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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] -
scaddenp at 07:39 AM on 12 July 2011Climate Solutions by Rob Painting
Should also ask you what part of NZ you are moving to? Auckland has mangroves and thinks 5 deg C is freezing. From Invercargill, there is nothing between you and Antarctica and 28 deg C would seem like the end of the world. -
Albatross at 07:30 AM on 12 July 2011The Medieval Warm(ish) Period In Pictures
Sphaerica @20, Good points. And let us not forget this:
Comparison of temperature reconstructions, re-centered to match CRUTEM NH land record (based on each reconstruction's period of overlap).
[Source]
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Rob Painting at 07:28 AM on 12 July 2011The Medieval Warm(ish) Period In Pictures
Eric Red - "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" So you comment without actually reading the post? How can global temperature anomalies be similar to modern-day when North American glaciers were growing in the MWP?, and when the central and eastern tropical Pacific was much cooler than the 1961-1990 reference period? -
Doug Mackie at 07:22 AM on 12 July 2011Ocean acidification: Coming soon
Camburn: Since we have not heard otherwise, we trust you have found the explanations thus far to be sufficiently robust to satisfy your expectations. -
Bob Lacatena at 07:16 AM on 12 July 2011The Medieval Warm(ish) Period In Pictures
18, Eric the Red, First, did you actually look at the papers you linked to? The last, Kellerhals et al, shows current temps substantially higher than the MWP.
The first, Cook, shows the MWP to be a fractionally present bump not much greater than other temps in the period, and also much lower than current temps.
So what exactly are you trying to prove?
And even if you found 3 proxy studies that show what you want, you're missing both points. The first is that that is mere cherry picking. A careful analysis of the data shows that warming that is supposedly the MWP is not contemporaneous... one study shows a peak in 1100, another 1300, another 950. It's also not nearly uniform around the globe. While one study shows a warm period here, another location at that same time shows cooling.
There is no doubt that there was a MCA, but there is no evidence that it was global, substantial evidence that it was not, and substantial evidence (as you have so kindly provided yourself) that temperatures even regionally did not match those of modern times.
Beyond this, you missed the other main points, which are first that whether there was a MWP or not, it does not change the radiative physics which clearly show we are causing greenhouse gas warming now, and if there was a MWP, and it was as warm as temperatures are now, then climate sensitivity is high and your constant admonishment that you are sure that climate sensitivity is likely to be below 2C goes out the window.
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Dean at 07:09 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Hansen claims to have resolved the issue with the "missing heat"(e.g. fig 19) in a draft paper. Does any expert here have a simple summary of the difference between Hansen's and Trenberth's approaches? -
Albatross at 06:47 AM on 12 July 20112010 - 2011: Earth's most extreme weather since 1816?
EricRed @327, You, like Norman, seem intent on missing the point entirely-- I even bolded the text @326 and reproduced the figure from Trapp et al. (2007). You somehow missed this from my post @ 326: "You are conflating the more subtle changes by month or by seasons with the quite drastic changes observe during the course of the spring and summer (March-August). This is similar to stating that most locations experience marked temperature changes between winter and summer each year, so a few degrees of AGW is nothing to be concerned about. The studies I am referring (see Trapp et al. 2007 kindly provided by Tom Curtis here) to look at the changes between the mean MAM (March, April, May) conditions for 1962-1989 and how mean MAM conditions might look in the future, 2072–2099." They are comparing apples with apples, you are not. You and Norman are in fact hopelessly confused on this. Also, it is obvious that you have either not read Trapp et al. (2007, 2009), or you did read it but are incapable of following the science (and there is no shame in that, we can't all be experts at everything or even most things). I'll give you the same advice that I gave Norman: "I urge you to read Trapp et al. (2007) and Trapp et al. (2009)in their entirety." Otherwise it is very clear that you are pontificating and talking through your hat, and I have no intention of wasting any more of my time arguing in circles with you either. You both keep repeating the same incorrect notions, sadly that doesn't make them any more correct or real. PS: In retrospect asking you to read the paper when you are not an expert in the field and have preconceived ideas may not help. then again, Tom Curtis is not an expert in this field, yet he managed to correctly interpret the science in the papers. PPS: The point of me quoting Schaefer and Edwards was to demonstrate that Norman had not accurately reflected their findings. -
Albatross at 06:31 AM on 12 July 20112010 - 2011: Earth's most extreme weather since 1816?
