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Comments 79651 to 79700:

79651. actually thoughtful at 03:47 AM on 12 July 2011
       Climate Solutions by Rob Painting
       John Russell - awesome list. Where do you live? _________________________ In the discussion so far regarding personal vs political, I haven't seen any explicit statement that we all are, personally, political. When elections roll around and a politician puts forward a pro-PV plan; my neighbor the extreme right winger (with the PV panels) is going to be able to give the politician a serious look - afterall - PV CAN'T be crazy if my right wing neighbor ALREADY has it, right? Personal action changes each of us, in small to large ways (I think John Russell and Ranyl said as much in their posts of relatively major changes in how the power their lives). Change people = a changed electorate. Which changes policies. I would enjoy living in a world where rational policies are chosen for rational reasons. But I am stuck on this one. The strategy of "do the science and policy makers will grasp the severity of the situation and act pro-actively to save humanity from the very dire outcomes currently anticipated" has FAILED. It is not happening (I am somewhat US centric, but the US is still the worst offender on a per capita basis, so it is hopefully an OK centricsm). What is the next plan? Gorilla action. Because personal action also changes those around you. A rudimentary understanding of the Operating System of humanity is necessary here - we are sheeple. We DO look to see what so-and-so is doing. The strategy is to dramatically increase the percentage of so-and-sos who have taken action (preferably visible action that you brag about endlessly). As near as I can tell, this is the best/fastest path to changing the current ruinous path that we are on. Also, there is much talk about achieving grid parity for PV and wind. And it is well known that PV efficiency increases as a function of installed capacity (not that the installation increases the efficiency mind you). So those that are taking action now are literally priming the pump for the zero carbon economy (and it is necessary to overcome the chorus of naysayers (some of whom are relatively well-meaning)). Sheeple - its not a bug, its a feature.
79652. BobC at 03:38 AM on 12 July 2011
       CO2 has a short residence time
       The theoretical estimation of adjustment time (vs. residence time) is being done by measuring or estimating the various rates in the carbon cycle box models. The derived growth rates are quite small, compared to the measured (or estimated) flows into and out of many of the boxes. This means that the derived adjustment time depends on accurately knowing a small difference between large numbers. As a result, the adjustment (or relaxation) time is known (from box models) with a much greater uncertainty than the larger flows are known. It is easy to do some numerical experiments with a calculator to convince yourself of this, if you haven't already been exposed to it via measurement statistics. A much better solution is to actually measure the relaxation time of CO2 in the atmosphere. Conveniently, this has been done by several of the peer-reviewed studies in the [snip] link given by poster #1, Tom Dayton. The studies I’m referring to used radioactive carbon-14 as a tracer. Prior to WWII, C14 was essentially in equilibrium with C12 in the environment, in all those ‘boxes’ that have significant in and out flows. (This is why carbon14 dating works – when something dies, the exchange stops and the C14 slowly decays radioactively with a 5000 year half life. The resulting drop in C14 concentration is therefore an indication of the date of death.) Between 1945 and 1964, the human race injected a relatively large amount of C14 into the atmosphere via the atmospheric explosion of atomic bombs. The Atmospheric Test Ban treaty of 1964 put an abrupt stop to this injection. The decay of atmospheric C14 concentration since then is a direct measurement of the relaxation (e.g., adjustment) time for CO2 in the atmosphere. (Since most bomb tests were in the Northern Hemisphere, it also gives us a measurement of the mixing time between hemispheres -- about 2-3 years.) The results, which can be seen on Wikipedia’s Carbon-14 page, is that the CO2 adjustment time in the atmosphere is ~10-12 years (stated as a half-life). Compare the plot shown on this page with the theoretical plots (from box models) posted by Dikran Marsupial @ 93. If you want to dispute this, you shouldn’t argue with me about it, but rather the thousands of scientists and engineers (and published papers) that use the well known and tested method of tracer measurement. (Google "tracer" and "measurement" for a huge list -- start anywhere you like.)
       Moderator Response: [Dikran Marsupial] minor edit (as discussed with author)
79653. Albatross at 03:34 AM on 12 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Norman @313, Regarding the myths--well myth may be too strong a word, perhaps misconception is more appropriate. You say "Ice is not deposited on hailstones to make them grow." While hail growth from the accretion (interception) of supercooled droplets is very important, the hail growth equations also allow for the growth of hail by intercepting ice crystals. This is especially effective during wet growth when collection efficiencies of ice onto the wet surface is quite high, but is less effective during dry growth when the collection efficiency for ice is very low. Anyhow, the first common misconception that I was referring to are that hailstones grow to large sized by "clumping together". While this may happen on rare occasions, it is certainly not the norm. This misunderstanding probably arises because of images like this (of the largest hailstone on record in the USA): Those nodes/knobs can be simulated without having to allow for hailstones "clumping together" (e.g., Lozowski et al. 1991"). They can also form when a gyrating hailstone undergoes melting (e.g., Lesins and List 1986) . The second misconception that I was referring to was that the layer son a hailstone form because the stone grows by undertaking repeated cycling through the updraft. Research has shown that this, while again is certainly possible, is not the norm. According to a meta analysis of Knight and Knight (2001)[Chpt. 6 in "Severe Convective Storms"]: "The trajectories themselves, however, are usually quite simple, given embryos to start with: single, up-and-down paths though and around the main updraft. Recycling paths are found, but not very often, and when recycling trajectories are found the decision of what part belongs to the embryo stage can be quite arbitrary" And "...they [hailstone layers] do not carry a message of drastic, repeated vertical excursions, but if anything the opposite: of relatively simple growth trajectories, often with most of the growth within a fairly narrow altitude and temperature ranges.
79654. BBD at 03:14 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       CBDunkerson "PS: 200 * 20% = 40. Not 20. " Whoops. Thank you.
79655. CBDunkerson at 02:58 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       Two different surface insolation values are being cited in the 'discussion' above. The 'correct' values are: 1000 W/m^2 is the global average insolation under full sunlight 250 W/m^2 is the global average 24 hour insolation... including morning, afternoon, night, cloud cover, et cetera. Thus, a 20% efficient panel would indeed generate an average of about 200 W/m^2 (more nearer the equator / less nearer the poles)... when the Sun was shining. The lower values (50 W/m^2 in this case) come from averaging that power generation over a 24 hour day... even night, when the generation is obviously near 0%. PS: 200 * 20% = 40. Not 20.
79656. BBD at 02:49 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       Tom I appeal for clarity and reason:

