There is a new paper in Science this week on changes to atmospheric visibility. In clear sky conditions (no clouds), this is related mainly to the amount of aerosols (particulate matter) in the air (but is slightly dependent on the amount of water vapour as well, which is corrected for in this study). The authors report that the clear-sky visibility has decreased almost everywhere (particularly in Asia) from 1973 to 2007, with the exception of Europe where visibility has increased (consistent with the ‘brightening trend’ reported recently). Trends in North American stations seem relatively flat.
There is another story that didn’t get as much press when it came out late last year but that is highly relevant to this issue – whether any of the efforts that the Chinese authorities to reduce air pollution ahead of the Olympics last year had any impact. To the extent that they did, they might point the way to reducing aerosols and other pollutants across Asia, but it might also reveal how hard it is to do so.
The press release and abstract for the Science paper link their results to the ‘global dimming’ trends we have reported on in the past, but it’s worth perhaps pointing out that previous studies (and the term ‘global dimming” itself) have referred to all-sky conditions. So that includes changes in clouds – which are obviously a big factor in how much sunlight gets to the surface. Looking at the clear sky conditions (i.e. only when there are no clouds) can help attribute changes to aerosols or atmospheric dynamics say, but since aerosols affect clouds (the ‘indirect effect’) as well as circulation too, it is only a partial estimate of the true impact of aerosols.
But getting back to the Olympics…. Monitoring of pollutants near the surface has improved enormously in recent years with the various satellite instruments now in orbit (MOPITT, GOME, OMI and TES for instance (sounds like a comedy revue team, no?)). These instruments detect specific frequencies where pollutants are known to absorb and so can give a birds eye view of where the pollutants are and how they are changing. Among other things, the satellites can detect ozone, NOx, SO2, the total amount of aerosols and carbon monoxide. Each of these have different atmospheric lifetimes and so can be used either to detect point sources (from pollutants that only last a short time) or long range transports of pollution (from the longer lived pollutants). NO2 (a big component of NOx – which lumps together NO and NO2all of the reactive nitrogen oxides), is very short-lived and so tells you a lot about local sources. Carbon monoxide has a longer lifetime (a couple of months) and so can show the long-range impacts. Many of these pollutants have related industrial sources (car exhausts, coal burning, industrial production etc) and so can be used as proxies for many other pollutants (such as specific aerosols) which can’t (yet) be directly measured.
What do the results show? The team at GSFC have released preliminary images from the NO2 analysis showing the before and during the pollution controls. In both images, Beijing shows up as a huge hotspot of pollution, but relatively, the levels during the Olympics were significantly smaller:
August 2008 levels were therefore about 50% less than a similar period the year before. Meanwhile values at other hotspots in China were steady or got even worse. So there was a significant effect, but the scale of the task was indeed Olympian.
Hank Roberts, thanks for the replies re OLR and Triana. Interesting stuff.
I have finished reading the Gerlich & Tscheuschner article, but have not fully digested it. Nor have I yet read the information at the links that Gavin provided the other day. However, even though I have not finished cogitating over this article, I do think that David Donovan’s recent post (194) missed the point that Gerlich & Tscheuschner made. They did not say that it was impossible for the atmosphere to radiate photons of IR downward. They were careful to say that the Second Law applies to heat transfer, not to individual photon events. The fluxes of IR photons that David mentioned are not inconsistent with the Gerlich & Tscheuschner article. The article says only that (in the absence of application of work) the net heat flux cannot be from a cooler atmosphere to a warmer surface. They are saying that there the net flow of heat must be from the warmer surface to the cooler atmosphere, which means that the cooler atmosphere cannot contribute warmth to the warmer surface.
This is a fascinating article. I intend to pursue it further as time permits. However, I will be out of town over the weekend and will not get back to it until sometime next week.
I agree that Gerlich & Tscheuschner covered a lot of ground. I also think that the failure of the translator to remove much of the German syntax is already making the article difficult to read. However, as I said, what is obscure is not always without value.
James, do you realize how your argument “the rest of the world could do with less” doesn’t make much sense until the rest of the world is at least brought up to your own living standards? Your speaking from a position of vast privilege in comparison. From their eyes, the computer you are staring at right now might seem like a huge overindulgence to ‘the rest of the world’.
Question: Why doesn’t ‘the rest of the world’ enjoy the living standards of the posters on this blog right now? What would it take to get them up to this level?
Michael, do you realize your argument “until the rest of the world is at least brought up to your own living standards” is self-defeating if you assume that will be attained using fossil fuels?
Do you understand the problems caused by increasing carbon dioxide in the ocean, and the length of time involved?
Assuming you believe James’s standard of living is the goal for everyone — with no change in efficiency or economy — is needed, that has no bearing on _how_ other people can reach the same level.
No one tries to build buildings like the Egyptians.
It took til the 1800s to mostly eliminate slavery, but it’s close to accomplished. No one can use that path any longer, it’s self-defeating. No one handles sewage like the Victorians either.
Same for fossil fuels. Look at ocean pH. There’s a limit.
If you could argue your great concern for other people in terms of outcome, with awareness of the limits of the old methods, rather than to promote outdated methods, you’d make more sense, I think.
Jim Bullis in 199.
I think your analysis is really far off where you conclude plug-in electric cars (Don’t you mean, plug-in hybrid?) are less energy efficient than the IC engine version we have now. Producing, refining, and moving crude oil and converting it to gasoline can consume 10% for a light crude oil, and up to 30% for heavy oil or tar sands. So the actual energy efficiency of the IC engine is lower that you indicate.
