I wouldn't mind..

TIGERassault · Post by **TIGERassault** » Thu Oct 12, 2006 2:37 pm

ccb056 wrote:And im sure you have a bunch of sources to back you up. If you wouldn't mind, could you post some of those?

Sigh. Fine.
http://en.wikipedia.org/wiki/Greenhouse ... ater_vapor
That part continuously refers to water vapour as a feedback.

Duper · Post by **Duper** » Thu Oct 12, 2006 2:46 pm

ccb056 wrote:
yeah.. so um hurricanes are really no threat? How much vapor is thorwn into the atmosphere by hurricanes annually? There is more wholesale water vapor churned up by these storms on a global scale than any amount of moisture producing cars would.

get a grip.
after living on the guld coast for 8 years, and going through quite a few hurricanes, the majority of the water vapor the hurrricanes spew into the air is condesned rather rapidly

hurricanes, like any other natural phenomena, have very little effect on the long term climate changes, they are the result of climate changes, not the cause

That's really poor rational and unfounded. I've lived on the gulf coast too. Mind you that hurrcanes occur more frequently in other parts of the world.
Water vapor will not cause global warming. Water recyles quickly as you JUST pointed out. DUST and chemals that combine with elements in the air that destroy such things as the ozone in the upper atmosphere do not. Or rather very slowly. The earth is covered 2/3 woth water. I DARE you to find out how much water evaporates into the air in one day and stays there; also how much is recycled. Do some REAL science.

At least call or e-mail the National Weather Service on the matter. I'm sure thier facts are a will hold water Much better than Wikipedia. ...which btw, tried to tell me that B-25 bombers were launched off of Aircraft carriers at the battle of Midway.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 2:56 pm

according to tiger's wiki article, water vapor does contribute to global warming

The increased water vapor in turn leads to an increase in the greenhouse effect and thus a further increase in temperature; the increase in temperature leads to still further increase in atmospheric water vapor; and the feedback cycle continues until equilibrium is reached.

Kilarin · Post by **Kilarin** » Thu Oct 12, 2006 2:56 pm

ccb056 wrote:That all depends on what you consider polution. I assume you consider carbon dioxide polution. I'm also assuming you don't consider water vapor polution.

I was referring specifically to the stuff that makes the air brown, makes my eyes water, and makes me cough.

Water vapor and carbon dioxide are indeed important issues, perhaps even vital issues, but just reducing the smog levels would be very nice.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 3:00 pm

The earth is covered 2/3 woth water. I DARE you to find out how much water evaporates into the air in one day and stays there; also how much is recycled. Do some REAL science.

That 2/3 figure is liquid water, we are talking about water vapor. The reason water vapor from hurricanes condenses so quickly is because it never really had much energy to start with (compared to water vapor from hydrogen power exhaust). Second the earth is in equilibrium with the oceans, when you introduce a new variable, that equilibrium is shifted in one direction or another, the new variable is cars and factories producing high energy steam on a global scale all the time.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 3:02 pm

I was referring specifically to the stuff that makes the air brown, makes my eyes water, and makes me cough.

Water vapor and carbon dioxide are indeed important issues, perhaps even vital issues, but just reducing the smog levels would be very nice.

I agree, reducing smog levels is nice, but the consequences outweigh the benefits.

Lothar · Post by **Lothar** » Thu Oct 12, 2006 3:35 pm

ccb056 wrote:I don't really understand why you like hydrogen power so much

I never said I did. I'm not particularly a fan or an adversary of hydrogen power, I just want to look at the idea.

What I have said is that your arguments against it are sucky arguments.

You think "OMG GLOBAL WARMING!" is a great reason not to use hydrogen power. I think it's a crappy reason. You seem to think people using hydrogen cars will cause the earth to go into incredible environmental convulsions because of water vapor; I think your concerns are incredibly overblown. I have a good understanding of the way large-scale dynamical systems like the weather respond to parameter changes, and I simply don't see any good evidence that increased water vapor (in the amounts released by even millions of hydrogen-powered cars) is going to be a significant parameter we should spend a lot of time worrying about. In particular, I don't see evidence why it would be more significant than the current byproducts of fossil-fuel burning.

