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BBD at 19:11 PM on 12 July 2011A Detailed Look at Renewable Baseload Energy
Tom You are not addressing #264. At #252, you said (and not for the first time - it is your entire argument):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%).
But that is exactly what LAGI does. It multiplies 200W/m2 by the estimate of 2000 hours p/a of direct sunlight: 200W/m2 x 2000 = 400kWh per m2 And on this assumption estimates: 500,000 km2 = 23TW Plant conversion efficiency is not calculated Instead of this:average raw energy density x plant conversion efficiency = average output
LAGI does this:average raw energy density = average output
200W/m2 x 2000 = 400kWh per m2 I show this, again, at #264. Please respond to this. Do not introduce any extraneous argument. Respond to this alone. Politely. You must: - show that it is incorrect or - admit that LAGI is in error # 264. -
Rob Painting at 19:04 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
Alec Cowan @ 13 & 19 - Okay so nothing constructive, I thought this might lead to some rational discussion - my bad. I think if you're wanting someone to rail against it should be Hubert Lamb? He's the one who started the MWP nonsense in the first place. -
Magnus W at 17:46 PM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
It would be very interesting to hear what Kevin have to say about the sulfur situation and possibilities of tracking the heat in the ocean with todays measurement systems... i.e. articles linked in comment 23 and 7. And I guess this also comes in to play: http://www.springerlink.com/content/akh241460p342708/ we estimate that up to one third of the late twentieth century warming could have been a consequence of natural variability. -
Dikran Marsupial at 17:25 PM on 12 July 2011CO2 has a short residence time
The adjustment time depends on the net difference between total uptake and total emissions. It is true that the uncertainty in the estimates of the magnitude of the individual environmental fluxes is large compared with anthropogenic emissions, we don't need to know the magnitudes of the individual fluxes to obtain a much more certain estimate of their differences. Assuming conservation of mass, then dC = E_a + E_n – U_n where dC is the change in atmospheric CO2, E_a is anthropogenic emissions, E_n is total environmental emissions and U_n is total environmental uptake. Rearranging we get dC - E_a = E_n - U_n We can measure dC accurately via the e.g. the Mauna Loa data and anthropogenic emissions are estimated accurately (as energy use is generally regulated and/or taxed so governments keep good records). As we have an equality, the uncertainty on the right hand side is the same as the uncertainty on the left hand side. So while we don't know the magnitudes of E_n or U_n with any great accuracy, we have a method of constraining the uncertainty on their difference using the uncertainty in the difference of dC and E_a. If you build a one box model of the carbon cycle (i.e. a first order linear differential equation) and calibrate it using the observations of dC and estimates of E_a over the course of the Mauna Loa record, you end up with a residenc time of about three/four years and an adjustment time of about 74 years, which is in good accord with the figures given by the IPCC. I'll post a more detailed explanation in the (hopefuuly) not too distant future. As to C14, this approach gives an estimate of residence time, not adjustment time. The adjustment time is a measure of how quickly CO2 is permanently removed from the atmosphere; residence time is a measure of how rapidly carbon is exchanged between the atmospheric and oceanic/terrestrial biosphere reservoirs. The vast majority of the C14 from nuclear tests has not been permanently taken out of the atmosphere, just replaced by carbon dioxide containing lighter isotopes of carbon due to the vast exchange fluxes. The C14 data thus is a measure of residence time. Essentially the IPCC figures are entirely in accord with the piblished litterature on tracer measuement. -
Tom Curtis at 16:21 PM on 12 July 2011Over the tipping point
Artful Dodger @13, currently the annual increase in atmospheric CO2 is still less than annual human CO2 emissions. Therefore natural sources are still a net sink of CO2, and where we to stop all CO2 emissions tomorrow, the CO2 concentration in the atmosphere would start to slowly decrease. It is true that evidence is showing the natural carbon cycle is becoming less efficient as a sink for anthropogenic CO2. Further, it is true that we may be approaching one of several potential tipping points that would turn natural sources into a net source of CO2. Indeed, warming currently in the pipeline due to thermal lag may even take us over such a tipping point. Consequently it is possible that natural processes could take us to 1200 ppm CO2 by 2200, but it is not likely. In the event that we stopped all emissions in the next 10 or even 20 years, it is more likely than not that CO2 concentrations would decrease. But the longer we delay, the more likely that natural mechanisms will double or even triple CO2 concentrations. -
