Transportation! What do I win? 
A new SUV - 1.5 MPG
Indeed, the CEI [Competitive Enterprise Institute] and the National Review obviously has a strong point-of-view in this debate. As for electricity generation in France, this is true as far as I know, but there are a few things to note:
(1) the reason that France has gone the nuclear route is not because nuclear power is cheaper to produce in France (studies have shown that its not) but that producing electricity via fossil fuels is more expensive there. And, this is at least in part because they haven’t subsidized fossil fuels like we have (and have more heavily taxed them to account for the externalized costs).
(2) the fact that France already produces a lot from nuclear is a mixed blessing as far as Kyoto is concerned because they have to make cuts based on what their 1990 emissions were. They have less ability than we do to make those cuts in the electricity sector since their electricity sector already emits so much less in greenhouse gas emissions.
In fact, while the article emphasizes the way in which Kyoto might be easier for these selected countries, it does not mention the ways in which Kyoto might be easier for us. And, one of the big ways is that the Europeans already use fossil fuel energy more efficiently, partly because they tax it more heavily to better reflect the externalized costs. They don’t have lots of people driving around in big honking SUVs getting 15 mpg.
At any rate, this is all pretty much beside the point because Kyoto is not on the political agenda in the U.S. anymore. What is on the agenda is the McCain Lieberman climate stewardship act and its emission targets are considerably more modest than the Kyoto ones. (Instead of cutting back to like 5 or 6% below 1990 levels by 2010-2012 as in Kyoto, it requires cutting back to year 2000 levels in 2010 and keeping the cap there. And, 2000 levels are something like 14% above 1990 levels. It is a flexible cap-and-trade approach and also has similar flexible provisions for carbon sequestration and the like as Kyoto.) Of course, CEI (and the Bush Administration) don’t like this either because their concern isn’t really whether these other nations are getting an easier deal than us or not. They simply don’t want to start regulating greenhouse gas emissions, even in a flexible cap-and-trade manner, at all. This is partly a matter of political philosophy and partly a matter of the considerable pull that the coal, electric power, and oil industries have with them.
The EPA status report on U.S. emissions had all this info in it. I can’t remember the numbers off the top of my head but the big take-home point is that there is a fairly even distribution between transportation, industry, and residential use. It is not like any one of these sectors is dwarfed by the others and doesn’t really matter…They all make significant contributions.
You’re welcome, duffer. There are pluses and minuses to simplifying complex subjects, but I’m happy if in this case you were helped by it.
To your question:
Ignoring for now whatever contributions there may have been through time from cosmic sources, we can assume that the overall amount of carbon present on and within the Earth has remained steady through time, presently estimated at 1 x 10[sup]23[/sup] grams (roughly 1.1 x 10[sup]17[/sup] tons). That carbon could be in a number of forms at any given point in time - pure inorganic forms such as graphite or diamond, organic or inorganicly-derived methane, carbon dioxide gas, living organic material or lithified organic matter (coal), as part of biogenic mineral deposits (coral reefs) or inorganic mineral deposits (gypsum salts)… there are others, but I think you get the idea. The bulk of that 10[sup]23[/sup] grams of carbon - 8.06 x 10[sup]22[/sup] grams, or 80.6% of total carbon - is buried in sedimentary rocks (organic and inorganic), and not active in the short-term biological carbon cycle.
On geologic time scales, nothing that is buried is guaranteed to stay forever buried, because plate tectonics will keep shuffling things around. Limestone and coal deposits can eventually be subducted into the Earth’s mantle, where their constituent bits are melted and combined with other elements and compounds. The carbon from those sources can be incorporated into other minerals, or else released back into the atmosphere through volcanic outgassing, where it’s once again free to have an effect on the short-term biological carbon cycle. And ultimately, some of that carbon will become incorporated into a swamp or coral reef that will become buried and cut off again from interacting with the biosphere. That cycle does repeat itself over and over, and has for a good chunk of Earth history.
But it IS a long-term cycle, by which I mean that shifting carbon to and from the otherwise non-reactive rock reservoir naturally happens over the course of millions of years. By burning fossil fuels, we are accelerating the rate at which carbon is transferred out of the rock reservoir to the biosphere, but there is no compensating mechanism (by natural means, or practical artificial methods) to take that “extra” carbon back out of circulation equally quickly. That is where the imbalance in the short-term biological carbon cycle is introduced, and where the problem lies for living organisms that have evolved to survive in a biosphere with a particular balance of carbon sources and sinks.