Modern electric power plants can get close to 45% conversion of heat to power, and over 50% for combined cycle natural gas turbines. Even allowing for transmission and transformer losses, and adjusting for the efficiency of the electric motors in the cars, the final energy conversion efficiency is clearly better than oil to gasoline to mile driven efficiency.
Also you are presuming that additional electricity generation will be coal fired… In reality, most plug-ins will likely charge at nights, and this is the best time for wind power generation.
I wouldn’t conclude that the experts who study this have it wrong. There clearly would be a positive impact in switching significant number of our current fleet over to plug-ins. But I do agree that the most positive impact to reduce carbon emissions, is shutting coal down. Coal is the big problem, and the biggest opportunity lies in reducing coal consumption.
Michael (202) — Read Jared Diamond’s “Guns, Germa and Steel” to obtain the answer to your first question. As to the second, what makes you think everyone would enjoy that?
Michael asks: “Why doesn’t ‘the rest of the world’ enjoy the living standards of the posters on this blog right now? What would it take to get them up to this level?”
Infrastructure, education (especially for girls), medical care and a government that gave a damn about them. In particular, transport in many developing countries is woeful. In Togo, where I was a Peace Corps volunteer, you could go 15 miles off the country’s main road and reach villages where kids never saw vegetables–or antibiotics for that matter. Communications infrastructure has already improved dramatically with cell phone technology being widely available in many countries. Of course energy per capita will have to increase, but there is no reason why this cannot be done with renewables–in many cases more easily than with a traditional “grid”.
Re: #120
My mistake, John P. Reisman
Re: #189
Patrick 027,
This is a good read. If only all of us had such notable patience with contrarians…for example, when someone claims the IPCC is political and/or “alarmist” then goes on to quote a few “climate science” articles in Investor’s Business Daily or Monckton, that’s usually when I tune out. Kudos.
David B. Benson, Ray lists out a few good examples right after your post. I can’t deny anyone the basics of life that I take for granted. I am not the kind of person that can sit here with a roof over my head and ask “would they really enjoy roofs over their heads?”. I don’t think a single person here can think like that with their conscience engaged.
Re 202 (snorbert zangox) – please see my comments referenced in comment 189 above –
“They were careful to say that the Second Law applies to heat transfer, not to individual photon events.”
But their conclusion implies that those individual photon events are impossible or screwy in some manner.
“The article says only that (in the absence of application of work) the net heat flux cannot be from a cooler atmosphere to a warmer surface. They are saying that there the net flow of heat must be from the warmer surface to the cooler atmosphere, which means that the cooler atmosphere cannot contribute warmth to the warmer surface.”
Based on that logic, I would advise you not to wear any jackets or coats or hats, etc, in cold weather. They are not actually any warmer than your skin, and thus cannot provide any warmth to you – they can not keep you warm. The idea that layers will protect you from the cold is based on fictitious physics.
The error in that logic?
In both cases, the greenhouse effect (by optical properties’ effects on radiative energy transfers) and blankets (insulation), the net flow of heat (radiant or otherwise) is from warmer to cooler layers, but the rate of flow (the energy flux) for a given temperature distribution can be slowed or sped up, thus requiring greater or lesser temperature differences to sustain a given flux.
A potential point of confusion with radiant energy transfer is that while net fluxes of blackbody radiation, between points of emission and absorption, are always from warmer to cooler, they may traverse layers of any temperature in between.
Re 202 – “This is a fascinating article.”
Much more fascinating and infinitely more informative regarding physical reality is the book I linked to in comment 144 above
Ray, I can totally get behind providing clean energy for the less fortunate. Restricting/outlawing coal or oil at the expense of the less fortunate – not so much.
Michael (209) — I agree completely with Ray Ladbury. My point was directed toward our over-consumptive, stress-filled way of life for many, if not most, in the United States of America.
I’ll quote Jeffrey D. Sachs from the most recent issue of Scientific American: “America ranks 22nd of out 23 high-income countries in public social outlays as a percentage of national income … As a result, the U.S. has the largest poverty rate, income inequality and per-capita prison population of any high-income nation, as well as the worst health conditions.”
Now I happen to know of several substantial Jatropha projects in India, Myanmar and Madagascar. These are beginning to provide biodiesel for local use and provide a cash crop for otherwise subsistence farmers. No fossil oil required, vegetable oil will do. No air pollution to control, either.
Contining to use fossil fuel at the expense of the oceans?
While this recession/depression is frightening, can we not accept the reduced carbon output all over the world as a small sacrifice to help us in our long term objectives? Driving has been down since the high gas prices last summer, manufacturing is dead worldwide. I would bet that the recession so far has reduced carbon emissions far more than 20 years of cap and trade, green technology could have done in a growing economy.
Michael Says (20 March 2009 at 2:33 PM):
“James, do you realize how your argument “the rest of the world could do with less” doesn’t make much sense until the rest of the world is at least brought up to your own living standards?”
First, my argument isn’t what you apparently think it is. It’s that quality of life is not a linear function of consumption, and particularly of energy consumption. I use less energy (and have less “stuff”) than most of my neighbors, yet I don’t see my quality of life being any the worse for it. Quite the opposite, in fact, especially these days.
Another point you seem to have missed is that there’s a basic contradiction between bringing everyone up to what you seem to assume is my own standard of living – equating that with a stereotypical American lifestyle, and my own attempts to improve my quality of life by selective removal/rejection of many aspects of that lifestyle.
