Naked Science Forum
Life Sciences => The Environment => Topic started by: _Stefan_ on 12/06/2007 12:39:06
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I read in the paper today that with hydrogen burning as an energy source, coal is used to make hydrogen from water, then the resultant CO2 is buried. I thought to myself that all our problems would instantly be solved if we continued burning fossil fuels the way they currently are, but the greenhouse gas emissions were collected and buried instead of released into the atmosphere. Forget 50% emission reduction by 2050, 100% reduction could take effect almost immediately!
Regarding car fuel emissions... cars could be fitted with a contraption that condensed the CO2 and H20 and held it on-board the car for disposal at a later stage.
Is my proposal valid?
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Burial of a gas isn't trivial.
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Hi Stefan
it's ideal in theory but almost impossible in practice.
The problem is that to scavenge and sequester carbon dioxide requires energy. This means that you will need to liberate even more carbon dioxide to deal with the stuff you've just produced.
The knock-on effect is that your engine or generating efficiency will fall dramatically.
There are some alternatives. One of the "clean coal" technologies being discussed is coal gasification. Hot steam is pumped into a seam where it reacts with the coal to produce "syngas", a mixture of hydrogen and carbon monoxide. These can be burned directly (obviously yielding some carbon dioxide), or the carbon monoxide can be removed and chemically sequestered and the hydrogen fed to a power station, the exhaust from which would be water.
There's nothing new about the chemistry, gas-works were producing "town-gas" like this over 100 years ago. But it's cleaner because you don't expend huge amounts of energy shovelling and blasting rock to get at the coal, and it makes small high-quality but low-yield seams more efficient to exploit.
The alternative approach is to build more nuclear stations; however I'm not sure, and perhaps someone can help me here, how much "embodied carbon dioxide" there is in a nuclear station. In other words, how many years must it run for before it becomes carbon neutral?
Chris
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Hi Stefan
I'm a little confused as to why we need to go to the expense of burying carbon dioxide when it has been proved that CO2 emissions produced by humans have no effect on the climate. The sea, volcanoes, animals and rotting vegetation produce more carbon dioxide than man ever could.
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Hi Stefan
I'm a little confused as to why we need to go to the expense of burying carbon dioxide when it has been proved that CO2 emissions produced by humans have no effect on the climate.
Please can you show me where and by whom this is proven? Scientifically.
The sea, volcanoes, animals and rotting vegetation produce more carbon dioxide than man ever could.
This may be true, but our emissions are not part of the "natural" cycle, and so add to the "positive" side of emissions, thereby causing an imbalance in the system. Just as you could have 2 houses balanced on a pair of finely tuned scales, it would not take much increase of mass on one side to tip the balance, and certainly only a tiny fraction of a percentage of the mass of the house. This analogy holds with the anthropogenic emissions, in that although ours are a small fraction of the total, they undeniably have an accumulative effect.
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Hi Stefan
I'm a little confused as to why we need to go to the expense of burying carbon dioxide when it has been proved that CO2 emissions produced by humans have no effect on the climate.
Please can you show me where and by whom this is proven? Scientifically.
I agree with your inference - we have lots of theories, but no proof either for or against.
The sea, volcanoes, animals and rotting vegetation produce more carbon dioxide than man ever could.
This may be true, but our emissions are not part of the "natural" cycle, and so add to the "positive" side of emissions, thereby causing an imbalance in the system. Just as you could have 2 houses balanced on a pair of finely tuned scales, it would not take much increase of mass on one side to tip the balance, and certainly only a tiny fraction of a percentage of the mass of the house. This analogy holds with the anthropogenic emissions, in that although ours are a small fraction of the total, they undeniably have an accumulative effect.
The notion of anything being "natural" or "unnatural" is meaningless. We are a part of nature, and to argue that CO2 produced by termites is more natural than CO2 produced by humans is a meaningless concept.
Nor is it as if one can say that humans have simply changed a historically constant situation, because the Environment (inluding CO2) has always been in flux, so there is no historic balance to change - it was always changing anyway, and we are merely a part of the present phase of change (whatever the impact we have on the Environment may be).