You also think "hydrogen is just like an alkaline battery" is a great reason not to use hydrogen power. I think it's a crappy reason. I think electric cars are just fine, and I have absolutely no problem with coming up with more efficient batteries for them -- and I'm pretty sure hydrogen is more efficient than your standard alkaline battery.

there are only 2 ways to get water vapor to condense

cool it
pressurize it

And you know this because of the ideal gas law, right? The ideal gas law is, by definition, only applicable to an ideal gas. Once you have a gas mixing with something else, the ideal gas law is no longer applicable. There are plenty of ways to encourage state changes in various chemicals just like there are plenty of ways to catalyze chemical reactions. Mixing with the right other chemical, or even just putting it on the right surface, can give you condensation.

Maybe you just need to put a filter in your exhaust pipe that has the right properties to grab water vapor but not oxygen or nitrogen gasses. Maybe you just need a really big heatsink :P

Testiculese · Post by **Testiculese** » Thu Oct 12, 2006 3:35 pm

Duper wrote:...will hold water...

Hahaha

Sorry, continue.

Even if ccb's wrong, you'se could be a little less confrontational. (Save it for religion

)

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 3:45 pm

Maybe you just need to put a filter in your exhaust pipe that has the right properties to grab water vapor but not oxygen or nitrogen gasses. Maybe you just need a really big heatsink

Neither one will work.

I am with you on the global warming issue surprising as it may seem. The reason I choose that as one of my arguments is that I assumed many of the proponents of hydrogen fuel are opposed to global warming. I honestly believe that carbon dioxide will not effect the atmosphere in such ways as melting ice caps or flooding costal areas. It is a fact that water vapor will contribute more to global warming than carbon dioxide.

If everyone agrees with the fact that water vapor contributes more to global warming than carbon dioxide I'll drop that issue.

If everyone agrees that water vapor, even though it contributes more to global warming than carbon dioxide, will not contribute to an extreme climate change, I'll drop the entire topic on global warming.

Keep in mind you just agreed that the current petrol driven economy we have now is not going to significantly contribute to global warming.

Now all that is left to argue is if there is a more optimized method for energy.

I however doubt we will get that far, you guys seem hung up on the global warming issue. But, I wouldn't mind being surprised.

Grendel · Post by **Grendel** » Thu Oct 12, 2006 4:02 pm

Keep in mind that increased temps will increase the airs capacity to carry water vapor regardless what causes the temp increase. Water vapor increase is already part of the climate system no matter what. Also keep in mind that the whole system is highly dynamic, ie. higher air temp --> more wv --> more cloudes --> more sun energy deflected into space --> air cooles off --> more clouds --> air cools more or more rain --> ?

I doubt anyone can predict the effect of increased release of wv at the cost of CO2 release so the whole discussion here drifts into a belief bashing.

I do belief a couple things tho:

- we are reintroducing locked away carbon into the biosphere vs. tapping the water circle as energy transport, ie.

- what cars currently exhaust will have a longer term effect on our climate & quallity of life than H2O exhaust

- creating H from rain will reduce the amount of extra H2O circulated

- H can be created w/ renewable energy sources, gasoline can't

Anyone wants to take a shot on the effects caused by the localized extra release of oxygen in the production of H ? ...

Lothar · Post by **Lothar** » Thu Oct 12, 2006 4:13 pm

you'se could be a little less confrontational.

Would being less confrontational make him less wrong?

ccb056 wrote:The reason I choose that as one of my arguments is that I assumed many of the proponents of hydrogen fuel are opposed to global warming.

Doesn't seem like many of us have made a big deal out of it. We only seem "stuck" on the issue because you've decided to focus on it.

If everyone agrees with the fact that water vapor contributes more to global warming than carbon dioxide I'll drop that issue.

You have to give a more precise measure before I can even answer that.

Do you mean the current amount of vapor causes more warming than the current amount of CO2? Do you mean that if you released equal volumes of water vapor and CO2 the water vapor would cause more warming? Do you mean the water vapor from one tank in this car would cause more warming than the pollutants from one tank of fossil fuel in a different car? Do you mean, if we switched all cars to hydrogen (via nuclear, solar, or wind) global warming would be worse than if we just kept fossil fuels? You have to explain more precisely what you mean by "contributes more".

Once you've decided what you mean by "contributes more" then we can decide whether (1) you're correct and (2) that particular measure is valid with respect to the topic at hand. If all you're arguing is that, right now, water vapor is the most significant greenhouse gas... I agree, but it's completely irrelevant. If you're arguing that changing to hydrogen cars (via a non-fossil-fuel route) would definitely shift the equilibrium temperature upward, I think you need to do the math before you can make that claim.

If everyone agrees that water vapor, even though it contributes more to global warming than carbon dioxide, will not contribute to an extreme climate change

I don't agree with that. Nor do I agree with the opposite.