“From their eyes, the computer you are staring at right now might seem like a huge overindulgence to ‘the rest of the world’.
A good example. It’s hardly an indulgence based on energy consumption, since it takes something under 20 watts (per PowerTop: http://www.lesswatts.org ) to run in staring-at-screen mode. (More on the occasions when I test number-crunching code, but that’s infrequent.) Could easily be run off a fairly small solar panel – and it’s not all that far removed from the “one laptop per child” model.
Furthermore, the computer & network access allow me to avoid consuming far more energy, since I can make a living without having to expend large amounts of (probably fossil fuel) energy on transporting myself to & from some office. I can also manage other parts of life – shopping on-line, electronic banking, exchanging letters with friends – at far less energy cost than traditional methods.
“Question: Why doesn’t ‘the rest of the world’ enjoy the living standards of the posters on this blog right now? What would it take to get them up to this level?”
The question requires making too many assumptions for me to give a meaningful answer. For instance, I’d guess that many of the posters here live in cities or suburban developments, which by my measure gives them a pretty low living standard. Maybe they have flat-panel TVs, cell phones, and so on, but I don’t, and I think NOT having them improves my quality of life.
So, if you’ll allow me a bit of Socratic method on the nature of wealth, which is richer: the man who wears a Rolex, or the one who has no need of a watch?
Re Paul Klemencic, #205
I think you misconcluded what I concluded.
Some of our key facts differ though. In 2005 coal fired electric power plants were 33% efficient for the whole USA. Similarly natural gas plants reached about 40% efficient. (I am doing this from memory. Look at http://www.miastrada.com for analysis and references.) The numbers you quote are achievable but not generally achieved results.
The heat engines can be compared quite directly, with the gasoline engine being something that is a current achievement at 38% being not much different than actuals for the USA power system.
Every situation requires some detail to work out but my main objection is against analyses that ignore the inefficiencies of the central power plants. The fact that Argonne and SAE seem to take this approach is very misleading since so many rely on authority rather than thinking things out themselves.
A well presented analysis is at http://www.spectrum.ieee.org/mar09/7928/2
However, I object even to this as to the way they think about how different fuels make respective grids different. Sure they do in the short term, but the real question is how does the whole system respond to an incremental increase in electric use, that is, charging an electric car, or anything with batteries. I maintain that it will all turn out to be a coal load until the last coal fired power plant is salvaged. Everything connects through economics.
For example, we in California like to think we are greener due to restrictions on coal usage. But we only get away with this because the rest of the country does not do the same. Thus the price of natural gas does not change much.
The process of fixing things needs to be thought out a bit more. If we tax coal by adding $3 to $4 tax to the present $1 per million BTU of coal this will make natural gas becomes an economically viable choice. Then the cost of fuel to make electricity will be about 2 to 3 times greater than it now is. If that is politically possible, just wait until the next shoe drops, which is that the natural gas price will spike; past experience shows it can double or triple without much reason at all. I doubt that Boone Pickens will sell his supplies for less than market price and I doubt that Putin or the Iran guy will give us a bargain price on LNG either.
I agree that coal is a huge problem, but I argue that trying to get it fixed by government action is not an approach that will work out very well.
But then, not a lot of people think much of my solutions either.
We will see what happens.
But it sure would be nice to see a little honest physics supporting our decisions along the way.
snorbert writes:
Absolutely right.
Absolutely wrong. To see why, remove the hyphen from the URL below and paste it into your browser:
http://www.geocities.com/bpl1960/JJandJ.html
Michael writes:
You’d prefer a billion people to be without fresh water when the glaciers they depend on for it are gone? You’d prefer 100 million climate refugees when countries like Bangladesh are under water? You’d prefer massive starvation because of vastly increased droughts in continental interiors?
Because that’s what you’re going to get if you DON’T restrict fossil fuels. Period.
Michael, Abandoning coal entirely is not an option in the near term (~10 years). In the longer term it is a prerequisite for the survival of human civilization. It is especially important to ensure that we meet the energy needs in the developing world with renewable energies. These are areas currently lacking in infrastructure, and the decisions we make NOW will lock them into either a polluting, outmoded energy infrastructure that is destined to fail or an infrastructure that is truly renewable. This is in fact easier than replacing our own decaying infrastructure.
It is not “either development or sustainability,” development is an integral part of sustainability.
Like it or not Michael, the climate crisis we face is very real, and the consequences could be catastrophic. We cannot ignore it even if our goals in doing so are noble.
Ray #202: Ray FWIW, I think you’re right and so is Hansen, the only difference I see is the date. IMHO industry are waiting for government, Shell recently dropped renewables but I think thier message was “no more credit, we need a price on carbon”.
Alan, my best guess would be that shell abandoned renewables because they did the analysis and found the economics wanting. With Steve Chu being a strong advocate of nuclear (at least before his political ascension) renewables will face a competitor they can not overcome on price alone.
One of the more curious aspects of the AGW issue is those most strongly aligned with the hypothesis seem to be the most antagonistic to what is obviously the most practical mediation. Clearly coal burning power plants, and the burning of fossil fuels for transport are the two key drivers of C02 emission. Swapping electric vehicles for ICE driven ones and swapping coal for nuclear seem to be the clear choice at least on an economic basis under the assumption that the vast majority of people do not want to radically change their lifestyle. Not to mention the health benefits that would accrue to the society from the removal of an incredibly toxic torrent of heavy metals which enter the environment as a result of burning coal.