Artful Dodger at 15:19 PM on 12 July 2011Over the tipping point
Adelady #5: A CO2-balancing scheme may have worked in a pre-350 ppm world. However, our present situation is far worse because there are now more sources of CO2 (soil aeration, deforestation, permafrost, methane clathrates, etc...) than those caused by human burning of fossil fuels. In other words, EVEN if human emissions when to zero NOW, the Earth is still probably headed to 1200 ppm CO2 within 200 years. Maybe 800 ppm by 2100. We are in a deep hole, but still digging. Have you seen the video where a cruise ship Captain tries to avoid crashing into a dock, but can't stop the momentum of the ship? Well, imagine you are a passenger on that ship, and the only means you have to avert the crash is to move the Ocean! Because that is the equivalent task for the Public in averting Climate Change... As we capture CO2, the world Ocean simply gives up its sink of dissolved CO2 to maintain gas pressure equilibrium between the ocean and atmosphere. This is why Climate Change is unstoppable for millennia. The only reasonable solution is restoring the biosphere, and letting time take it's course. Do we have the wisdom and courage to take this action? Or will the Captains of Industry pilot Human Civilization onto the rocks? Remember who took the lifeboat seats on the Titanic... -
Daniel Bailey at 14:41 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
But of course, since the dissemblers would have us believe the MWP was as warm or warmer than today, the Arctic must've been mostly melted then, too, right? But actual evidence shows that the waters now entering the Arctic Ocean from the Atlantic Ocean are the warmest they've been in the last 2,000 years. Yet another MWP "Silver Bullet" (an underwater hockey stick, no less). Time for another Coors Lite... -
scaddenp at 14:36 PM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
RW1 - Sorry, this is weird. It sounds like you are thinking of this as photons being little balls bouncing around with a "history" of where that have been. Instead, this is a series of energy balances reflecting all energy transfer processes. Its unphysical to try and track a photon "history". Perhaps it would be clearer if looked how each flow was determined. -
scaddenp at 14:29 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
muoncounter - this is however the dynamic for glaciers on west coast of NZ. In deep shaded valleys (and with high rockfall load, the increased precipitation from warmer Tasman sea overrides the warmer terminus. I think the same dynamics affect glaciers in southern South America. I'd say you need data from past behaviour of the glaciers concerned to interpret the changes. That said, I think Eric is onto a rich vein of denial memes (eg Loehle is good construction; proxies are show cooler than MWP even if instrument doesnt; I guess Mann 2009 is wrong because its by Mann? -
intrepid_wanders at 14:28 PM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
I am unsure where the question of the missing heat is, R. S. Knox, David H. Douglass 2010; (Recent energy balance of Earth International Journal of Geosciences, 2010) is quite sufficient for explanation of the complexity. -
Tom Curtis at 14:06 PM on 12 July 2011A Detailed Look at Renewable Baseload Energy
Alec Cowan @268, there is a difference between being abbreviated (or simplified) and being wrong. In the former case there are relevant qualifications or conditions which are omitted for simplicity or brevity of exposition, but which are reasonably evident from context, or explained in more detailed work elsewhere (which is preferably cited or linked, but often not). In the latter case, the statement is simply false or misleading in the context regardless of any unmentioned qualifications. The unstated qualifications in this case are that the irradiance figure is the clear sky, daylight direct normal irradiance. Here are clear sky irradiance figures for Albaquerque, New Mexico (35.11 degrees North) for June 22:
Note that with 2-axis tracking, solar irradiance of 1000 W/m^is achieved for 8 hours of the day, with the sun having an altitude of approximately 78 degrees at noon. Between the tropics this would be a reasonable annual average.