(Btw, AFAIK the Pope never had any problem with any of this. 
)
Well, okay, if you look over long enough time scales, it may be true that some sort of long-time equilibrium value of CO2 concentrations will be reached (although this is far from clear…It might continue to bounce around). And, indeed, the CO2 that we are emitting into the atmosphere won’t remain there forever. In fact, I saw a graph somewhere that showed predictions of how CO2 would vary over the next 1000 years according to various emissions scenarios. The problem is that the sort of timescale over which the balance will re-adjust and the CO2 in the atmosphere will fall back to near pre-industrial levels even if we stopped all emissions today is on the order of hundreds of years (maybe even up to a thousand years or more…and of course it depends exactly on what one means by “near pre-industrial levels”).
So, yes, in some sense in the “long run” our emissions won’t matter (assuming that they stop eventually…which they must because we’ll run out of these carbon stores). But, as Keynes says, in the long run we’re all dead. This is a long enough lived transient that we are talking about that it will have a significant effect on the earth’s climate and therefore on us and on various ecological systems…And, of course, the long-term changes it causes to human civilization and the global ecology may long outlive the time when the CO2 concentrations are actually high.
As for whether the carbon was “meant to stay buried”, well, phrased this way what you have is really a philosophical question. However, I think is the important and more easily answered question is whether our unburial of it over a very short timescale in geological terms will likely cause considerable shifts in climate and result in significant problems for ecological and human systems trying to adjust to this shift. And, the answer to that is “yes”.
It looks like sunfish said most of what I said, only with more detail, and much better in his simul-post.
No worries, jshore. You’ve been doing a marvelous job presenting a ton of other material in this thread - that makes it easy for me to parachute in with the odd comment.
Btw, I’m a she. 
Thanks, sunfish. It’s nice to have an expert in the field to answer some of the tougher questions rather than a poser like me. [We physicists like to pretend that we’re experts in all fields of course. ]
Whoops…My bad. They need a little gender icon next to the poster’s name. or English needs some gender-neutral pronouns / possessives (although I guess “his/her” works in a pinch)!
But why is CO2 so important? And does the fact that we are generating all that heat (with cars, heaters, factories etc) play any role in global warming?
Lol, jshore, I’m not a global warming expert by any stretch, but having a carbon cycle disciple on my grad school advisory committee surely provided some encouragement to learn it when qualifying exams rolled around. Anyway, since, as you say, all physicists are all-knowing (except for your not being able to magically ascertain that I’m not a guy), there’s no reason to call yourself a poser here.
To understand why CO2 is important, you need to understand what role an atmosphere plays in warming the surface of a planet in the first place. This page has a nice summary of the greenhouse effect, which generally speaking refers to the ability of a variety of gases to trap the heat of the sun at the Earth’s surface. Although water vapor is the most abundant greenhouse gas in our atmosphere, CO2 is the focus of most discussion because that gas is arguably the one that we have the most control over.
The heat generated by activities in cities is referred to as the urban island heat effect, and it can have some localized influence on weather. It doesn’t contribute significantly to the overall warming of the planet, however.
To answer the second question first: No, the actual heat generation is pretty much insignificant besides which I think it will tend to get radiated away into space. What is much more significant is when you change the energy balance by increasing the amount of the sun’s energy that gets retained as opposed to re-radiated, which is where the “greenhouse effect” comes in (although a better analogy in some ways than a “greenhouse” is said to be a “blanket”).
As for the second question: Well, CO2 is the most important, but not the only important greenhouse gas. I think the Kyoto Protocol regulates something like 6 greenhouse gases. CO2 is the most important contributor because of the combination of its potency as a greenhouse gas (i.e., in having the atmosphere retain more of the heat re-radiated from the earth), the amount that we emit, and the length of time it takes for this CO2 to be taken back out of the atmosphere. Methane is in second place…It is actually much more potent as a greenhouse gas molecule for molecule, I believe, but we emit much less of it.
Some contrarians like to point out that water vapor present in the atmosphere is a larger contributor to the greenhouse effect than CO2 is. (This being the total greenhouse effect, without which our planet would be something like 30 C ? colder and thus quite inhospitable.) However, this statement, although true, can be (and is often purposely used to be) somewhat deceptive in its implications regarding anthropogenic (human-caused) warming. The reason is that we humans cannot directly effect the amount of water vapor in the air very much. This is both because our contribution is fairly small in relation to other sources and because the water cycle tends to equilibrate fairly fast…i.e., it gets rained out. So, we don’t have to worry about the water vapor that we emit into the atmosphere causing global changes in climate (at least at current levels…I don’t know what sort of increase we could tolerate…5X, 10X, 100X, … before it would become a significant issue).