Norman at 16:03 PM on 9 July, 2011 You say "I am reading the articles you link to (mostly abstracts). They are predictions based upon their models about what will take place. They seem to assume the lapse rate will stay the same and the warmer wetter air will have more energy to generate more intense storms. I do not understand the logic they used to arrive at that conclusion. That is part of what I am questioning." Actually, Tom Curtis provided you links to two of the seminal papers, not just abstracts. This glib dismissal of the science based on your incorrect and incomplete understanding of the science left me speechless. They did not "assume the lapse rate will stay the same", your claim in this regard is demonstrably false (see below), yet it seems to be your reason for dismissing their findings as you then go on to argue the strawman that you created. This is nonsense Norman. In fact, your whole premise for creating your argument about lapse rates just shows how out of your depth you are and how little you understand the science-- in fact, so confuse dis your reasoning that I had a hard time figuring out what you were trying to say. You also seem to be confusing meridional gradients with vertical temperature gradients (i.e., lapse rates), are far too focused on the role of differential temperature advection in creating steep lapse rates (forgetting the role of the Mexican plateau and strong diabatic heating in generating steep lapse rates over the southern Great Plains, for example) and under the misconception that Arctic air is somehow stored in the upper-levels of the troposphere. Yet, you seem to feel compelled to argue the experts in this field and dismiss their findings equipped only with your preconceived and misguided notions and Google. From Trapp et al. (2007): "The two quantitative measures of CAPE and S06 were computed at each model grid point, for each day during the RF and A2 periods, using the RegCM3 output at 00 UTC." To calculate CAPE they used the vertical profiles of temperature (the RegCM3 model has 18 levels in the vertical), which would by default include information about the vertical lapse rates. The profiles were not constant, nor were the lapse rates. From Marsh et al. (2009): "The atmospheric portion of the CCSM3, the Community Atmospheric Model 3 (CAM3), is a spectral model with 85- wavenumber triangular truncation (approximately 1.4° at the equator) in the horizontal with 26 terrain-following hybrid levels in the vertical. The numerical scheme used in the CAM3 is an Eulerian spectral transform with semi-Langrangian tracer transport and semi-implicit leapfrog time stepping (Collins et al., 2006). CAM3's vertical resolution contains 4 levels below 850 hPa and 13 levels above 200 hPa (topmost being 2.2 hPa)." Again, the temperature profiles were not constant/specified. Again, any changes in the lapse rates would be reflected in the CAPE values. Please do not respond to me Norman, I and others have wasted hours of our lives drafting these posts and trying to explain the science to you, all to no avail it seems. I'm done here. PS: I have no idea what compels people to think that climate science and complex issue such as severe storms are an open house to speculation and 'debunking'; that equipped with Google and their misguided and shallow understanding that the science and physics can be dimissed or overthrown. It is infuriating to say the least. I am pretty well educated, yet have no intent or drive to argue with an engineer or oncologist that they have gotten something wrong because I happen to think differently, or because a result is not intuitive to me (nor should it be, I am not an expert in that field) and have access to Google. So it blows my mind to see self-professed 'skeptics' on the internet passionately arguing the physics and science on all aspects on climate science (oceanography, radiative transfer, physics, modelling etc.). Worse yet, when presented with the physics and facts, they then contort all kinds of excuses to dismiss them rather than using it as an opportunity to learn. -
scaddenp at 06:31 AM on 12 July 2011Climate Solutions by Rob Painting
Trueofvoice - central heating and double glazing are rare. Insulation levels are low (estimated that 600,000 home are uninsulated period in a country of 4m). Talking to visitors, we do indeed live differently, wearing warmer clothes. However, except in Central Otago and mid North Island, it doesnt get that cold. Winter frosts except in upper quarter yes, but seldom below zero. Normally people heat one or two rooms (wood burners often, but heat pumps are making a big impact). -
Kevin C at 06:27 AM on 12 July 2011Trenberth on Tracking Earth’s energy: A key to climate variability and change
Muoncounter #3: If there is an increase in the net energy budget, then either more energy is coming in or less is going out. If it's not the sun, then doesn't that leave either albedo (changing the absorption of incoming radiation) or greenhouse effect (changing the outgoing radiation)? What else is there? The change in figure 4a is not small: The difference in net energy flux from 2000 to 2009 in figure 4a is nearly 1W/m^2, and half of that in the last 2 years. That's equivalent to adding ~80ppm of CO2! Can weather cause fluctuations that big, or is it change in natural or anthropogenic forcing? -
Eric the Red at 06:05 AM on 12 July 20112010 - 2011: Earth's most extreme weather since 1816?