On December 22, with a solar altitude of 32 degrees at noon, the 2-axis tracking clear sky, daylight direct normal irradiance still averages 800 W/m^2 for eight hours of the day:
As it happens, LAGI do link to a source for their 1000 W/m^2 figure, but google docs won't open it for me so I cannot comment on it.
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Camburn at 14:04 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
muoncounter: Woods hole was pretty excited about this, and to my knowledge, this temp study of the Sarasota Sea has never been disputed till now. I don't understand how Dr. Mann missed this. Woods Hole discussion of Sarasota Sea proxy data -
dhogaza at 13:58 PM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
A lot of the downward emitted LW is 'forward radiation' that last originated from the Sun, yet to reach the surface.
You need to quantify this, or, if you're too lazy, just point us to whatever denialist screed has raised the issue. Because hopefully they'll have quantified "a lot", and, of course (!), thereby prove that it's not coming from the GHG mechanism, proving some modern physics false, etc, etc ... -
RW1 at 13:54 PM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
I also dispute the way the diagram depicts 78 W/m^2 of the post albedo as being 'absorbed by the atmosphere' without ultimately getting the surface somehow. I certainly don't dispute that some of the post albedo is absorbed by the atmosphere (mostly clouds), but if any of this energy finds it's way radiated out to space without ever reaching the surface, it's trading off energy from the surface absorbed by clouds that would otherwise have be leaving the system at the TOA. Indirectly one way or another, the full post albedo has to get to the surface if COE is to be satisfied. The numbers don't work unless it does. Also, where is the return path of latent heat in the form of precipitation in the diagram? Surely, not all of it returns to the surface in the form of downward LW.Response:[DB] Please do not rehash the entirety of the 2nd Law thread. You were painstakingly corrected there, many times, by patient commentators.
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Camburn at 13:53 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
muoncounter: I dn't have access to the full paper, Kirkbride and Dugmore. Note tho, that the glaciers did not peak at the same approx time. With that in mind, remember how small Iceland is. I will also point out that the proxy data from the Sargosa Sea presented in my link does not match the reanalysis from the Mann paper ref fig 1. -
muoncounter at 13:53 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
Camburn#28: "a paper that has been cited 70 times about temperatures during the MWP" Good one. From 1999, the primary evidence presented for MWP temperatures dates from 1966: Graph is modified from Keigwin, L. D., 1966, The Little Ice Age and Medieval Warming Period in the Sargasso Sea: Science, v. 274, p. 1504 - 1508. Nothing much has changed in dating technology since the '60s. Or at least what little I remember of the '60s.Moderator Response: [muoncounter] Correction: Keigwin's Sargasso Sea paper was published in 1996. The referenced source (Bluemle, Global warming: a geological perspective, which appears in NDGS Newsletter, vol. 26 no. 2) misprints the date of Keigwin as 1966 in their Figure 4 caption. -
RW1 at 13:44 PM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
scaddenp (RE: 18), "Um, I think "back radiation" is radiation emitted from the atmosphere that strikes the surface. I cant see how "last originated from surface emitted" can make any kind of sense. It's a key distinction because the amount that last originated from the surface is what is actually determining the net surface energy flux, which is what ultimately is determining the surface temperature. A lot of the downward emitted LW is 'forward radiation' that last originated from the Sun, yet to reach the surface. Also, the kinetic energy (latent heat and thermals) moved from the surface into the atmosphere is in addition to the radiative flux at the surface, so any amount from it radiated back to the surface also did not last originate from surface emitted of 396 W/M^2, which is the just net energy flux at the surface (in the steady-state at least). -
muoncounter at 13:41 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
Camburn#27: "during the MWP the precip was extensively higher than present. That would cause the advancement of glaceriers even if the temperature was warmer." High precipitation plus warm temperatures = glacial advance? Not what Kirkbride and Dugmore 2008 found in Iceland: medieval glacier advances between the 9th and 13th centuries are firmly identified for the first time in Iceland. This challenges the view of a prolonged Medieval Warm Period and supports fragmentary historical data that indicate significant medieval episodes of cooler and wetter conditions in Iceland. -- emphasis added Koch 2008 is also a good short summary on this question: an advance of Llewellyn Glacier, which drains the northeast sector of the Juneau Icefield, at the time of the Medieval Warm Period, cannot be reconciled with temperatures similar to those of today. This evidence suggests that temperatures were significantly lower than at present during the Medieval Warm Period, calling into question the existence of prolonged warmth at that time. We conclude that the Medieval Warm Period is at best an ill-defined term that encompasses a number of possibly unrelated climate anomalies. -- emphasis added -
Camburn at 13:41 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
DB: Koch etal talks about the increased precipitation in the Western Conus. Here is a paper that has been cited 70 times about temperatures during the MWP: Global Warming: A Geological Perspective -
Camburn at 13:16 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
DB: The reason for the advancement of the glaciers is not certain. There are proxies from NA that show during the MWP the precip was extensively higher than present. That would cause the advancement of glaceriers even if the temperature was warmer.Response:[DB] Citations please. Unsupported claims carry little weight.