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Hi Stefan
I'm a little confused as to why we need to go to the expense of burying carbon dioxide when it has been proved that CO2 emissions produced by humans have no effect on the climate.
Please can you show me where and by whom this is proven? Scientifically.
I agree with your inference - we have lots of theories, but no proof either for or against.
I have yet to come across a single scientific evaluation of the “anti” lobby that has withstood testing. Most seems to be based on very local effects and incorrect interpretation of peer reviewed evaluations. Certainly, there are few instances where the “pro” lobby can state beyond a “p” value of 1% on an given scenario, but I have not seen anything from the “anti’s” that can’t be swiftly shown to be incorrect. The latest is the effect of the solar cycle on climate change.
The sea, volcanoes, animals and rotting vegetation produce more carbon dioxide than man ever could.
This may be true, but our emissions are not part of the "natural" cycle, and so add to the "positive" side of emissions, thereby causing an imbalance in the system. Just as you could have 2 houses balanced on a pair of finely tuned scales, it would not take much increase of mass on one side to tip the balance, and certainly only a tiny fraction of a percentage of the mass of the house. This analogy holds with the anthropogenic emissions, in that although ours are a small fraction of the total, they undeniably have an accumulative effect.
The notion of anything being "natural" or "unnatural" is meaningless. We are a part of nature, and to argue that CO2 produced by termites is more natural than CO2 produced by humans is a meaningless concept.
Nor is it as if one can say that humans have simply changed a historically constant situation, because the Environment (inluding CO2) has always been in flux, so there is no historic balance to change - it was always changing anyway, and we are merely a part of the present phase of change (whatever the impact we have on the Environment may be).
I have an issue with the concept of “natural”. Of course, we are part of nature, and it could be easily stated that therefore all of our influences are just part of nature, and we should therefore accept this. My issue is that if this is the case, then making guns and using them against one another is natural and should be accepted, driving cars and running people over is natural and should be accepted, getting a disease is natural and should be accepted – it’s just nature’s way. But I don’t think that there are too many sympathisers of this definition! I think that our own state of “naturalness “ has so far out-evolved everything else, that we should be clever enough to understand where to draw the line. We are natural for a given value of natural, but nothing else even comes close to this. The definition also implies therefore that because it is a natural process, we can just leave warming as it is, and not bother because life will rejuvenate after whatever the world will become in a few decades.
I think it unwise to remain inactive because we can’t decide on whether what we’re doing is natural or not. We know that the temperature is going to rise by at least a further 2°C because of emissions, wherever they came from, and that the consequences of this in many places will be dire, but we are in a position to do something about it! We should be able to take a moral stance, which is something that no other creature in the entire known suite of fauna is able to do, and react. It’s pressing enough, that the children of my children will suffer the penalties of our neglect. This is something that I for one, am not happy with!
You’re welcome to pick holes in the above [;)], but this does not remove the fact that it is going to happen, and whether it was us or not, we are the only species capable of ameliorating the situation.
George, I'd be very interested in your thoughts as to what should be done. You're very good at finding holes in my arguements (I have no problem with that!) but I haven't seen you put forward any of your own criteria and thoughts about how to achieve a suitable situation (maybe I missed them?). I'd like to read your "plan"......
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I have yet to come across a single scientific evaluation of the “anti” lobby that has withstood testing. Most seems to be based on very local effects and incorrect interpretation of peer reviewed evaluations. Certainly, there are few instances where the “pro” lobby can state beyond a “p” value of 1% on an given scenario, but I have not seen anything from the “anti’s” that can’t be swiftly shown to be incorrect. The latest is the effect of the solar cycle on climate change.
I suspect a lot of the probabilities depend on what assumption you make.
The 'debunking' of the solar cycle relates, if I read correctly, only to arguments about solar output, and over the last 20 years. Like the pro lobby, so the anti lobby, have been constantly refining their position, and the tendency now is to look for more subtle effect of the Sun that simply looking at crude solar output.