I believe that it is this kind of misalignment which raises the hackles of many people who come to the issue with no preconceived notions.
Detouring to climate models, can anyone explain to me whether or not the GCM’s posit any large scale regional (continental or hemispherical) warming effects over 30 year time frames and if so what might they be and what would be the causes? I’m trying to make sense of the surface temperature record I saw in a recent paper which seems to show a pretty strong divergence of temperature trend between the northern hemisphere and the southern hemisphere.
Just in case anyone has not kept up to date on the “oceans cooling” problem that’s still in the news on my local TV stations, here are the facts:
http://earthobservatory.nasa.gov/Features/OceanCooling/page1.php
Patrick 027 (210), a thought that might shed some light (and which has been debated in RC with vigorous opposition I should admit) is that the IR emitted radiation from the vibration energy of CO2 molecules is not the same mechanism that generates the so-called blackbody (Planck type) radiation, and does not follow the same detail rules. For instance, whether the radiation is emitted or not or its intensity does not depend directly on the temperature as Planck radiation does. (Though temperature has an “indirect” effect through the Boltzmann constant and the quantum mechanical likelihood of an energy level being occupied or not.)
BTW, some very good posts that I’m still wading through.
Re 217 – Realizing the state of the art and what is possible may be quite different for each, my impression has been:
1. fossil fuel (and nuclear) power plants ~ 40 % efficient standard, often less; hydroelectric 80 % efficient, … but non-fuel sources of electricity are often given in terms of fuel equivalent, so 1 W of solar electric power would be ~2.5 W solar power fuel equivalent…
2. typical internal combustion engines are less efficient than typical fuel-based power plants
3. Efficiency of electric transmission, batteries, motors, regenerative breaking (much more important in slow-speed city stop-and-go driving than high speed freeway driving; granted, hybrid electric vehicles can also have regenerative breaking) lack of maintenance costs, VS. efficiency of mechanical transmission
Rod, there’s no debate about that. You assert it as your belief, people try to explain the physics, you repeat your belief. It’s a hobbyhorse.
Hansen’s name is perhaps the most strongly aligned in the public’s eye with the AGW hypothesis, and he supports nuclear power as part of the solution. He’s not alone, either.
david_a (222) — The big regional issue is precipitation changes in the next 40+ years. I found a regional study for Argentina, but just read thoroughly the section on Patagonia. Incidently, the study mentioned that central Chile, the farm belt of Chile, is going to become dryer. So is most of Patagonia, continuing the trend in precipitation during the 20th century.
I’ve seen mention of predictions for the countries bordering the Mediterranian Sea, the Middle East and Eastern Europe: drier.
Re 222 –
energy:
I suspect nuclear is safer than some would suggest (long term geologic storage, carefully managed, perhaps could be turned into a safe geothermal resource (I’m betting civilization does survive tens of thousands of years and more – that’s particularly where I’m still an optimist); Chernobyl was a bad design and poorly managed (political pressures to make it do what it was not ready to do); some incidents and risks (rusting out in Ohio; terrorism threat of on site waste (similar issues with chemical industry)) wouldn’t happen or would be reduced if political interests were better aligned with public interests), but is more dirty and dangerous than others would admit to (terrorism issues with breeder reactors? – presumably there are solutions, but … costs of safety (why are there political pressures to let things go?), waste has to be transported to long term geological storage, and as with coal, nuclear also has mining issues).
Solar cells are expensive but not to the point that they don’t make economic sense – particularly if there is to be an emissions tax.
Some waste and mining issues could also be involved (but I think solar technology has a smaller mining footprint and much smaller carbon footprint than coal, for energy produced – see below), although there will also be solutions – the effective energy per unit mass is much higher for solar cells than coal or oil or gas, so if waste and pollution were proportional to mass (??)
—
(if one considers the mass of just the photovoltaic material, then the ratio of energy per unit mass of solar to fossil fuel is very very large. Based on a sampling of commercially available modules, with equivalent lifetime at rated power (divided by 5 for perhaps more typical average power under 200 W/m2 time averaged insolation) 2.4 times warranty (warranty generally 25 years) going by medians and averages, respectively, the mass per square meter is about 12.7 kg, the energy per unit mass is about 3.5 or 3.1 GJ/kg, which is, for 40% efficient power plants, 267 or 239 times coal, 202 or 180 times oil, and 156 or 140 times natural gas (assuming it is accurately characterized by methane energy density) – by volumes (of solar modules, etc.), the energy density is 48 or 44 times coal, 61 or 57 times oil, and 62,000 or 57,000 times natural gas (but that can be reduced by compression of gas, of course) – this says something about how the costs of shipping and handling might compare; Considering the energy density using the mass of the photovoltaic material itself, this increases by a factor of about 12 (relative to module mass) for conventional silicon wafers (which had to be a certain thickness for mechanical stability in manufacturing), but could be increased by more for other (poly)crystalline Si methods that can make thinner layers – perhaps to 100 or more (180 ?) times the whole module value if total-internal reflection is used with diffuse back reflection to reduce the necessary thickness of the layer used to absorb the photons – and that or even greater values relative to above median,average modules for amorphous Si and other thin film materials (higher absorption for a given thickness because they are direct-band gap semiconductors (it’s a solid-state physics thing).)