Precipitation increases do not necessarily translate into glacier advances. The mass balance between increased depositions in the accumulation zone have to outweigh losses in the ablation zone for glaciers to advance. Warming typically increases the size of the ablation zone and decreases that of the accumulation zone resulting in glaciers pulling back from their terminal moraines.
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Rob Honeycutt at 12:58 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
Eric... You might check out the first diagram in the article here. It seems that, for one, almost the entire central Eurasia region was actually cooler. I believe this is the point. There are clearly areas around the planet that show a MWP but the warming is heterogeneous in both time and place, and many areas of the planet were actually cooler during the MWP. This is completely different than today where we have extremely accurate measurements of the homogeneous warming. Call it a braided hockey stick with a very straight blade.Response:[DB] Interested parties may see also Koch and Clague 2011 wherein they show that that several glaciers in western North America and elsewhere in the world advanced during Medieval time and that some of these glaciers achieved extents similar to those at the peak of the Little Ice Age, a very cold period many hundreds of years later.
More discussion on this here.
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Alec Cowan at 12:48 PM on 12 July 2011A Detailed Look at Renewable Baseload Energy
@267 Tom, I only have read what I supposed a faithful quotation in #264. In the sentence "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)." the phrase between parenthesis is factually wrong unless that land is a small spot that changes location by the minute -though I don't understand why third person singular if 20% and 80% are striking the same SM so 20% is not the subject- In the best case, it is a sloppy way to say it. I have at least the excuse of hardly speaking English -in spite of me using my real name here what seems to suppose some kind of linguistic obligation-. The term capacity is not really a problem, though it suggest a technological limit. I don't need to be "sold" solar energy. But I wasn't born yesterday. Free energy like solar or petroleum has the cost of knowing where to find it -solar is easy about that- and later the cost of making it available where and when you need it. I think that many people is needing lessons of economy, not ecology or physics, so they can land safely at last. If the topic was feasibility of solar energy, of course it is. What surface is needed? Just within the same order of magnitude of paved roads and urban sprawl in the United States. -
heystoopid at 12:30 PM on 12 July 2011SkS Weekly Digest #6
To whom it may concern, there appears to be a mixed up link in News bites thus:- "Millions of African Climate Refugees Desperate for Food, Water" currently links to Science Daily story ;'Fire to Become Increasingly Important Driver of Atmospheric Change in Warming World' I believe the correct link to be:- http://www.ens-newswire.com/ens/jul2011/2011-07-06-01.html -
Eric the Red at 12:26 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
Do you have any references showing otherwise? -
Eric the Red at 12:24 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
Especially the global temps from Lohle. -
Eric the Red at 12:22 PM on 12 July 2011The Medieval Warm(ish) Period In Pictures
Yes, Notive how all the proxies show the MWP as being warmer than today?Response:[DB] Factually incorrect. See Martín-Chivelet et al.