However, water vapor does play an important indirect effect in the anthropogenic global warming. It works like this: As we put the long-lived greenhouse gases like CO2 into the atmosphere and heat things up, more evaporation occurs so that the average concentration of water vapor in the atmosphere increases. Because of water vapor’s greenhouse effect, this then leads to further warming. It is what is called a “positive feedback” and it is believed to multiply the direct warming effect of the CO2 by something like a factor of 3. The role of water vapor is complicated because it can also condense and form clouds which can having a cooling effect (by reflecting sunlight) but also a warming effect (by reflecting heat re-radiated from the earth). In fact, much of the uncertainty in the magnitude of the expected anthropogenic warming is due to uncertainties in the water vapor and cloud feedback mechanisms.
Oh, by the way, one last thing in addition to greenhouse gases is the contribution of black aerosol (soot) particles. These can cause warming in the atmosphere by absorbing more sunlight (and re-radiated heat from the earth?). But, they can also cause warming and faster melting of the glaciers by lowering the reflectivity of the snow and ice on them. The importance of this contribution is also currently the subject of much research.
All true!
Posing physicist #2.
Nice discussion. A few points:
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It’s important to note that global warming deals with overall climate, not with specific weather. The impact of this is counterintuitive: more heat means more evaporation and more energy in the global thermoenergetic system, the latter translating to more wind – more water vapor in the atmosphere and more wind translates to more storms – which can have a net cooling effect on a particular location’s local climate.
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Do not forget that a major mode of heating homes and businesses throughout Europe and the American seaboard in the 1700s was the burning of coal in individual fireplaces and stoves. (Una may have some statistics on historical home heating here.) So yes, anthropogenetic CO2 could well exceed natural CO2 output even at the beginning of the Industrial Revolution – because you do other things with fossil fuels than modern industrial technology tends to use them for.
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Distinguish between scare stories of the long-range impacts of global warming and the reality of what has been observed and documented with peer review. You need not buy into the idea that the world will be an overheated arid desert by 2150 to accept that there’s more energy in the planetary heat engine due to the greenhouse effect, with the consequences that can reasonably be deduced from that.
Lest we forget a few points on the warming of the atmosphere:
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The Stefan-Boltzmann equation predicts the warming of a black-body proportional to the fourth power of atmospheric pressure. The caveat with using this equation is that Earth is hardly a black body, but rather a continuous layering of gases with different absoption constants. We can conclude from this condition and the Stefan-Boltzmann equation that the globe is going to heat dramatically with only a slight increase in the properties of any of these layers–with the most influence coming in the troposphere.
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A few words on the oft-cited equilibrium in this thread: It seems to me that the behavior of the atmosphere in response to carbon dioxide concentration, temperature, etc., is harmonic; I suppose we could kick these curves into a Fourier transform to find out. Either way, the fact that these curves oscillate over time [and the fact that 100 years is a very small time in comparison to the period of these oscillations] might point us to the fact that the rise in temperature on Earth is normal. Of course it’s not, you say. Consider this: with every degree change in temperature, we lose a certain volume of ice in the form of glaciers. This ice raises the volume of the oceans, but also increases the surface area over which the ocean can dissolve gases. Because the atmosphere is heating, carbon dioxide will less readily dissolve into the ocean, but an increase in surface area will reverse this action.
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The equilibrium also points a finger at the source of carbon dioxide on the planet. It’s true that we have released more than our share of carbon dioxide into the atmosphere in the time since the Industrial Revolution, but we have to consider the change in our use of fossil fuels in our every day lives. Because formation of fossil fuels requires a long period of time under subterranean pressures and temperatures for a large amount of standing organic matter, the amount of fossil fuels available to humanity is diminishing at an alarming rate. That fact, combined with the fact that an increase in pollution due to the use of fossil fuels makes life generally crumby [see: Manchester, England, at the end of the eighteenth century], indicates that our use of fossil fuels must stabilize sometime over the next century.