       So, and most emphatically, the 0.2 KW was not simply drawn from nowhere. It was calculated by multiplying the expected insolation by an efficiency factor. You may want to argue that 20% efficiency is to high, but it is not 100% efficiency. LAGI do not use a 200 Watt insolation value (which they give as 1000 W/m^2), and they do not omitting the panel conversion efficiency (which they give as 20%).

       - Of course the 200W/m2 (0.2kW/m2) was not 'drawn from nowhere'. I have repeatedly said that it is a fair estimate for average surface insolation for low latitude desert locations. - Here (again) is a table which shows why I would say this. Look at the values for average sunshine in W/m2. - Now, please show me where LAGI uses the necessary additional technology conversion factor - At the same time it will be trivial to show me that LAGI did not use 200W/m2 as the basis for the rest of its calculation, which would of course invalidate its estimate No more insulting language, no more straying away to other matters. I want your point-for-point response to this with full workings for any additional calculations you use.
79657. Tom Curtis at 02:46 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       BBD @257: From LAGI:

       "Using 70% as the average sunshine days per year (large parts of the world like upper Africa and the Arabian peninsula see 90-95% – so this number is more than fair), we can say that there will be 250 sun days per year at 8 hours of daylight on average. That’s 2,000 hours per year of direct sunlight."

       2000 hours times 1000 Watts/m^2 equals 2,000,000 * 60 * 60 = 7.2 billion Joules/m^2 per annum of insolation. 7.2 billion Joules over one year = 7,200,000,000 / (365.25 * 24 * 60 * 60) = 228 W/m^2 averaged over the year. So LAGI plainly take into account the average rate of insolation, but they do so by direct calculation rather than taking an initially averaged value for insolation. Of course, we already knew this because we had a direct comparison between the LAGI figures for insolation and those for Andasol from 247 above:

       "4) LAGI quote a thousand Watts of direct sunlight for 2,000 hours (23%) of the year for a total of 2,000 kWh/m^2 of direct sunlight per annum. For comparison, the Andersol plants experience per annum from 2,136 kWh/m^2 per annum in the south of Spain, so again the LAGI figures are conservative with areas in North Africa likely to experience much more both because of higher solar intensity and fewer cloud days."

       That's right, LAGI's figures for direct insolation are 6% less than those achieved at Andasol in the South of Spain, even though many of the LAGI sites are located in regions achieving 16% or more greater annual insolation than the south of Spain. Of course, when I say "we knew this" I am excluding those who are unable to comprehend more than one paragraph at a time of a viewpoint they disagree with, and who continuously quote out of context to try and give substance to arguments that are, in the end nothing but dogmatism. ( -Snip- )
       Response:

       [DB] Everyone, please take a deep breath and try to keep the emotions out of the discussion.  I know that's hard, as that's why I moderate instead of engaging as participant (I often end up deleting my own comments on those occasions I get caught into a discussion). 

       Letting others knock us off our "A" game only detracts from the quality of the dialogue.

79658. muoncounter at 02:30 AM on 12 July 2011
       Trenberth on Tracking Earth’s energy: A key to climate variability and change
       #2 Kevin C: "I presume the difference is either a change in albedo and/or a reduction in OLR." Why do you presume? If there is evidence for either, what is it?
79659. BBD at 02:25 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       KR ( -Snip-):

       Now - taking a look at PV power plants, which can attain fill factors approaching 100%, we're looking at 150 W/m^2 for a 15% efficient PV system. So - your 15 W/m^2 is low to start with, by almost an order of magnitude.

       If surface insolation at the site is 200W/m2, and we use the 20% efficiency you claim for Andasol (which I do not necessarily accept btw), we get 20W/m2 Please explain here, with your workings shown, how you get from a 200W/m2 insolation (or 150W/m2 if you prefer) to an efficiency of '150W/m2' applying a 15% conversion efficiency. I'm struggling to remain polite now. I will say this: you appear to have become confused between packing factor and conversion efficiency. It sounds to me as if you don't really understand what is being discussed here.
       Response:

       [DB] As CBD has pointed out, 200W/m2*(0.20)=40W/m2.

       Before complaining about the splinters in other's maths, one would do well to first remove the planks in one's own.  In maths and rhetoric.

       Everyone, please focus on keeping civility in this discussion.  The moderation level has just been toggled up a notch.