As I said, the other problem is that it only reflects figures for the last 20 years, and I suspect one of the greatest short term impacts over the last 20 years has been reduced global dimming due to reduced industrial pollution.
I have an issue with the concept of “natural”. Of course, we are part of nature, and it could be easily stated that therefore all of our influences are just part of nature, and we should therefore accept this. My issue is that if this is the case, then making guns and using them against one another is natural and should be accepted, driving cars and running people over is natural and should be accepted, getting a disease is natural and should be accepted – it’s just nature’s way. But I don’t think that there are too many sympathisers of this definition! I think that our own state of “naturalness “ has so far out-evolved everything else, that we should be clever enough to understand where to draw the line. We are natural for a given value of natural, but nothing else even comes close to this. The definition also implies therefore that because it is a natural process, we can just leave warming as it is, and not bother because life will rejuvenate after whatever the world will become in a few decades.
I think we humans can become extremely conceited at times. We have not out-evolved anything – we are, beneath a superficial veneer, just like every other animal (at least insofar as any two species of animal are alike); but ofcourse, we are more aware of our own capabilities and actions than we are aware of the capabilities and actions of animals that exist in a different social world to ourselves. The argument that humans are as a species more evolved than any other species is very reminiscent of the debates in the 19th and early 20th century that suggest than Europeans were more evolved than Africans.
Yes, making guns and using them against one another is natural, as it is natural for society to control the violence of one member of society against another (this is as true of ant societies as it is of human societies, even if the technological options may be different).
It is natural for society to try and control its local environment (so bees build hives, termites create mounds with very sophisticated temperature control within, but we are the first species to actually have the conceit to believe we can manage the Environment of the entire planet as if we were just building an air conditioning plant in our own homes. Yes, many species do have an influence on the global Environment, but none yet have control over it (lets just tweak the CO2 levels to reduce the temperature a bit), and I am highly doubtful that in any time in the near future, we shall achieve that control, and if we were to achieve that level of control, the outcome would be not only unprecedented, but I suspect unpredictable in its secondary effects.
I think it unwise to remain inactive because we can’t decide on whether what we’re doing is natural or not. We know that the temperature is going to rise by at least a further 2°C because of emissions, wherever they came from, and that the consequences of this in many places will be dire, but we are in a position to do something about it! We should be able to take a moral stance, which is something that no other creature in the entire known suite of fauna is able to do, and react. It’s pressing enough, that the children of my children will suffer the penalties of our neglect. This is something that I for one, am not happy with!
You’re welcome to pick holes in the above [;)], but this does not remove the fact that it is going to happen, and whether it was us or not, we are the only species capable of ameliorating the situation.
George, I'd be very interested in your thoughts as to what should be done. You're very good at finding holes in my arguements (I have no problem with that!) but I haven't seen you put forward any of your own criteria and thoughts about how to achieve a suitable situation (maybe I missed them?). I'd like to read your "plan"......
My plan would be to concentrate on doing what we know we can do, which is to mitigate against the inevitable, rather than trying to change the world, which I believe is still beyond our capabilities.
As you say, we know the temperature is continuing to rise, as it has since the 17th century, and we know that sea levels will probably rise (but even without that, there are constant geological changes that place areas of the world under increased threat of flooding).
We know how to build air conditioning plants, and how to build sea defences (even if they are imperfect, as they always have been, and would be even without any global warming). All of these things cost resources, but they are established technology with known outcomes. So we have a choice, we can conserve CO2 by not building air conditioning plants (despite the fact that we know temperatures will rise no matter what we do), or we can build those air conditioning plants, and be damned about the CO2 costs those might incur.
So do we take a massive gamble based upon unproven conjecture, supported by unproven technologies, and requiring major social upheaval; or do we do what we know how to do, based on known technologies with predictable outcomes. Maybe my answer to that is that I don't play the national lottery, nor gamble in casinos, so maybe I just am not that much of a gambler to be banking all my money on the untried and untested; and maybe I also lack the ambition to become God, and take control of the entire Earth's environment.