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scaddenp at 11:51 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Um, I think "back radiation" is radiation emitted from the atmosphere that strikes the surface. I cant see how "last originated from surface emitted" can make any kind of sense. -
scaddenp at 11:40 AM on 12 July 2011The 2nd law of thermodynamics and the greenhouse effect
Rosco - this is basic version. This argument has been done to death at in here. I note some confusion on Trenberth. I suggest you might like to get your head around some basics at Science of Doom (and the many other articles there). In short, the physics is more subtle than you think it is. -
RW1 at 11:30 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Rosco (RE: 16), "I know they provide 333 W/sq metre "back radiation" but where do these joules come from to heat the atmosphere to the level where it radiates more than the incoming solar radiation?" If you read the tables in the paper, it's not really 'back radiation' but downward LW radiation received at the surface. Why he refers to this as 'back radiation' I don't know. The fundamental problem is downward LW at the surface has three potential sources: Some of it last originated from surface emitted LW, some of it last originated from the Sun absorbed by the atmosphere yet to reach the surface, and some of it last originated from the kinetic energy moved from the surface into the atmosphere while also radiates in the LW infrared. The term 'back radiation' generally implies downward emitted LW that last originated from surface emitted. The diagram makes it look like of the 396 W/m^2 emitted at the surface, 333 W/m^2 are coming back from the atmosphere, which is why it's confusing. -
Bern at 11:27 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
The question that comes to my mind after reading this excellent article, and the discussion above, is this: How does this affect model predictions for the next century? If Dr Trenberth is correct, that there is a decadal-scale sequestration of heat in the deep ocean, then this would, I presume, result in larger, decadal-scale oscillations in global temperature superimposed on the upward trend. It would appear that we're in a 'cool' period at the moment, which leads to the obvious conclusion that some time in the next few years to a decade or, we might see a very dramatic upward swing in global surface temperatures, as that deep ocean heat storage temporarily slows or even reverses. On the other hand, if Dr Hansen is correct, then as aerosols are scrubbed from more developing world power stations, we might see a similar upward surge in temperatures as the aerosol effects reduce. Either way, the next decade or two could see substantial surface temperature rises, but how would it affect temperatures later in the century? Would either of these options significantly change global climate model predictions of the long-term trend over that timescale? And if so, in which direction? -
RW1 at 11:12 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
As everyone knows, I have many questions for Kevin regarding the Energy Flows diagram.Moderator Response: (DB) Your best bet is to post them here. -
Tom Curtis at 11:11 AM on 12 July 2011A Detailed Look at Renewable Baseload Energy
Alec Cowan @265, nobody in this "discussion" or being discussed (ie, LAGI) assumes that "sun radiation direction is determined by gravity so every square metre of the planet gets plenty of it". LAGI discuss the potential of solar generation for sites located in southern Spain, North Africa, South West United States and Central Australia. These are all areas with high insolation and low cloud cover and, as shown by a comparison of Andasol data with their estimate, the estimate is reasonable, indeed conservative for most areas discussed. They do include a very few and small locations for which your criticism may be valid - South Africa, New Zealand, Seattle (what where they thinking), and Armenia. However, some of these can be fixed by simple relocation (South Africa to Namibia for example) and in others (New Zealand, Seattle) there are ample alternative sources of renewable energy (geothermal). That, however, does not detract from their point, which is not a proposal, but a demonstration of the capability of solar power. -
Camburn at 11:10 AM on 12 July 2011Ocean acidification: Coming soon
Doug: Excellent job. -
Rob Painting at 10:44 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Dean - have a read of page 44 in Hansen's paper, and the references cited therein. The top of the atmosphere satellite measurements are not without issues themselves.. -
Alec Cowan at 10:43 AM on 12 July 2011A Detailed Look at Renewable Baseload Energy
#263 erratum Dang! Volume of all oceans are three orders of magnitude higher. That volume of natural gas matches just the volume of the Caspian Sea and Black Sea together, or just more than a sixth of the Mediterranean's. -
Rosco at 10:36 AM on 12 July 2011The 2nd law of thermodynamics and the greenhouse effect
