video and I thank you for putting it up here. I, too, have not read the original emails, so it is nice to now have some context.

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