—
, pollution control costs wouldn’t be so bad (would that also apply to nuclear?); some solar cells could be considered ways to reduce pollution by storing otherwise toxic material in a safer form (CdTe and other Cd based solar cells – Cd is a byproduct of zinc mining (or mining and processing?); Te can be taken from byproducts of the Cu industry).
Costs? From the sampling above (for rated power), median and average costs per peak W were $5.26 and $6.34. I would think that increased module size and large scale applications might bring that down to $4 – as that has been the cost per peak W I’ve been familiar with since sometime before the year 2000.
The median and average cost of solar electricity averaged over lifetime (see above) were 5.0 and 7.8 cents per kWh. Okay, that doesn’t include balance of system (installation/mounting, inverters) or financing over time (but consider the ‘demand’ for retirement investments – invest in solar cells, they pay back over time, problem solved? – and of course there’s renting… – aside from insurance for weather, etc, this is a very low risk investment – based on physics more than predictions of human behavior, aside from the prediction that humans will continue to demand electricity).
Continuing gains in experience, plus increased mass production, will reduce R&D costs and bring down costs. R&D for better materials, designs, and manufacturing methods can also lower costs (reducing thickness of layers by light-trapping, or using bulk heterojunctions, or other more complex topologies of the p-n junction, to reduce recombination of electron-hole pairs; nanostructures to convert higher energy photons into multiple electron-hole pairs).
I’ve heard that First Solar is/will be producing CdTe-based cells for $1/peak W, which, for similar life spans, suggests an electricity price of around 1 cent/kWh.
The costs of modules (median,average) in the sample were $609, $628 per square meter, $47, $50 per kg. Electronic-grade crystalline Si might be around $50 per kg (it was about $25 per kg a few years ago, and solar-grade material can be made for less), so I’m guessing about 1/20 of the module cost is for photovoltaic material (following numbers can be adjusted if that is wrong); A layer of CdTe might only need be a few microns thick; not sure of density but I would guess on the order of magnitude of 10 g/cm3, so the CdTe mass per area may be about 1/360 of the mass of the sampled modules, … well, the point is some very expensive materials can be used in thin film solar cells; I’ve heard there might not be enough recoverable Te (one of the rarest of the rare) from Cu byproducts but there may be enough for 100 to 200 GW (forgot whether that’s power capacity or power supply (1/5 of capacity?) and surely as demand for Cu increases (developing countries), the Te supply will also increase…
Other more common materials for solar cells (while rarer materials might be used for some electrical contacts, dopants, photosensitizers…): TiO2, oxides and/or sulfides of Fe, Cu, Zn, Ti, Ni, V, Cr, Ce, etc… And rarer but not as rare as Te so far as I know – GaAs, and combinations of Ga, As, In, Sb, etc…
FROM:
“Engineering Silicon Solar Cells to Make Photovoltaic Power Affordable” Steven Ashley –
http://www.sciam.com/article.cfm?id=engineering-silicon-solar-cells
“Specifically, he has raised the conversion efficiency of test cells made from multicrystalline silicon from the typical 15.5 percent to nearly 20 percent—on par with pricier single-crystal silicon cells. Such improvements could bring the cost of PV power down from the current $1.90 to $2.10 per watt to $1.65 per watt. With additional tweaks, Sachs anticipates creating within four years solar cells that can produce juice at a dollar per watt, a feat that would make electricity from the sun competitive with that from coal-burning power plants.”
And I haven’t even gone into geometric concentration, luminescent concentrators, solar thermal …
It may be possible to increase solar infrastructure more rapidly than nuclear.
Re 222 – At least in the transient response (as opposed to equilibrium), it is expected that warming will be greater in the Northern Hemisphere, especially at higher latitudes because of albedo feedbacks, but in general because of the greater land area – minimal warming will occur in Southern midlatitudes because of the dominance of water, and also because of a ring of upwelling water (it takes considerable time for the warming of upper oceanic water to partly fill the deep ocean and come back up in areas of upwelling deep water) – this upwelling is driven by winds from storm activity that will tend to be enhanced when there is greater warming equatorward. There is also the near-term stability of much of Antarctic ice, compared to short-term vulnerability of Arctic sea ice. Antarctic sea ice may also be less vulnerable to initial warming because of the influence of salinity on the freezing point (I might have this flipped around but I think less freezing has freshenned the water so that there is less melting – or more melting has freshenned the water so that there is more freezing?? – it’s complicated but quite interesting. The same underlying physics applies everywhere but some of the same conditions don’t apply to the Arctic…)
Re 222 – the albedo feedbacks being stronger at higher latitudes in general applies to the equilibrium as well as transient climate response, except for the timing of albedo responses.
Much of the importance of climate change is in spatial and temporal redistributions of precipitation and evaporation.
Re 224 – emission can be expressed in terms of optical properties relative to a blackbody, and it is convenient to do so because with increasing thicknesses of layers, assuming local thermodynamic equilibrium, radiant fluxes approach the blackbody values and never exceed them.
“radiant fluxes approach the blackbody values and never exceed them.”