79660. Kevin C at 02:15 AM on 12 July 2011
       Trenberth on Tracking Earth’s energy: A key to climate variability and change
       Very helpful article. You show the net radiation increasing significantly after 2005. This is based on satellite measurements, right? What is changing? The increase seems to early to me to be solar cycle 24, so I presume the difference is either a change in albedo and/or a reduction in OLR. Are there numbers for each of these? Are they in accord with changes in e.g. atmospheric composition? Thanks!
79661. Byron Smith at 02:12 AM on 12 July 2011
       OA not OK part 4: The f-word: pH
       Thanks Doug. :-) Seriously, I really do appreciate this series. I have little to offer on the conceptual science, as my own formal chemistry education ceased when I was 18, but had actually been looking for a more in-depth explanation of ocean acidification to offer on the countless threads with chemistry-illiterate (and yet predictably vociferous) deniers.
79662. BBD at 02:08 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       Tom You just do not see it yet. Look at the average sunshine in W/m2. 200W/m2 is a fair estimate for average ground level insolation in a low latitude arid/semi-arid location. Let's say we apply a 20% technology conversion efficiency to this. We get 20W/m2. This is obvious and elementary reasoning. But LAGI uses the whole 200W/m2. There is no conversion efficiency step. I literally cannot understand why you don't see this. It's trivial. This is why LAGI comes up with a nonsense result of 500,000 km2 = 23TW and MacKay (and other numerates) come up with 1,500,000 km2 = 23TW. When are you going to concede that you've got this wrong? LAGI is missing a vital step and I have shown you exactly where it happens.
79663. Peter Peete at 01:39 AM on 12 July 2011
       Venus doesn't have a runaway greenhouse effect
       Hello, this a really nice article, I want to give a thanks for it.
79664. Humanracesurvival at 01:38 AM on 12 July 2011
       Trenberth on Tracking Earth’s energy: A key to climate variability and change
       Great article, i will study the details in the coming days! Here a topic i currently working on... Pedology – Erosion & Weathering during the PETM In 1998 Karl and Knight reported that from 1910 to 1996 total precipitation over the contiguous U.S. increased, and that 53% of the increase came from the upper 10% of precipitation events (the most intense precipitation). The percent of precipitation coming from days of precipitation in excess of 50 mm has also increased significantly. Studies by Pruski and Nearing indicated that, other factors such as land use not considered, we can expect approximately a 1.7% change in soil erosion for each 1% change in total precipitation under climate change. The removal by erosion of large amounts of rock from a particular region, and its deposition elsewhere, can result in a lightening of the load on the lower crust and mantle. This can cause tectonic or isostatic uplift in the region. Research undertaken since the early 1990s suggests that the spatial distribution of erosion at the surface of an orogen can exert a key influence on its growth and its final internal structure (see erosion and tectonics).
       Moderator Response: [muoncounter] Hot-linked; however, this has nothing to do with the topic of this thread. Please stay on topic.
79665. BBD at 01:34 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       Tom You are going to have to stop doing this sort of thing and re-engage, with a clear head:

       Ignoring the irrelevance given that LAGI calculate an area of approx 500,000 km^2, not 10,000 km^2 (100*100), we now know that when Mackay writes "allowing no space for anything else" he actually means "using just one quarter of that space for the solar field". We also know that he arbitrarily and with no justification given excludes any possibility of dual land use, at least in that calculation. (At another point in the book he points out that wind and solar power can occupy the same land footprint with very little loss of efficiency for either, then brushes it of. Clearly offshore wind and wave power can also take advantage of shared location with no efficiency loss in generation, and efficiency gains for transmission.)

       - What 'irrelevance'? It's an argument about scale and capacity. You are trying to delegitimise MacKay - When MacKay writes 'allowing no space for anything else' that's exactly what he means. Go back, and read it again. Where on earth do you get 'using just one quarter of that space for the solar field'? Seriously? Where? (See below before replying) - We are discussing the incorrect LAGI claim that 500,000 km2 of solar plant (with no spacing; 100% packing factor is assumed) can generate 23TW - But anyway, hot deserts are not windy enough for efficient wind generation The rest is a descent into further irrelevance. Until we get to this:

       However, I do admit that my 232 was in error, partly because I did not note Mackay's mistaken figure of 1/3rd land used when he meant 1/2, but mostly because I made an error due to tiredness (at 3:41 am).

       Your 232 is wrong because using MacKay's numbers you need ca 1,500,000 km2 to generate 23TW. That's because his calculation includes a conversion efficiency step and works from 15W/m2. Unlike LAGI, which mistakenly omits this step and runs on 200W/m2. Which is how it gets a seriously wrong result. MacKay is working with 100% coverage - the irrelevance of the erratum on p181 is irrelevant. You misunderstand this because you haven't read the caption. Do so now. See the numbers: 65 x 1500 km2 areas of 50% plant footprint, 10GW generation per area. Which yield just 16kWh/d/p for 1bn people. As compared to the 125kWh/d/p average European usage. Not only is this result consistent with MacKay's 100% coverage estimate, it is further confirmation of the scale of the error in LAGI. Errors happen. Nobody minds. It is willful refusal to acknowledge the exact nature of an error that is a problem.
79666. KR at 01:32 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       BBD - "MacKay uses 15W/m2 energy density for desert sited CSP" That's low even by CSP standards - the Spanish AndaSol facility will have (due to only a small percentage of fill area) a gross efficiency of 2.6%, or >20 W/m^2. CSP has a conversion efficiency of 18-30% of collection area, depending on design, with some of the linear trough and Fresnel layouts having considerably higher fill factors than basic tower geometries. Fully filled a CSP would have a 200 W/m^2 output, although I don't expect that to get over ~100 given current designs. They do seem to be less expensive to build than PV systems on a per/Watt basis, though, and thermal storage is very attractive. Now - taking a look at PV power plants, which can attain fill factors approaching 100%, we're looking at 150 W/m^2 for a 15% efficient PV system. So - your 15 W/m^2 is low to start with, by almost an order of magnitude.
79667. Alec Cowan at 01:22 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       Tom, why you bother? It looks to me like just some game of power is played here, with (non)-renewable energies as the party theme. Be sure of not being driven where you don't want to be. You can't address the arguments of an innumerate using his own 10, 15, 20, 30, 50 and 70s and multiplying or dividing by 2 like they do. Get your figures reusable. Never do them just for these creatures: they don't want them, they don't allow them, and most importantly, they can't understand them as independent of wishing conclusions generated in advance. Also, let them to abuse of adjectives and other 'rhetoricalities'. Moderators: Please, consider if it is not time of flushing a lot of comments that are just spam.
79668. Esop at 01:02 AM on 12 July 2011
       SkS Weekly Digest #6
       Check out UAH channel 5: http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps Lower troposphere temperatures just matched the record (for the date) set in 2010. This despite us coming out of a major La Nina. I thought we were headed for a GCR induced Svensmark Ice Age. Didn't he claim that global warming stopped in 2009? Looks like he was wrong and James Hansen right about 2012 as the next record year. What a surprise.
79669. Tom Curtis at 01:00 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       BBD @244 (again): 1) The efficiency is unitless. It is kW/m^2 of electricity produced divided by kW/m^2 of insolation. 2) LAGI write:

       We can figure a capacity of .2KW per SM of land (an efficiency of 20% of the 1000 watts that strikes the surface in each SM of land). So now we know the capacity of each square meter and what our goal is. We have our capacity in KW so in order to figure out how much area we’ll need, we have to multiply it by the number of hours that we can expect each of those square meters of photovoltaic panel to be outputting the .2KW capacity (kilowatts x hours = kW•h)."

       (my emphasis. Bolded section is the context BBD elided in his quotation.) So, and most emphatically, the 0.2 KW was not simply drawn from nowhere. It was calculated by multiplying the expected insolation by an efficiency factor. You may want to argue that 20% efficiency is to high, but it is not 100% efficiency. LAGI do not use a 200 Watt insolation value (which they give as 1000 W/m^2), and they do not omitting the panel conversion efficiency (which they give as 20%). What is more, LAGI explicitly stated this. Indeed, they did so in the sentence immediately before the paragraph you chose to quote. To quote, in fact, in order to prove that they used an insolation value one fifth of that which they had just stated they had used, and that they did not use the efficiency factor they explicitly stated they used. In my world, what you have done is called "quotation out of context" and your example ranks well up their with some of the more egregious examples I have seen from creationists. Now I will once give you the benefit of the doubt and simply assume that you are not practised in reading for comprehension. But you had better come down of your high horse and pretence that we are not reading your words of wisdom when you are plainly not reading our simple statements of fact.
79670. BBD at 00:55 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       More good grief:

       3) LAGI quotes a 20% efficiency of collection. For comparison , the Andasol 1, 2 and 3 plants have a 28% peak efficiency and an annual average of 15%, so 20% is reasonable.

       The words 'annual average' mean 'annual average'. So an 'annual average' of 15% is and annual average of 15%. Not 20% or half a green cheese. This is not the stuff of rational debate.
79671. Alec Cowan at 00:52 AM on 12 July 2011
       The Medieval Warm(ish) Period In Pictures
       @#15 Rob, why somebody would analyse "the Medieval Warming Period" and "the Litle Ice Age" if not for comparison with actual developments? If the adjectives "Western European" or "Northern Atlantic" were added, that would be a horse of a different colour. Why a warming period in human history has no paired higher global temperature to show? So, there must be some preconceptions the researchers are trying to address, for instance, that the actual warming period can't be compared with the so-called MWP. Then, baselines are important, otherwise, why they use anomalies instead of instrumental temperatures? If we have to be sensitive to change, be sure we are sensitized using a proper base. In a post that is addressing general publics that is no minor an issue. On the other hands, when a thing is an important subject for analysis and not a bit of a stretch, one should easily find other works with other base temperatures. Summarizing: MWP, LIA and actual AGW could be "easily" shown in contrast against a "normal" base, showing some misleading local warming and cooling for the first two what has clearly nothing to do with actual developments. Don't we have it? Well, such things happen when one allows [-snipped inflammatory comment] to dictate one's syllabus.
79672. Eric the Red at 00:52 AM on 12 July 2011
       The Medieval Warm(ish) Period In Pictures
       True, Am I misreading Figure 1. It looks as if Mann was saying that the two Russian areas were cooling by 1+C rather than warmer by 1+C. If Mann is stating that they were warming, then I agree. Sphaerica, Some evidence, in addition to those precedented in my previous post, showing a global MWP. http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/CookPalmer.pdf http://www.clas.ufl.edu/users/rrusso/gly6932/Oppo_etal_Nature09.pdf http://www.leif.org/EOS/2009JD012603.pdf
79673. BBD at 00:51 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       Tom MacKay is Mr Renewables. He's a big fan. Why would he do this?

       It is a rather underhanded way to deflate the actual efficiencies of solar plants.

       Why? He's also a professor of physics at Cambridge. And the chief scientific advisor to the UK Department of Energy and Climate Change (DECC). But, yes, of course he's talking through his hat and you are entirely correct. Go back, and read #236 and #244 again. Carefully. And read Mackay's chapter 25 thoroughly including end notes. Your work here is sloppy.
79674. BBD at 00:44 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       Tom I'm getting fed up with this:

       2) Mackay also quotes an average annual capacity of 15 Watts/m^2 for concentrated solar in North African deserts. You have provided no explanation for this discrepancy.

       See #244, third from last paragraph. Follow the link at "it doesn't matter if it's CSP or SVP". Read, and inwardly digest.

       3) LAGI quotes a 20% efficiency of collection. For comparison , the Andasol 1, 2 and 3 plants have a 28% peak efficiency and an annual average of 15%, so 20% is reasonable.