Global warming does exist, and it exists as a necessary condition of the evolution of the Earth. While it seems that people are disproportionately influencing the warming of the Earth, our influence is only a small anomaly in the oscillation of the atmosphere. This anomaly will disappear once economics necessitates that it changes.
Entropy at Work: First, welcome to the SDMB.
As for your point 2. about equilibrium / harmonic behavior: There has been a lot of thought in the scientific community concerning feedbacks in the climate system. You have identified one possible negative feedback whereby increasing temperature might increase the re-uptake of CO2. This may occur to some degree…Perhaps sunfish will know more about the current thinking on some of these carbon cycle issues. However, my impression is that any such negative feedback effects increasing reuptake of CO2 are certainly not expected to be dramatic enough to stop or reverse the rise in CO2 and other greenhouse gases due to human emissions. And, in fact, there are some possible positive feedback scenarios…particularly involving the release of methane, which remain somewhat speculative. (Scientists are still trying to figure out exactly why CO2 and methane levels rose dramatically in the past when we went from Ice Age to interglacial. The triggering is believed to be the initially-modest warming induced by the changes in solar radiation due to orbital oscillations, which were then magnified by the release of these gases, but the exact mechanism that caused this release remains speculation, I believe. )
There are also some positive feedbacks that affect not CO2 concentrations but the temperature itself. For example, the melting of the ice and snow that you mentioned tends to reduce the reflectivity of sunlight in these areas, thus leading to more warming. Another one that I mentioned before is how the warming increases the amount of water vapor in the air which then leads to more warming. Some people have argued for negative feedbacks too. For example, Richard Lindzen has a hypothesis called the “iris effect” whereby the increase in water vapor leads to an increase in clouds in such a way that it produces a cooling that offsets most of the warming. However, this effect has not gained much acceptance in the scientific community…There is still uncertainty about the magnitude (or even the sign) of the feedback effect due to clouds, but few believe Lindzen is correct regarding its being a strong negative feedback. (It would also be hard to explain how the climate system has undergone such dramatic cycles in the past…e.g., the ice ages…if the climate system really had such strong negative feedbacks.)
As for the current rise in temperature, the best evidence from temperature proxies over the past 2000 years published by Michael Mann et al. at U.Va. is that there have been temperature oscillations in the past but that the current upkick is particularly dramatic and brings the temperatures in the Northern Hemisphere to their highest values during that time period. (For the Southern Hemisphere, the data are too sparse to make a definitive conclusion on whether this is the warmest its been in the last 2000 years or not.)
As for your third point, yes, eventually we will run out of fossil fuels. However, the calculations for how high the CO2 levels would have risen by that time are on the order of something like 4 or more times their pre-industrial levels if I remember correctly. (Strictly speaking, this level would also depend on the rate of burning the fuels; however, I don’t think this dependence is that strong over the sort of realistic ranges that one might contemplate.)
Actually, a reference for the numbers on how high CO2 concentrations would go if all the fossil fuels were burned is K. Hasselmann et al., “The Challenge of Long-Term Climate Change,” Science, Volume 302, p. 1923 (Dec 12, 2003). They give a range from 1200 to 4000 ppm, where the first number is derived from an estimate of “conventional resources” and the second from “conventional and exotic resources.” (The pre-industrial level is something like 280 ppm.)
Thanks. I’ll have to check that out.
FWIW, I appreciate all the info to my question. ** jshore ** and **sunfish ** especially.
I already accepted “global warming” as evidenced by the end of the Ice Age. What I was torqued about was the idea of SUV’s being the “end of the world” from the emissions they emit.
I would love to own a vehicle that spews absolutly no pollutants. Just ain’t gonna happen anytime soon. (Maybe get Soros, Gore and Heinz to subsidize?)
Seriously though, thanks for the info. When I can afford a hybrid that will tow my boat, I’ll be first in line.
I have heard tell of a new-fangled contraption called a ‘velocipede’ or some such nonsense. They say that one could use it for journeys of under, say, 5 miles in place of one’s horse and trap.
The problem there, my friend, is that the propulsive power for one of those devices tends to emit great quantities of waste heat while operating it. In addition, that motive source emits quantities of polluted water, technically termed “perspiration,” which evaporate and pollute the atmosphere. The recommended treatment for this “perspiration” is to immerse the motive source in water, which thereupon becomes itself polluted and is released into the environment. And many common fuels for this motive source, such as beans and beer, produce methane emissions polluted with ketones and other organic compounds, which are released into the atmosphere.