(or if they exceed blackbody values for a local temperature, it is only because some radiation is reaching that location from another location with a higher temperature)
Two ways to illustrate this:
1. Build a chamber with a large internal volume and a small openning (a box with a small hole cut into one side). Whatever the optical properties are, there is, at any given wavelength, some emissivity and some absorptivity that are the same at local thermodynamic equilibrium. 1 – absorptivity = reflectivity. Let Ibb be the intensity (I) of blackbody radiation at some wavelength and temperature. Let all the walls be the same temperature. Start tracing the intensity of radiation at some wavelength along a path that reflects (or scatters if the surface is rough). Start with intensity I0. After the first reflection or scattering, the intensity I1 = I0*(1-absorptivity) + Ibb*emissivity. If absorptivity = emissivity, then, even if emissivity is a function of angle of incidence, after many many scatterings or reflections, the intensity along the path approaches Ibb. If the size of the hole is very small compared to the size of the box, than paths going into the box will scatter many many times before coming out of the box, so the intensity of radiation coming out of the box will be close to blackbody radiation intensity; the hole acts like a blackbody. If the inner surfaces are very reflective – so long as they are not perfectly reflective, it is only necessary to shrink the size of the hole to make the hole act like more like a blackbody.
2.
Imagine how the intensity of radiation in one direction along a path changes along a path. Assuming no scattering or reflection, through each infinitesimal layer, the fraction that is absorbed is equal to the fraction of blackbody radiation intensity that is emitted. Thus over distance, the intensity approaches a blackbody value. If there is scattering and/or reflection, then the intensity approaches a blackbody value if radiation scattered into the path was originally emitted from layers with the same temperature (consider the box above). For a gas or typical cloud, scattering, emission, and absorption cross sections of molecules and particles tend to be the same in all directions (except ice crystals that have preferred orientations as they fall… you get the idea)… but even when they aren’t, these methods can be applied.
http://www.terradaily.com/reports/China_says_US_could_hold_up_climate_deal_999.html
Excerpt:
by Staff Writers
Washington (AFP) March 18, 2009
China pressed Wednesday for the US Congress to pass legislation to fight global warming, warning that inaction could hold up a new treaty slated for Copenhagen in December.
China’s chief climate negotiator Xie Zhenhua held talks in Washington with the administration of President Barack Obama, who has vowed action to slow the planet’s warming in a sharp reversal from his predecessor George W. Bush.
A UN-led conference in the Danish capital in December is meant to approve a new global warming treaty for the period after 2012, when the Kyoto Protocol’s obligations to cut carbon emissions expire.
But Xie said China — by many measures now the world’s biggest emitter — was still waiting to see rich nations’ commitments before putting its own ideas on the negotiating table.
“The difficulty in reaching an accord is how can we reach the mid-term goals,” Xie said.
“Canada has not yet issued emission figures to meet its commitments. The United States is in the same boat — there is just talk but no action,” he told the Carnegie Endowment for International Peace.
“The key point is whether Congress will pass a bill or not,” Xie said.
Xie said that China was also waiting for rich nations to provide funding and technology to fight climate change.
“Once these prerequisites are realized, then I believe China will move aggressively,” Xie said.
China has already launched a drive to improve energy efficiency. The Kyoto Protocol makes no demands of developing nations — a sticking point that led Bush to shun the treaty….
#233
Worse than spoiled brats arguing over who’s going to ride the bike and who’s going to walk.
All the makings for a sick soap opera — “As the World Warms”.
Jim Bullis, regarding your posts 199 and 217: Part I
Perhaps I didn’t understand your posts, but you seem to be concluding that switching a significant portion of the auto fleet to PHEV or electric vehicles, would end up emitting more carbon per mile driven, than the current auto fleet, especially if the current fleet switches to hybrids.
I reached a different conclusion, particularly with the current fleet with reasonable hybrid penetration, and I would argue especially in a state like California. I pointed out that a significant portion of the energy extracted from crude oil is consumed prior to ending up with gasoline. Lets quote your own source material.
“But don’t jump to conclusions: The full analysis needs to be done on a “well to wheels” basis. That’s because the fuel for the car must be pumped from the ground, transported, refined, and transported again to the filling station—steps that add about a third more CO2. And you also need to consider how much carbon dioxide would come from plugging a car into your local grid, with its particular mix of generating technologies.”
Please note that is what I pointed out my post… producing, moving, refinining, and distributing, eats up a lot of the energy in crude oil. This is especially true for heavy crudes, or crude oil from secondary or tertiary oil recovery, or tar sands, or oil from foreign countries moved long distance, especially if gas is flared as a result. This pretty much describes the oil supply for California, for example.
Lets look at a second quote from your source:
“Consider a plug-in hybrid that runs half its distance on gasoline and half on electricity derived from an advanced combined-cycle power plant fired by natural gas, for example. Such a car would reduce greenhouse-gas emissions by about 25 percent with respect to the well-to-wheels emissions of a conventional hybrid. Charging that same plug-in using electricity from nuclear power or renewables cuts CO2 emissions almost in half, because the carbon dioxide emissions involved with nuclear energy (mostly from mining) are minimal and are essentially undetectable for hydroelectric power. But if you run that plug-in with electricity from a typical coal-fired power plant, it now releases from 4 to 11 percent more greenhouse gases than a conventional hybrid would.
So how green is your grid—or, more accurately, how carbon intensive is your supply of electricity? In the United States, the three cleanest states—at well below 200 grams of CO2 per kWh—are Idaho, Washington, and Oregon, due to their extremely high percentage of hydroelectric generation. The worst—at just over 1000 g/kWh—are North Dakota and Wyoming, which use large amounts of coal. California, the state that buys the most Priuses, comes in at roughly 450 g/kWh, about 25 percent better than the U.S. average. Be aware, though, that much electricity crosses state lines.”