       How do you do it? How can you read a crystal-clear explanation of how LAGI gets it wrong and still come back with this? It is clear that you are not reading my comments. You have one of the most relentlessly closed minds I have encountered for a while. You need to open up a bit. you will not take me in with a shell game.. Good grief. The only person deceiving you is yourself. Stop muddling. Start thinking. Go back and read #236 and #244. It's all there.
79675. Tom Curtis at 00:39 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       BBD @244, quotes Mackay as saying:

       ""All the world’s power could be provided by a square 100 km by 100 km in the Sahara.” Is this true? Concentrating solar power in deserts delivers an average power per unit land area of roughly 15 W/m2. So, allowing no space for anything else in such a square, the power delivered would be 150 GW. This is not the same as current world power consumption. It’s not even near current world electricity consumption, which is 2000 GW. "

       (my emphasis) Ignoring the irrelevance given that LAGI calculate an area of approx 500,000 km^2, not 10,000 km^2 (100*100), we now know that when Mackay writes "allowing no space for anything else" he actually means "using just one quarter of that space for the solar field". We also know that he arbitrarily and with no justification given excludes any possibility of dual land use, at least in that calculation. (At another point in the book he points out that wind and solar power can occupy the same land footprint with very little loss of efficiency for either, then brushes it of. Clearly offshore wind and wave power can also take advantage of shared location with no efficiency loss in generation, and efficiency gains for transmission.) However, I do admit that my 232 was in error, partly because I did not note Mackay's mistaken figure of 1/3rd land used when he meant 1/2, but mostly because I made an error due to tiredness (at 3:41 am).
79676. Tom Curtis at 00:23 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       BBD, KR and I have both read 236. What is more, I adressed your arguments in 236 directly and found them to be without foundation. Disagreeing with you is not the same thing as not having read your comments or understood them. If anything, it is rather the opposite, a sign of both having read and understood what you say. To review: 1) Mackay quotes an average annual insolation rate in England of 100 Watts/m^2 after allowing for the effects of latitude and weather. A 15% efficient collector in England will therefore collect 15 Watts/m^2 even if laid flat on the ground. 2) Mackay also quotes an average annual capacity of 15 Watts/m^2 for concentrated solar in North African deserts. You have provided no explanation for this discrepancy. 3) LAGI quotes a 20% efficiency of collection. For comparison , the Andasol 1, 2 and 3 plants have a 28% peak efficiency and an annual average of 15%, so 20% is reasonable. 4) LAGI quote a thousand Watts of direct sunlight for 2,000 hours (23%) of the year for a total of 2,000 kWh/m^2 of direct sunlight per annum. For comparison, the Andersol plants experience per annum from 2,136 kWh/m^2 per annum in the south of Spain, so again the LAGI figures are conservative with areas in North Africa likely to experience much more both because of higher solar intensity and fewer cloud days. 5) From this LAGI calculate an electricity production of 400 kWh/m^2 per annum. For comparison, the Andasol plants achieve 350 kWh/m^2 per annum, so again the LAGI calculated value is reasonable. Indeed, with much of North Africa experiencing 17% more annual insolation than the south of Spain, that alone would lift an Andasol style plant in North Africa to 400kWh/m^2. I have to admit to being perplexed by Mackay's insistence on using a power generation factor of 15 W/m^2 in desert, until I stumbled on his description of the efficiency of the Andasol plant, which he gives as 10 W/m^2. In fact the Andersol plants achieve 41 W/m^2 of solar field averaged over the year, four times the amount Mackay quotes. The reason is evident, the solar field of the Andersol plants occupy just one quarter the site area. Mackay is calculating the efficiency relative to the site area rather than to the solar field. It is a rather underhanded way to deflate the actual efficiencies of solar plants. It is underhanded because, unlike in the south of England, in the south of Spain, and certainly in North Africa, the cost of land is so little as to be an almost negligible component of the overall cost. If it were not, it would be trivially easy to inflate the efficiency of power production per unit site area at a cost to the efficiency of power production per unit of solar field area. One obvious mechanism is to have adjacent troughs, with every second trough going to a neutral, non-shadow generating position when the sun is low in the sky, thus making the solar field almost equal in area to the site area most of the day, while halving efficiency relative to solar field area for a few hours on either side of dawn and dusk. Another method would be to have a continuous field of fixed shallow parabolic troughs with the collector moved during the day to remain in the focal point. In fact, if land area (rather than solar field area) where a real concern, it would probably be better to space the troughs further apart to allow more sunlight to the ground. The area between and under the troughs could then be used to grow fast growing grasses either for pasture or biofuel, thus gaining dual use of the land. None of these measures is considered worthwhile for the simple reason that the land itself is too small a cost to make such measures worthwhile. Mackay, in other words, is inflating a trivial cost as an artificial impediment to solar power. So, I'm happy to dump all preconceptions and start with an open mind, but you will not take me in with a shell game.
79677. Rob Honeycutt at 00:21 AM on 12 July 2011
       The Medieval Warm(ish) Period In Pictures
       Sphaerica... Spot on. In fact, the whole challenge of the MWP is getting an accurate read on what the actual global temperature was then, rather than just local temps. What climate deniers continually do is locate the one (or a few) proxies that support their position and claim that everything beyond that is a big conspiracy without ever bothering to look at the full body of evidence.
79678. Eric (skeptic) at 00:18 AM on 12 July 2011
       The Medieval Warm(ish) Period In Pictures
       I can imagine one source for warming in the MWP: a small forcing and a high sensitivity. I can also imagine that sensitivity is not a constant, in fact I propose that in various threads e.g. and never get an answer except "weather won't save us". It may well be that weather won't save us and that amplification of CO2 will be high. But that doesn't mean that weather didn't help cook the MWP.
       Moderator Response: (DB) You again make unsupported assertions (both here and on the other threads you reference) that fly in the face of known physics; that type of statement is referred to as "climastrology" and may fly in endeavors such as automotive research in the US, but is simply not credible in a climate science forum.
79679. Rob Honeycutt at 00:14 AM on 12 July 2011
       The Medieval Warm(ish) Period In Pictures
       Alec... I'm not sure why you're stuck on baseline periods. Pick a baseline of your own, it doesn't really matter. Choose a random baseline period if you like, it doesn't change the result of any of the data. The only thing a baseline period does is establish a zero axis.
79680. Alec Cowan at 00:00 AM on 12 July 2011
       A Detailed Look at Renewable Baseload Energy
       @BBD #236 How do you get all your numbers so round, even in your errata? It sounds pretty much like 100 scientist found 1000 reasons for temperature not raising 1 degree (Celsius/Kelvin, Fahrenheit, Réaumur, who cares?) in the next 100 years. With such figures, does anyone need to point what is wrong? I think not. 30 Helens would agree.
79681. Bob Lacatena at 23:49 PM on 11 July 2011
       The Medieval Warm(ish) Period In Pictures
       11, Eric the Red,

       The MWP has been acknowledged as the last period of globally warm temperatures (not just NH as claimed above).