Albatross, Your last two paragraphs above seem to be saying the same thing, rather than being contrasting. In fact, if you eliminate April from the first paragraph and wind from the second, they are the same. If May becomes similar to July, then severe storms should diminish in May and June, with July and August diminishing further. -
LorenCobb at 05:49 AM on 12 July 2011SkS Weekly Digest #6
EDITORS ATTENTION NEEDED! The link in your "News Bites" section that says "Climate Change May Pose Biggest Security Threat" does not go to the correct URL. Instead of linking to the intended article, it links to a Skeptical Science blog-editing page which needs an administrative password.Response:[dana1981] Thanks to you and Byron Smith for the correction. Link fixed.
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Albatross at 04:33 AM on 12 July 20112010 - 2011: Earth's most extreme weather since 1816?
#314 Norman at 14:59 PM on 9 July, 2011 You ask "The question to you would be why do severe storms diminish in July and August even though that air is the warmest and contains the most amount of water vapor (fuel for storms)?" Norman, you may not realize it but your question is quite ridiculous in the context of what the research shows and int he context of what I said-- your question makes no sense in relation to what I said. You are conflating the more subtle changes by month or by seasons with the quite drastic changes observe during the course of the spring and summer (March-August). This is similar to stating that most locations experience marked temperature changes between winter and summer each year, so a few degrees of AGW is nothing to be concerned about. The studies I am referring (see Trapp et al. 2007 kindly provided by Tom Curtis here) to look at the changes between the mean MAM (March, April, May) conditions for 1962-1989 and how mean MAM conditions might look in the future, 2072–2099.
I urge you to read Trapp et al. (2007) and Trapp et al. (2009) in their entirety. They are not talking about the "new May" becoming similar to the present July, for example. One has to compare apples with apples. This is a very important point, and one that you repeatedly keep on missing. I do not know whether this is intentional on your part, or simply because you are so far out of your depth on this complex issue.
Marsh et al. (2009) made similar findings for Europe concerning the potential for an increase in severe thunderstorm episodes over Europe. They found that:
"Preliminary comparisons of the CCSM3's 21st century simulation under the IPCC's A2 emissions scenario to the 20th century simulation indicated a slight increase in mean CAPE in the cool season and a slight decrease in the warm season and little change in mean wind shear. However, there was a small increase in favorable severe environments for most locations resulting from an increase in the joint occurrence of high CAPE and high deep layer shear."
They add that:
"At best, one can say that the CCSM3 predicts the number of favorable severe environments will increase in a future characterized by anthropogenic warming."
You say "In the United States the most severe storms occur April, May, June and diminish in July and August (tornadoes, hail, rain, lightning)"
Funny how we can look at the same graphs and arrive at different conclusions. According to the database compiled by Schaefer and Edwards, they say "May and June are the peak months for the occurrence of tornadoes and large hail. In contrast, July and June are the top months for wind storms." April and July are the next highest for all tornadoes, respectively.