It says right in this article, that the PHEV reduces carbon emissions 25% from combined cycle plants, and most fossil fuel plants in California are either combined cycle or cogen, so this is close what we would expect there from existing grid supply. The savings of PHEV is 50% if entirely from renewables, and only if the electricity comes entirely from coal, does the carbon emissions end up higher by about 4-11%. This is an unrealistic assumption, particularly for California. They have a goal to hit 20% renewables on the grid by 2010, which the Governor says should be easy. The target for 2020 is expected to be 33%. And note that none of the electricity consumed in California can be coal sourced.
So switching to PHEVs should reduce the carbon emissions by somewhere in the range of 30-40% over hybrids, and easily over 50% when compared to gasoline-IC vehicles.
Your own source supports what I posted.
Follow-up CdTe:
prelimary (further explanation to be posted later if time permits):
If there are 20,000 metric tons of Te reserves (based on recoverable Te from processing of Cu ore), that would be enough (in terms of annual average power supply, not capacity) about 35 GW of solar power – maybe 8 % of current U.S. electricity supply, but not Earth-shattering. $500 per kg of CdTe translates into about a tenth of a cent per kWh.
On the other hand, might the reserves be more like 40,000 or 80,000 metric tons (16 or 32 % of U.S. electric power – not to imply this all goes to the U.S., of course, just using U.S. electric power for comparison)?
If the Te/Cu ratio in ore is 1/10,000, and if $1/kg Cu is the no-profit price for Cu, then an additional Te price of $10,000 /kg could drive the supply of Cu (rather then the demand for Cu driving the supply of Te). This price would add 2 cents /kWh to the solar electricity price (equivalent 60 year life span at rated power, before interest rates, etc.).
Se is not as rare as Te.
How much Te,Se,Cd,In,Sb,Ge,Ga,As… is in coal ash?
Many of the more common elements in the Earth’s crust that could be used in oxide/sulfide solar cells (Cu, Ni, Zn, I think Cr, Ce, V …) are present in average rocks at concentrations on the order of 100 ppm (Ti,Mn,and Fe more abundant). If necessary, the energy of mining common rock for such materials might (?) be payed back in under a year (if memory serves – this was based on some back-of-the-envelope stuff; just wanted to put the concept out there) in under a year, and recycling solar cells makes this a once in a thousand+ year cost. Top-of-the-line deluxe high-efficiency solar cells could be used in concentrated sunlight.
———-
Of course the cheapest form of solar energy is daylighting (assuming affordable thermally-insulating windows/skylights available (silica aerogel?)). Windows with coatings or screens to reflect UV and solar IR, or luminescent concentrators to convert those wavelengths partly to electricity, or using transparent solar water heaters that absorb those wavelengths, or using poleward-facing skylights (blue sky light is depleted in solar IR) would boost the ‘efficiency’ of the lighting (closer to 100% visible, so less waste heat in summer) Rooftop PV modules could also be cooled by water, thus heating water. Don’t forget heat exchangers and heat pumps. Etc.
> 233, 234
Er, Ron? Did you get as far as the last paragraph there?
> How much … is in coal ash?
teh goog
http://pubs.usgs.gov/bul/b2144/33_tables/table1.htm
Patrick 027, I was just trying to assist with the discussion of radiation exchange between bodies of different temperatures. The thought that vibration emission derives from a different mechanism and not directly a function of temperature like “Planck type” emission aids that discussion — much in the same ballpark as BPL’s reference in 218. I do realize, however, that Planck blackbody analysis is a convenient and the predominate construct used in analyzing that emission, even though the emission is physically generated differently. As BPL implied, once emitted, photons are all characteristically alike: ones from CO2 vibration will scatter, absorb, reflect exactly the same as photons with the same energy from a pure blackbody.
Ok. Now that the article about UHI has been dismissed a few times, somebody at least answer me this. They found a substantial urban heat bias. It accounted for forty percent of the warming observed. The magnitude of the urban warming was twenty times larger than the value posited by the IPCC. This seems very serious, even if it happens to be just a local effect (local meaning all of of China, of course). Why should this not be examined further? Why shouldn’t we do a similar study here in the US and at the other ground temperature stations? Why dismiss this important data as irrelevant? Instead of guessing and assuming that China’s cities are different from all others in the world, why not look in to it?
Chris — it HAS been done in the US. Check these out:
Hansen, J., Ruedy, R., Sato, M., Imhoff, M., Lawrence, W., Easterling, D., Peterson, T., and Karl, T. 2001. “A closer look at United States and global surface temperature change.” J. Geophys. Res. 106, 23947–23963.
Peterson, Thomas C. 2003. “Assessment of Urban Versus Rural In Situ Surface Temperatures in the Contiguous United States: No Difference Found.” J. Clim. 16(18), 2941-2959.
Peterson T., Gallo K., Lawrimore J., Owen T., Huang A., McKittrick D. 1999. “Global rural temperature trends.” Geophys. Res. Lett. 26(3), 329.
Note the title of the second entry.
Re #222,
Yes I think nuclear has got a undeserved bad rep in some parts, Lovelock said as much a few years ago. Nuclear would also benifit from carbon having an associated cost.
Shell are putting their money into bio-fules and carbon capture (both big pay-out long shots). They have still got considerable solar and wind assets they have just stopped growing them. To me this indicates a 5yr ‘buy a lottery ticket and do-nothing’ plan that will get them over the carbon market uncertainty.