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tbc.....after hols!
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http://news.bbc.co.uk/1/hi/sci/tech/6916162.stm
Ozone could be a much more important driver of climate change than scientists had previously predicted, according to a study in Nature journal.
The authors say the effects of this greenhouse gas - known by the formula O3 - have been largely overlooked.
Ozone near the ground damages plants, reducing their ability to mop up carbon dioxide (CO2) from the atmosphere.
As a consequence, more CO2 will build up in the atmosphere instead of being taken up by plants.
This in turn will speed up climate change, say the Nature authors.
"Ozone could be twice as important as we previously thought as a driver of climate change," co-author Peter Cox, from the University of Exeter, UK, told the BBC News website.
Scientists already knew that ozone higher up in the atmosphere acted as a "direct" greenhouse gas, trapping infrared heat energy that would otherwise escape into space.
Ozone closer to the ground is formed in a reaction between sunlight and other greenhouse gases such as nitrogen oxides, methane and carbon monoxide.
Greenhouse emissions stemming from human activities have led to elevated ozone levels across large tracts of the Earth's surface.
Carbon take-up
This study is described as significant because it shows that O3 also has a large, indirect effect in the lower part of the atmosphere.
Research into ground-level ozone has tended to concentrate on its harmful effects on human lungs.
But the gas also damages plants, reducing their effectiveness as a "carbon sink" to soak up excess CO2 from the atmosphere.
Furthermore, Peter Cox said: "The indirect effect is of a similar magnitude, or even larger, than the direct effect."
There are uncertainties, Dr Cox admits; but he added: "Arguably, we have been looking in the wrong place for the key impacts of ozone."
A large amount of work has been carried out on the health effects of ozone.
Ozone enters plants through pores, called stomata, in the leaves. It then produces by-products that reduce the efficiency of photosynthesis, leaving the plants weakened and undersized.
Complex interactions
However, efforts to determine how rising levels of ozone will affect global plant growth are complicated by other factors.
High levels of both CO2 and O3 cause stomata to close. This means they take up less of the carbon dioxide they need for photosynthesis, but also absorb less of the harmful ozone.
The researchers built a computer model to estimate the impact of predicted changes in ozone levels on the land carbon sink over a period running from 1900 to 2100.
This model was designed to take into account the effect of ozone on plant photosynthesis and the interactions between O3 and CO2 through the closure of pores.
They used two scenarios, depending on whether plants were deemed to have high or low sensitivity to ozone.
Under the high scenario, ozone reduced plant productivity by 23%; under the low scenario, productivity was reduced by 14%.
"It's an interesting effect, and I don't think it has been introduced into a coupled [computer] model before so that the overall effect can be seen," said Dr Nathan Gillett, from the Climatic Research Unit at the University of East Anglia, UK, who was not involved in the study.
"Their finding that the effect on CO2 is larger than the radiative forcing from ozone itself makes it a significant contribution to climate change."
The above shows just how complex the issue of CO2 itself is (also see http://www.thenakedscientists.com/forum/index.php?topic=8681.msg107533#msg107533), let alone the complexities of other greenhouse gases (also see http://www.thenakedscientists.com/forum/index.php?topic=8981.msg108388#msg108388); and just how difficult it is to say how much of an effect reducing anthropogenic sources of CO2 will itself have. If we cannot say what effect it has, then how can we possibly use it as a means of control?
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Global warming is a major issue in the United States today, and lately, it seems it's been in the news more than ever. In 2008, a pivotal election year, every major or minor candidate running for office would be remiss not to address issues of fuel conservation, carbon emissions reduction, and alternative energy sources. New and used cars and trucks alike burn gasoline to enable motion, and gasoline burning is a major source of carbon dioxide emissions in the United States.
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I was convinced by this mans video/s that whether climate change is our fault or not, the most logical course of action is to reduce our carbon output. He claims he mounts an irrefutable case, and I am inclined to agree.