This is simply wrong. You are trying to compare a heat generating source - a human body - with a heat recipient. Our body loses heat by conduction of heat to the atmosphere and then by convection of warmed air. Clothes and blankets simply keep the warm air close to our body. We radiate heat at the same rate whether we are naked or clothed. We cannot heat up our immediate environment more than our core body temperature. Radiation is such a poor method of heat transfer that we can keep warm. Remember wind chill if you don't think convection is the major factor in heat transfer in an atmosphere. Your explanation also completely fails to deal with the requirements of thermodynamics which state that heat cannot flow from a hot object to a colder object unless there is work performed. Your answer totally fails to explain the work performed and therefore completely fails to refute the claim you set out to refute.Moderator Response: (DB) The law says NET heat cannot flow from cold to hot, so your comment is self-refuted. -
Ken Lambert at 10:32 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Very much appreciate Dr Trenberth coming on to SKS. Well done John Cook. At first glance, the article is a comprehensive summary of the existing state of uncertainty regarding the energy imbalance and the location of the missing heat. Will Dr Trenberth be answering any questions on SKS?Moderator Response: (DB) Dr Trenberth could not guarantee that time would permit him to do so; feel free to place any questions here in case he is able to do so. -
muoncounter at 10:30 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Dean#7: "As far as I'm concerned, emissions of sulphate aerosols has been increasing globally in the 2000:s due to the Chinese rapid rise," Even that's not so clear. See Has Sulfate Pollution from Asia Masked a Decade of Warming? for a short discussion. Between 2003 and 2007, global sulfur emissions have gone up by 26 percent. In the same period, Chinese sulfur dioxide emissions have doubled. ... sulfur dioxide emissions rates in China ... began to decline in 2006 after China began installing large numbers of flue-gas desulfurization (FGD) devices in coal power plants. -
Alec Cowan at 10:23 AM on 12 July 2011A Detailed Look at Renewable Baseload Energy
Well, based on the evidence shown, I don't know who is more deadly wrong, they who assume that sun radiation direction is determined by gravity so every square metre of the planet gets plenty of it -they must live inside some sort of Dyson sphere- or they who assume that the year has 2000 hours. Efficiency of 10, 15 or 20%, who cares? One has a wrong assumption in one term, the other one has two inconsistent values in a product. In my neck of the woods, with an overall efficiency of 15%, and taking into account local heliophany, I'd have 0.36 KW-h per day and horizontal square metre in June and 1.01 in December, that is 270 Kw-h a year. With a square metre of solar panels placed at an angle of 45° and the same efficiency of 15% I would get 380 Kw-h a year with peaks in the last days of Winter (heliophany is not constant through the year). And I'm at a 35.5° latitude what qualifies as mid-latitude, and I get 1,150mm of rain a year, with an heliophany of 71%, so this is no dessert at all but one of the most fertile plains in the world. I'd got 270 Kw-h from an horizontal square meter and 380 from a well oriented one with an efficiency of 15%. So, anyone can see which one was wronger: 400 KW-h with 20% efficiency or 60 KW-h with 15%. I don't have an efficiency of 15%. I hope I'll do in the future. The rest of it is out of discussion: I know what I'm talking about and I'm not interested in other opinions about what happens in the roof of my home. If someone disagrees, consider it a private matter. -
michael sweet at 09:57 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Here we see real skepticism at work in science. Hansen has proposed that aerosols reflect more heat into space. Trenberth proposes that the missing heat has been absorbed into the deep ocean. Hansen is skeptical of Trenberth's results and Trenberth is skeptical of Hansen. Both of them will marshall their data to determine which is more correct (it may be a combination of both effects). In the end the data will determine who is correct. This is an example of real climate scientists debating the data. Both Trenberth and Hansen agree that strong action is needed to counter the problems caused by BAU. -
Dean at 09:46 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Rob #8: Thanks again for the info. Just one issue that I still think it is not clear: Reflecting aerosols will obviously mean less heat going into the oceans. But the reflected sunlight should also reduce the TOA balance, which is measured. So at least in the simplest model, aerosols cannot explain the "missing heat" while both the ocean heat content and the TOA energy imbalance will decrease. -
Dave123 at 09:35 AM on 12 July 2011Climate Solutions by dana1981
Sorry editing problems using droid. Will come back to this later. -