All I'm saying is nobody has presented *good evidence* that it will / would if we all started driving these sorts of cars. There are several arguments and counterarguments -- water vapor traps heat, but water vapor condenses into clouds and then rain; water vapor traps heat, but if we reduced the amount of CO2 by the same amount as we increased water vapor, the net result is unknown. We need to have better models and better calculations before we should make our arguments with the level of confidence you seem to have.

Keep in mind you just agreed that the current petrol driven economy we have now is not going to significantly contribute to global warming.

I didn't. Nor did I agree that it is. I wanted to say "the jury is still out", but that sort of implies the evidence has all been presented and we're just evaluating it. I think a better way to state it is, the lawyers are still gathering evidence, and maybe one of these days we'll have a legit trial instead of both sides just biasing the jury pool through the media.

Now all that is left to argue is if there is a more optimized method for energy.

More optimized in what sense? In terms of the overall energy use of the entire system? In terms of the convenience of energy use?

Hydrogen shows promise because it could be incredibly convenient, provided it's combined with the appropriate technologies (like solar) to make it easy to charge up your car. It could also eliminate certain inefficiencies from the system, like the inefficiency of having to go out of your way to stop by the gas station, or the inefficiency of lugging around 100 pounds of fossil fuel when 10 pounds of hydrogen would give you similar power output. But, of course, that doesn't mean it's a perfect technology -- just that it has some things going for it.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 4:17 pm

what cars currently exhaust will have a longer term effect on our climate & quallity of life than H2O exhaust

longer, yes, but of less magnitude

creating H from rain will reduce the amount of extra H2O circulated

it doesnt rain enough to take rainwater and convert it into hydrogen, you would need huge costly infastructure and that money is better spent in other areas of energy

H can be created w/ renewable energy sources, gasoline can't

no energy source is \"renewable\"

Anyone wants to take a shot on the effects caused by the localized extra release of oxygen in the production of H ?

the first thing that comes to mind is oxygen is naturally an oxidizer

, which means that it will probably react with alot of stuff it comes in contact with; there is alot of carbon and nitrogen out there, so the ogygen will probably react with them, forming NO and CO2, which are both greenhouse gasses

Grendel · Post by **Grendel** » Thu Oct 12, 2006 4:23 pm

ccb056 wrote:
H can be created w/ renewable energy sources, gasoline can't
no energy source is "renewable"

http://en.wikipedia.org/wiki/Renewable_energy wrote:Renewable energy sources, or RES, are those energy sources which are not destroyed when their energy is harnessed. Renewable energy sources are distinct from fossil fuels, which must be consumed to release energy. Human use of renewable energy requires technologies that harness natural phenomena, such as sunlight, wind, waves, water flow, biological processes such as anaerobic digestion, biological hydrogen production and geothermal heat.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 4:28 pm

Lothar, I'm not going to argue with someone who doesn't have an opinion, sorry.

Grendel

First law of thermodynamics- The increase in the energy of a closed system is equal to the amount of energy added to the system by heating, minus the amount lost in the form of work done by the system on its surroundings.

Second law of thermodynamics- The total entropy of any isolated thermodynamic system tends to increase over time, approaching a maximum value.

I think it's safe to assume that the universe is a closed system, according to laws 1 and 2, we will eventually run out of useable energy. Now, I may be wrong if you can disprove those 2 laws, but good luck with that.

Grendel · Post by **Grendel** » Thu Oct 12, 2006 4:39 pm

Glad to see you paid attention in your physics class -- why don't you go ahead and change that wiki article mentioned above ?

http://www.etymonline.com/index.php?term=renew wrote:renew
1382, from re- "again" + M.E. newen "resume, revive, renew;" on analogy of L. renovare. Renewable is recorded from 1727; in ref. to energy sources, it is attested from 1971.

TIGERassault · Post by **TIGERassault** » Thu Oct 12, 2006 4:46 pm

Hmm...

ccb056 wrote:I am with you on the global warming issue surprising as it may seem.

WE KNOW! It's friggin obvious from the amount of times you posted about how water vapour is increasing the heat. (and can you please stop telling us that water vapour does increase the heat? We already knew a number of posts before, and it's just getting annoying at this stage)

ccb056 wrote:It is a fact that water vapor will contribute more to global warming than carbon dioxide.

FALSE!
You can't make an estimate of the future and then consider it fact.

ccb056 wrote:If everyone agrees with the fact that water vapor contributes more to global warming than carbon dioxide I'll drop that issue.