       Completely untrue. Citation, please.

       The global temperature anomalies are similar to today...

       Untrue. Citation please. It was not as warm, and temperatures in many, many areas were cooler. The warming was far from global, or equally distributed in either space or time. Hence, your statement is only remotely close to true if you use a running 200 year average to compute temperatures, and even then temperatures were still markedly lower than those of the last ten years in particular.

       Whether that period was warmer than today is still open to debate...

       Not remotely true. Look at the literature instead of just making stuff up.

       In order to show that today's warming is unprecedented...

       There is no need to show that today's warming is unprecedented. That it will inevitably be unprecedented, whether or not it is now, is the second important point, but the main point is that the cause of today's warming is unprecedented. It is being caused by the understandable and predicted effect of CO₂, and it will be close to irreversible in human time frames if we take things too far. What is most entertaining about you, of all people, clinging to the MWP as yet another excuse to deny the physics behind climate science is the fact that there is no known or imaginable major source for warming in the MWP. This implies that such a cause was relatively small. This in turn points to a very, very high climate sensitivity as opposed to the foolishly low values to which you are so dearly wedded. That is the only way that the MWP could have been "as warm as today." If you believe in the MWP, then you must refute your need to cling to climate sensitivity predictions below 3˚C per doubling.
79682. Alec Cowan at 23:33 PM on 11 July 2011
       The Medieval Warm(ish) Period In Pictures
       @#10 Rob, I'm downloading the article by Mann, Zhang, Rutherford et al, and the supporting online material and I'm finding -correct me if I'm wrong- that a few proxies were used, that grey masks indicates regions were 1961-1990 data is insufficient to draw climatic normals -not insufficient proxy data, what didn't mean there were aplenty-, regions without hatching didn't pass validation, and the whole set was got using computer modeling. I suppose that when I read and analyze the article and dataset -at the best of my capacity- I'll be able to find what role played the proxies other than getting low-frequency components of the signals to reconstruct. I know it's nice to look at a world map and confirm happy Vikings in Iceland and Greenland and turbulent Mongols and Tartars in the seek of better pastures. It looks like reassurance. It's not so nice that the reconstruction for the Little Ice Age in the same work is showing also not cooling Iceland and southern Greenland. In my opinion variability in times of slow changing technologies is what makes your living impossible. Then, what's the use of a 12-generation anomaly? What I've seen so far makes me think that not much more imprecision would have come from using 1941-1970 normals. What would have let us comparing MCA, LIA and nowadays AGW. There'll always be the layman approach to the driven conclusions. That shouldn't drive anybody to choose inappropriate base periods.
79683. Trueofvoice at 22:46 PM on 11 July 2011
       Climate Solutions by Rob Painting
       @Ed Davies, New Zealanders don't heat their homes? Planning on moving to NZ from South Carolina early next year. Should I stock up on really warm clothing?
79684. BBD at 22:42 PM on 11 July 2011
       A Detailed Look at Renewable Baseload Energy
       KR

       You keep returning to UK, and UK only - that's less than 0.2% the land area of the Earth - you are focusing on local issues rather than global.

       I have always been clear to distinguish between UK and global issues (eg in discussion of wind power above). This is a misrepresentation. Your reading of the discussion above is similarly careless. Time to sharpen up.
79685. BBD at 22:39 PM on 11 July 2011
       A Detailed Look at Renewable Baseload Energy
       Tom You are making a hash of this. I think you should take deep breath and slow down a little.

       BBD @236 read 230 (and David Mackay) again. David Mackay quotes 100 Watt insolation per meter squared laid flat in England. 100*0.15 efficiency times 1 million meters squared per km squared = 15 million Watts collected [etc]

       No. See here. Please read and re-read this until you have absorbed its meaning completely.

       "All the world’s power could be provided by a square 100 km by 100 km in the Sahara.” Is this true? Concentrating solar power in deserts delivers an average power per unit land area of roughly 15 W/m2. So, allowing no space for anything else in such a square, the power delivered would be 150 GW. This is not the same as current world power consumption. It’s not even near current world electricity consumption, which is 2000 GW. World power consumption today is 15 000 GW. So the correct statement about power from the Sahara is that today’s consumption could be provided by a 1000 km by 1000 km square in the desert, completely filled with concentrating solar power. That’s four times the area of the UK. And if we are interested in living in an equitable world, we should presumably aim to supply more than today’s consumption. To supply every person in the world with an average European’s power consumption (125 kWh/d), the area required would be two 1000 km by 1000 km squares in the desert.

       Let's be absolutely clear: - MacKay uses 15W/m2 energy density for desert sited CSP - Based on this assumption, the area of desert sited CSP required to provide 23TW is 1,533,333 km2. Unless you can show that there is an error here, you must concede this point.