Dave123 at 09:34 AM on 12 July 2011Climate Solutions by dana1981
PaulDI've been on the road for a few days, and thinking and your .... challenging PaulD- I've been on the road for a few days, and thinking and your .... challenging... post. I live in the midwest of the US. I have allergies, like many people. Leaving windows open is less than optimal, requiring ineffective medication that can leave me drowsy. Closing the windows requires the use of AC otherwise indoor temperatures will rapidly exceed anything bearable...and I have to sleep to both maintain my health, and to keep my job that pays for my health insurance. I thought the point of Dana's challenge is what we are doing relative to where we could be, not necessarily some absolute standard, otherwise we spring the trap laid by deniers who point to Al Gore not living in a hut in the woods foraging for food. But I find it hard to beleive that anyone other than a denier posting here doesn't know enough about our industrial ecosystem to get how fragile and dependent on cheap resources it is, or what we stand to lose if it breaks. I don't really want to go into my personal medical history here, but I really do mean it that I can count something like 5 times I would be dead without modern medical technology.... and NOT because of my lifestyle either. I'll give one example- mitral valve repair surgery... open heart. All of the diagnostics- trans thoracic echo cardiograms, tranesophageal echos, CT scans, angiograms require modern (last 15 years) computer technology. This means chip fab technology. Chip technology requires advance polymers for masking, the safe use of higly purified and highly toxic materials including phosphine and arsine. It requires a pre-existing computer infrastructure to create and test the circuit design (bootstrapping), create the mask design and huge, computer controlled machines to burn the mask into the chip. Etching the chip requires highly pure hydrofluoric acid and highly pure water (no, not distilled water...water that has megohm resistance needs to be purifided by reverse osmosis technology, which requires its own specialized polymer membrane technology. The surgery itself is safe at a 97% level because of advances in technique and anaesthesiology monitoring that reduce the operating time and thus the ris -
scaddenp at 09:29 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
A better link for Kaufmann courtesy of WUWT. From quick look, it uses Kaufmann's 2006 statistical model to relate forcings to temperature but with update forcing data including the new aerosol data which is up. Hansen also states "Global warming has been limited, as aerosol cooling partially offsets GHG warming" and argues that aerosols are understated in the models. Kaufmann cannot rule out natural variability but I think the Argo network will eventually make this clearer. -
Rob Painting at 09:16 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Dean, if one accepts Hansen is correct and that there is no 'missing heat' in the ocean because the models are wrong, then yes there is no imbalance. He could be right - but seems a bit light on evidence at the moment. On the other hand the warming found by Von Schuckmann & Le Traon is a bit more than that found in other recent analysis, so it does 'close the gap a little'. As for sulfates, although they do tend to wash out of the atmosphere within weeks to months, they can have a profound effect on cloud formation - the finer particles seeding smaller, but more numerous cloud 'droplets' - for want of a better word. Being smaller they are less likely to condense into rain, and they also make clouds more effective mirrors. So more sunlight is reflected back out to space. This effect is greater is the dry seasons, when sulfates are less prone to being 'washed out'. If Hansen is correct, this affects the energy budget because less energy is being received at the Earth's surface (there's far less incoming energy to account for). The climate models use an estimate of the aerosol cooling effect in their simulations, but if the ocean mixing rate is wrong in models (i.e. too efficient), the model match with 20th century observations is simply fortuitous. Seems a stretch. One would expect the budget doesn't balance for a number of reasons, the large uncertainty in measurements being a significant one, but also a greater aerosol cooling, deep ocean mixing and increased radiation to space (Katsman & Oldenburgh (2011) -
BBD at 09:11 AM on 12 July 2011A Detailed Look at Renewable Baseload Energy
All This is what we are discussing:average raw energy density x plant conversion efficiency = average output
Here's what LAGI does: - reasonably assumes 200W/m2 raw energy density - multiplies 200W/m2 by the estimate of 2000 hours p/a of direct sunlight: 200W/m2 x 2000 = 400kWh per m2 - and on this assumption estimates: - 500,000 km2 = 23TW Plant conversion efficiency is not calculated. Much of the ambiguity arises from LAGI's use of 'capacity' (emphasis added):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).