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BBD at 04:06 AM on 12 July 2011A Detailed Look at Renewable Baseload Energy
CBDunkerson #264Thus, 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.
Well, it's average performance that counts. So what concerns us is this: 20% x 250 = 50W/m2 Slighly less idealised: 15% x 200 = 30W/m2 MacKay gives a real-world estimate for CSP of 15W/m2. I think he's right, as efficiency will no doubt rise over time. However, current real-world plant power density is even lower than assumed above. There are a number of reasons for this. Here are some real-world numbers:Europe’s first commercial solar tower, PS (Planta Solar) 10, completed by Abengoa Solar in Sanlúcar la Mayor in 2007, is rated at 11 MWp. With annual generation of 24.3 GWh (87.5 TJ, 2.77 MW), its capacity factor is 25%. Its heliostats occupy 74,880 m2 (624 x 120 m2), and the entire site claims about 65ha; the facility’s power density is thus about 37 W/m2 factoring in the area taken up by the heliostats alone, and a bit more than 4 W/m2 if the entire area is considered. PS20 (completed in 2009) is nearly twice the size (20 MWp; 48.6 GWh or 175 TJ/year at average power of 5.55 MW and capacity factor of nearly 28%). Its mirrors occupy 150,600 m2 and hence the project’s heliostat power density is, at 36.85 W/m2, identical to that of PS10 but, with its entire site covering about 90 ha, its overall power density is higher at about 6 W/m2. Bright Source Energy’s proposed Ivanpah CSP in San Bernardino, CA should have an eventual rating of 1.3 GWp and it is expected to generate 1.08 TWh (3.88 PJ) a year and deliver on the average 123.3 MW with a capacity factor of just 9.5%. Heliostat area should be 229.6 ha and the entire site claim is 1645 ha. This implies power densities of 53.75 W/m2 for the heliostats and 7.5 W/m2 for the entire site. Again, no stunning improvements of these rates are expected any time soon and hence it is safe to conclude that optimally located CSP plants will operate with power densities of 35-55 W/m2 of their large heliostat fields and with rates no higher than 10 W/m2 of their entire site area.
So, again but with 10W/m*2: 10,000km2 = 100GW 100,000km2 = 1TW 2,300,000km2 = 23TW Smil's examination of the impact of packing factor on installation footprint finds the following energy densities for SPV plant: Olmedilla 85 GWh/year = 9.7 MW 9.7 MW/108 ha = 9 W/m2 Moura 88 GWh/year = 10 MW 10 MW/130 ha = 7.7 W/m2 Waldpolenz 40 GWh/year = 4.56 MW 4.56 MW/110 ha = 4.1 W/m2 -
actually thoughtful at 03:47 AM on 12 July 2011Climate 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. -
BobC at 03:38 AM on 12 July 2011CO2 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) -
Albatross at 03:34 AM on 12 July 20112010 - 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.
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BBD at 03:14 AM on 12 July 2011A Detailed Look at Renewable Baseload Energy
CBDunkerson "PS: 200 * 20% = 40. Not 20. " Whoops. Thank you. -
CBDunkerson at 02:58 AM on 12 July 2011A 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. -
BBD at 02:49 AM on 12 July 2011A 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. -
Tom Curtis at 02:46 AM on 12 July 2011A 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.
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muoncounter at 02:30 AM on 12 July 2011Trenberth 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? -
BBD at 02:25 AM on 12 July 2011A 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.
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Kevin C at 02:15 AM on 12 July 2011Trenberth 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! -
Byron Smith at 02:12 AM on 12 July 2011OA 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. -
BBD at 02:08 AM on 12 July 2011A 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. -
Peter Peete at 01:39 AM on 12 July 2011Venus doesn't have a runaway greenhouse effect
Hello, this a really nice article, I want to give a thanks for it. -
Humanracesurvival at 01:38 AM on 12 July 2011Trenberth 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. -
BBD at 01:34 AM on 12 July 2011A 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.
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