       LAGI gives the conversion efficiency (2) as 0.2

       [Please state units in further discussion.] No. LAGI does not use a conversion efficiency. It uses 0.2kW (insolation) and omits the panel conversion efficiency entirely. Once again, here is where they make the mistake:

       We have our capacity in KW so in order to figure out how much area we’ll need, we have to multiply it by the number of hours that we can expect each of those square meters of photovoltaic panel to be outputting the .2KW capacity (kilowatts x hours = kW•h).

       Look: "the .2kW capacity". See? That's 200W/m2. Based on real-world installations, you're doing well to get 15% and it doesn't matter if it's SPV or CSP (well, actually it does - CSP is the better choice. What matters is that the conversion efficiency has not been factored into the LAGI analysis. That's why they think you can get 23TW out of 500,000 km2 and MacKay knows it will take ca 1.5 million km2 of desert sited CSP I repeat: you are rushing and being careless. Read this again. Then go back and read #236.
79686. Trueofvoice at 22:38 PM on 11 July 2011
       The Medieval Warm(ish) Period In Pictures
       @ Eric, #11 Your link to Baikal Science confirms Mann's analysis. The areas it identifies as having significantly warmd during the MWP (Taymir and Putoran, are also labelled in Figure 1 above as having warmed. The area of the Ural Mountains discussed in your link to Demezhko are also represented as having warmed in figure 1. As you're currently 0-2 I'm not going to bother with your link to Solomina.
79687. BBD at 22:02 PM on 11 July 2011
       A Detailed Look at Renewable Baseload Energy
       Dump all preconceptions. Clear the mind and start afresh: #236
79688. BBD at 22:01 PM on 11 July 2011
       A Detailed Look at Renewable Baseload Energy
       Tom Curtis KR Neither of you has understood the argument summarised at #236. In fact you do not even appear to have read it. Try again please.
79689. Eric the Red at 21:59 PM on 11 July 2011
       The Medieval Warm(ish) Period In Pictures
       The MWP has been acknowledged as the last period of globally warm temperatures (not just NH as claimed above). The global temperature anomalies are similar to today, although some differences may exist. Whether that period was warmer than today is still open to debate, as different proxies present different results. The comparisons are important as they can reveal changes which have occurred in the past century (not just 30 years) with those that have occurred in the past. In order to show that today's warming is unprecedented, it has be larger in magnititude and more rapid than previous episodes. In addition to the questionable sea surface temperatures, other work has shown significant warming in Russia compared to Figure 1 above. http://hal.archives-ouvertes.fr/docs/00/29/81/68/PDF/cpd-3-1-2007.pdf http://www.baikalscience.org/?cat=12 Russia also experienced the MWP at different times, earlier in the West, later in the east, with temperatures warmer than the present by 1C or more. http://www.pages-igbp.org/products/abstracts/solomina.pdf
       Response:

       [DB] "The MWP has been acknowledged as the last period of globally warm temperatures"

       Citation?  As it stands, a nonsensical statement.

79690. ranyl at 18:56 PM on 11 July 2011
       Climate Solutions by Rob Painting
       Ranyl - how do you make do without a fridge? Have no dairy or meat and can't drink alcohol and live in moderate climate, so not really a problem. Keep stuff in larder like room on the north side of the house with no window. Most things keep for a reasonable while especially in winter. An evaporation fridge would keep things cool as well, and in hot climates evaporative cooling was traditionally utilised and a fridge is a big power user.
79691. Mark Harrigan at 18:41 PM on 11 July 2011
       Climate Solutions by dana1981
       To actually thoughtful #90. I'm disappointed in your response - not so deserving of your moniker. You have made an accusation to me of being a stealth denier which i have rejected and not really considered the point I am trying to make. I really don't think you have read or understood my post. I am not denying the potential of human imagination - indeed I hope we can rely on it. But I want to argue and progress from reality not wishful thinking Your wishful thinking appeal is selective on based on emotionalism. I could point out that people have imaginged travelling to the stars and communing with the dead for centuries but it hasn't happened yet. All the successful human endeavours you point to (flight and going to the moon) were based on sound evidence, data and experimentation, as well as imagination. Not simply wishful thinking appeals to what we "want" to happen (Einsteins achievement is not a valid comparison - though it too was based on the above) So yes, I agree we need that imagination but I am simply pointing out that we need to use real evidence to argue the case for renewables. The sort of appeals you make works with the already converted but won't win over the general populace who are vulnerbale to arguments from the "dark side" and are all too ready to ridicule any claims that we make for renewables that cannot be supported. I prefer to work from what we know can be done and progress from there (I think if you examine the actual history of the scientific achievements you reference you will find that that was how they were done)
79692. Rob Honeycutt at 18:34 PM on 11 July 2011
       Climate Solutions by dana1981
       quokka... That link didn't work for me. It may be the link or my being in China. Not sure.
79693. Tom Curtis at 18:01 PM on 11 July 2011
       Climate Solutions by Rob Painting
       Paul D, how about a straight forward solar hot water system instead - or are only hair shirts green enough?
79694. Paul D at 17:51 PM on 11 July 2011
       Climate Solutions by Rob Painting
       How about a solar shower?? Designed for camping and military use, but can be used in the summer as an alternative to the usual powered shower.
79695. Rob Painting at 16:52 PM on 11 July 2011
       The Medieval Warm(ish) Period In Pictures
       Alec - If you have some better way of comparing the MWP with modern-day temperatures I'm all ears. I considered the point you raise when writing the article, but I just wanted to see what you had to add, before answering.
79696. Doug Mackie at 14:05 PM on 11 July 2011
       OA not OK part 4: The f-word: pH
       Oh, all right (prodded by co-author)....... umm ok thanks (OK stop prodding. There I said it. It's your fault for leaving responding to the grouchy one. Pollyanna I ain't. What? Oh for goodness sake. All right. All right.) Thank you for helping (Better?)
79697. muoncounter at 13:42 PM on 11 July 2011
       2010 - 2011: Earth's most extreme weather since 1816?
       Severe weather, indeed. July 5 Phoenix dust storm in pictures and with some meager NWS analysis.
       Response:

       [DB] Welcome back; you're late.