What capacity? What are we talking about here? MacKay includes a value for conversion efficiency. Say it's 15% (it doesn't matter; this is an example only). Remember:average raw energy density x plant conversion efficiency = average output
200 x .15 = 30W/m2 So: 30W/m2 x 2000 = 60kWh per m2 vs LAGI:average raw energy density = average output
200W/m2 x 2000 = 400kWh per m2 This is not esoteric. Can someone please come to the rescue. I'm tired. -
Dean at 08:29 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Thanks Rob, looking forward to your post. However, Hansen states in the beginning of chapter 11: "our calculated energy imbalance is consistent with observations (Fig. 19b), implying that there is no missing energy in recent years" This is different to your "closes the gap a little". As far as I'm concerned, emissions of sulphate aerosols has been increasing globally in the 2000:s due to the Chinese rapid rise, despite the western long term decline since the 1970:s. A reference. But even if this affects the surface temperature negatively, it is not obvious to me how/if this affects the energy balance accounting. If sunlight is reflected upwards again things cancel out, or? -
Rob Painting at 07:58 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Dean, Fig 19 relates to Von Schuckmann & Le Traon 2011 who find that the upper ocean from 2005-2010 has warmed significantly. I'm writing up a post on it at the moment. It doesn't resolve the 'missing heat', but rather closes the gap a little - down to a .59W/m2 imbalance. Hansen suggests that the shielding effect of aerosols may be greater than anticipated, and that the climate models match 20th century observations in that they underestimate the strong cooling effects of aerosols, but overestimate the ocean response because they mix heat too quickly down into the ocean, compared to chemical tracer observations. -
Paul D at 07:46 AM on 12 July 2011Climate Solutions by Rob Painting
TrueOfVoice said: "Should I stock up on really warm clothing?" The object of heating is to keep the human body at a temperature at which it can happily survive. So the question is, what is the most efficient way of doing that? I don't have central heating (I live in the UK) and these days tend to turn the thermostat down in the winter and wear more layers of clothing. The biggest problem tends to be others expectations, most buildings are heated in the UK with the assumption that people wear one layer of thin clothing, jumping out of their heated car into a heated building. Which means if you go out of your home and walk to a shop with about 6 layers of clothing on, you break out in a sweat when in the shop for to long. So the inefficiency of others and the legislation that says the working place must be a minimum temperature, means those that want to cut back are hindered. -
Alec Cowan at 07:39 AM on 12 July 2011A Detailed Look at Renewable Baseload Energy
To add to the dance of figures loosely related with the post: 9? 7.7? 4.1 W/m2? Wow! Brazil get some 0.8W/m2 in bio-ethanol in their best model crops. USA gets some 0.3W/m2 in bio-ethanol from corn. And land is no cheap because ... it produces a lot of sugar cane or corn! That land is better used for sun harvesting! On the other hand, USA managed to got many hundreds of TW during Hiroshima's blast, and using less than a cubic metre. And those 23TW so discussed and compromising the area of whole countries can easily be got from burning 40 milliard tons of coal per year, if you only want heat, an amount of heat that could melt 2,200 km3 of ice itself if you ignore the effect of more than 140 GTons of CO2 added to the atmosphere by burning it, which stands for that greenhouse gas rising some 17 ppm by year. But don't get dismayed by this as you can cut emission to a half or less by using petroleum and natural gas, all provided you only needed heat and you needed it in the same place the fuel is. But, obviously, bio-fuel and nuclear are very expensive while sun, wind, petroleum, natural gas and coal are 100% free -nothing sarcastic there, not at all-. And that may have been the problem from the very beginning. Well, we may or may not need in a period of thirty years some hundreds of thousands of square kilometers to harvest sun or at least 800 km3 of coal or oil, or 650,000 km3 of natural gas (more than half the volume of all oceans together), what I'm sure is here and there, and a 100% free too, as said, not in a sarcastic fashion but because it's true. Well, number crunching is over. It was very entertaining. What on Earth are you talking here about? and, how does that relate to the topic in the post? [Few adjectives were used in this, and none of them was harmed while making this comment]
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