When you look at some of their marketing stuff they make it clear that they belive there were 2 senarios, “Design” and “Scramble”. The senarios include GW and peak oil and look at the next couple of decades depending on how well politicians plan and follow through with regulation. IMHO by dropping solar and wind they are acting as per “scramble”, ie: they believe a sound carbon market is a slow train arriving.
OTOH maybe it’s just not in line with their “design” but if that’s the case then how does it explain the other companies and groups in the linked story below.
There was also a story in the Age today about Australia’s proposed ETS. It would seem virtual all bussiness and union groups want a price on carbon (except the coal industry). The article also has a good list of market uncertainties at the end.
Seems to me industry have been waiting around for 5+yrs for details on the carbon price/market and are now getting tough with a demand for some form of certainty so they can plan for the next X decades.
Rod B. #224: Horsepuckey from beginning to end. Propose a mechanism by which CO2 will absorb or emit radiation radiation that is not associated with quantum transitions–e.g. vibration, etc. Remember, we are talking about molecules, not ions or free electrons here–molecules. Please, enlighten me on this new physics. Or go back and learn the phsyics as it really is. That would be another alternative.
“One of the more curious aspects of the AGW issue is those most strongly aligned with the hypothesis seem to be the most antagonistic to what is obviously the most practical mediation.” – david_a
No, nuclear is not “obviously” the most practical mediation. Short-term, improved energy efficiency and demand reduction offer much faster reduction in emissions, as do protection of tropical forests and a switch away from meat- and dairy-heavy diets. Longer-term, according to the IPCC (AR4, report of WGIII), nuclear has a role, but it is a relatively minor one compared to efficiency, renewables, and CCS.
David A, I’m afraid I have to agree with Nick on this one. Despite the fact that I am generally a supporter of nuclear energy, in the near term we can’t build our way out of this crisis. Conservation is the only way forward in the immediate future. Renewables certainly offer considerable scope for relief in the mid-term. I don’t think we can take nuclear power off the table–it may well be needed. However, we do not do the case for nuclear power any favors by sweeping the problems it poses under a rug. Nuclear waste doesn’t have a solution yet, and proliferation remains an issue. I am confident these problems can be managed, but the way forward for nuclear power is to find solutions to these problems, not to merely assert confidently that it is the way forward.
Ray (242), I’m confused: I think that is what I said. Or, enlighten me on your assertion.
To me it’s really simple. You store the nuclear waste where the power is being used. It takes a multi-thousand year commitment, and people aren’t likely to stand by that commitment if the waste is off in some depopulated desert in Nevada.
In other words, put the waste in New York City, LA, Dallas, etc. They want the power, and they’ll be highly motivated to keep it properly contained for thousands of years. If they don’t like that, then they didn’t really want the power in the first place. They just thought they did.
RodB, this bit:
“is that the IR emitted radiation from the vibration energy of CO2 molecules is not the same mechanism that generates the so-called blackbody”
is incorrect. Ray didn’t explain well his problem with it.
CO2 molecules are not alone. They are in a sea of other molecules and this is rather similar to the state solids are in, except the binding energies are much higher. Yet you seem DETERMINED to say that although solids can accept CO2 emission spectra and thermalise it (even if it’s solid CO2) yet gaseous forms cannot.
THIS
IS
WRONG
If anything, the binding energies of a solid being higher will remove the motion of the constituents from being a sink of energy and a method of thermal equilibrium being attained. A gas has much greater freedom to use this sink to repartition energy.
And where it comes from makes absolutely no difference to this sink.
You are completely, utterly and in all ways wrong on this.
Rod, you are implying there is some controversy over the nature of blackbody radiation. There isn’t. It is well understood, and has been since 1900. It may not be resolved in your mind, but blackbody is simply the energy distribution the pertains when the radiation field is in thermal equilibrium (both with itself and its surroundings).
Ray Ladbury Says (23 March 2009 at 9:06 AM):
“…and proliferation remains an issue.”
Forgive a brief (I hope!) digression into geopolitics, but I fail to see why proliferation should be an issue, since it’s been amply demonstrated that countries which want nuclear weapons can develop them without first developing nuclear power generation. So why should the rest of the world refuse to use nuclear power in order to prevent proliferation that has happened anyway?
#182 Triana/DISCOVR Satellite
The stimulus bill passed by Congress contains a $9 million item for NASA to de-mothball and launch the satellite ASAP – “on a priority basis”.
I suspect the reason Bush-Cheney didn’t launch is the data would have shown global warming so unambiguously action would have had to be taken, in spite of the fossil fuel industry’s power. I’ve a hunch that’s why some Republicans ridiculed it as “Goresat”. JMO
Whatever the reason, we would have 8 years of data, and it would show the dirtying of the skies.
Note: Today is a CLEAR, BRIGHT BLUE Sky in the Northeast — no clouds or contrails anywhere. Run out and look at it, that’s the way a lot of days used to be. It has gotten worse in the last 3 years. I suspect the Asian Brown Cloud, possibly increase in jet travel is a factor. China is bringing 1 new coal-fired plant on line every week — I’d guess this is the major source. It may be emitted from Asia but it’s over my head.
In 2007 I traveled by jet west to Cleveland. The plane passed through a brown layer of air; looking down from above it, I saw the ground looking hazier and browner.
I’ve no guess whether the increase in air pollutions will warm or cool or plateau the average global temperature. I worry that if the smog results in a temporary cooling or plateau that the deniers and stallers will use to justify no action on AGW.