79698. RW1 at 13:42 PM on 11 July 2011
       The Last Interglacial Part Two - Why was it so warm?
       What was the previous interglacial globally average incident solar radiation?
79699. scaddenp at 13:33 PM on 11 July 2011
       Are you a genuine skeptic or a climate denier?
       I've been thinking pretty hard about the question of mitigation policies for libertarians. Scratch a skeptic and you tend to find a right-wing/conservative. Furthermore, I haven't found any libertarians that are not somewhere on the not-happening/not-us/not-bad spectrum. While I guess that its possible that right-wing genes somehow provides a better understanding of climate physics than climate scientists have, it seems more likely to me that a clash with political values inhibits a proper evaluation. Some of this might be simply a conservative resentment of a changing world but I am hypothesising that for many/most? the first inkling of global warming comes from hearing about an unacceptable proposed solution. If it is better to reduce CO2 emissions rather than adapt, then we need effective proposals that don't offend these values. I have found very few libertarians even prepared to think about it. Cudoes to Eric here and to others who have taken up the challenge in email over the past couple of years. I am taking right-libertarians political theory in a nutshell to be: The right to individual liberty of action providing it does not infringe on the rights of other rights-respecting citizens.Individual responsibility for the consequences of these actions. Government is as minimal as possible with roles of protection from external aggression, maintenence of legal system to enforce contracts, and such police as needed to protect citizens from rights violation by theft, fraud or force. The solutions to climate change most acceptable to this group are ones that also promote the libertarian agenda. Eric's suggestion of insurance regulating safety and privatization of roads with appropriate cost are examples. Unfortunately, these mostly dont seem to very effective solutions - they depend on somehow getting alternative costs below coal without raises coal price to be effective. What if you cant? The problem is that the costs of producing power from coal dont include external and future costs but there is no easy mechanism that I can think of for adding in uncertain future costs. What does the theory do in these cases? "Cap and trade" attempts to add these cost to carbon but it is an anathema to the Right for which it is designed to appease. Killing subsidies on fossil fuels should be a no-brainer - in fact killing all industry subsidies and returning the savings as reduced taxes should be more than acceptable since subsidies imply coercive support of government-favoured industries. To an outsider, it seems US big business simply bribe their representative with campaign funds to get tax support in return. It might be asking a bit much for Cato Institute to be waving this banner but I would regard it as litmus test as to whether its truly is designed to promote libertarian values or merely a political tool to protect some very rich interests. A bigger sticking point however is likely to be that subsidy removal is proposed by a Democrat president. Government action is portrayed as theft of the rights of fossil fuel property holders but is their situation any different from asbestos property holders? Our knowledge of the toxicity has improved in both cases and the response of the industry has been rather similar. As far as I can see, libertarian theory struggles with issues where the free action of many individual results in a rights violation. Examples would be passive smoking, pollution control - and climate change. How can a citizen with say, a lung condition, sue those who choose to smoke in public, or not buy emission-control for their vehicles? No one individual is at fault and no mechanism exists for rights protection that I can see. It is interesting to see libertarians responding with denial on passive smoking too. Government action is permitted by the right in the case of external aggression so it seems self-preservation values override those of liberty. This I think explains the ghoulish preoccupation by AGW-activists with ice-melt and extreme weather. They are trying to trigger a self-preservation response. But suppose your country wont suffer too badly under the effects of climate change and the really bad stuff happens elsewhere? Does rights-respecting only apply to citizens of your country? Your state even? If not, then how is this rights-conflict arbitrated? In an ideal world, it should be possible for a person to choose to take no mitigating action in belief that science is wrong, provided that person is also willing to take their share of the responsibility for liabilities for adaption and compensation. However, I cant think of any mechanism by which this could work for a multi-generational problem like climate change. People object to paying for the "sins of their fathers" (though the same people appear to be quite happy to pass the costs to another generation). This is a tough problem. We are born with a desire to do what we like and instinct for self-preservation,whereas respecting others rights and taking responsibility are learned behaviours. To me, libertarianism seems a theory for the empty frontier rather than a heavily populated planet, but I would really like followers of the theory to face up to the problems above with some workable solutions instead of denying such problems exist. Solutions that would get whole-hearted support are needed and for that I think a value other than liberty/preservation needs to be invoked.
79700. Pete Dunkelberg at 12:52 PM on 11 July 2011
       The Last Interglacial Part Two - Why was it so warm?
       How warm was it? Paleoclimate Implications for Human-Made Climate Change:

       Paleoclimate data help us assess climate sensitivity and potential human-made climate effects. We conclude that Earth in the warmest interglacial periods of the past million years was less than 1{\deg}C warmer than in the Holocene. Polar warmth in these interglacials and in the Pliocene does not imply that a substantial cushion remains between today's climate and dangerous warming, but rather that Earth is poised to experience strong amplifying polar feedbacks in response to moderate global warming. Thus goals to limit human-made warming to 2{\deg}C are not sufficient - they are prescriptions for disaster. Ice sheet disintegration is nonlinear, spurred by amplifying feedbacks. We suggest that ice sheet mass loss, if warming continues unabated, will be characterized better by a doubling time for mass loss rate than by a linear trend. Satellite gravity data, though too brief to be conclusive, are consistent with a doubling time of 10 years or less, implying the possibility of multi-meter sea level rise this century. Observed accelerating ice sheet mass loss supports our conclusion that Earth's temperature now exceeds the mean Holocene value. Rapid reduction of fossil fuel emissions is required for humanity to succeed in preserving a planet resembling the one on which civilization developed.

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