I can't; it's fairly unmeasurable. Water vapour isn't a greenhouse gas itself, it only traps other greenhouse gases.

ccb056 wrote:If everyone agrees that water vapor, even though it contributes more to global warming than carbon dioxide, will not contribute to an extreme climate change, I'll drop the entire topic on global warming.

I disagree. But...

ccb056 wrote:Keep in mind you just agreed that the current petrol driven economy we have now is not going to significantly contribute to global warming.

Not me, and I disagree on this too.

ccb056 wrote:Now all that is left to argue is if there is a more optimized method for energy.

I however doubt we will get that far, you guys seem hung up on the global warming issue. But, I wouldn't mind being surprised.

It is very, very unlikely that we'd be able to think up of a completely new idea for transport that even the top scientists didn't think of.

ccb056 wrote:according to tiger's wiki article, water vapor does contribute to global warming

Ok, ok, you're not going to comment on my point...

Lothar · Post by **Lothar** » Thu Oct 12, 2006 4:47 pm

ccb056 wrote:Lothar, I'm not going to argue with someone who doesn't have an opinion, sorry.

If your argument can't stand up to outside criticism, you shouldn't stand by it so much. In this sense, it shouldn't matter one bit whether I'm arguing against you because I'm a hydrogen evangelist with a firm position, or whether I'm arguing because your argument has some holes and I just want to see what happens if you patch them up because I haven't made up my mind at all. Either way, you should be able to support your position.

The only way in which it should matter is this: I'm not hostile, so at least you have a chance of convincing me. I'm arguing because your argument has holes, not because I'm an evangelist for some other position.

By dodging my questions, you put yourself in a much worse place when it comes to being convincing. My questions are now out there in everyone's minds, and if you can't address them, your argument is weaker.

the universe is a closed system, according to laws 1 and 2, we will eventually run out of useable energy.

True, but irrelevant. "Renewable energy" is not meant to be a universal absolute; it's just a convenient way to refer to sources of energy that aren't going to be "used up" in the near future because they're continually renewed by the sun. Yes, billions of years down the road, the sun will burn out and those resources will no longer be renewed, but that really doesn't matter within the timescales being referred to in this thread. (Similarly, it doesn't matter that, after the sun burns out, the earth will be an incredibly cold mass of rock, or possibly an incredibly cold scattered cloud of gas; global warming is an issue on a much shorter timescale.)

TIGERassault · Post by **TIGERassault** » Thu Oct 12, 2006 4:52 pm

ccb056 wrote:Lothar, I'm not going to argue with someone who doesn't have an opinion, sorry.

Grendel

First law of thermodynamics- The increase in the energy of a closed system is equal to the amount of energy added to the system by heating, minus the amount lost in the form of work done by the system on its surroundings.

Second law of thermodynamics- The total entropy of any isolated thermodynamic system tends to increase over time, approaching a maximum value.

I think it's safe to assume that the universe is a closed system, according to laws 1 and 2, we will eventually run out of useable energy. Now, I may be wrong if you can disprove those 2 laws, but good luck with that.

The universe has no surroundings and cannot be heated by external forces. Therefore, the universe will never gain or lose energy. Hence the law 'energy cannot be created or destroyed. It can only be changed from one form to another.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 4:59 pm

Second law of thermodynamics- The total entropy of any isolated thermodynamic system tends to increase over time, approaching a maximum value.

If you don't know what entropy is and how it relates to energy, look it up.

TIGERassault · Post by **TIGERassault** » Thu Oct 12, 2006 5:05 pm

ccb056 wrote:Second law of thermodynamics- The total entropy of any isolated thermodynamic system tends to increase over time, approaching a maximum value.

If you don't know what entropy is and how it relates to energy, look it up.

"...approaching a maximum value."
Thus meaning that non-entropical energy will never run out.

Jeff250 · Post by **Jeff250** » Thu Oct 12, 2006 5:23 pm

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 5:23 pm

LOL

You can't be serious, the only way to capture energy is on its transition from low entropy to high entropy.

Tiger, idk what your background is, but I'm hoping it is not science nor enginering.

TIGERassault · Post by **TIGERassault** » Thu Oct 12, 2006 5:54 pm

Oh right, yes. I didn't understand that the maximum value was referring to the point where all energy becomes entropical.

...it's also too-offtopic at this point. Whether or not something can be truly renewable is not related to which is the better fuel scource.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 6:00 pm

not true, entropy, and more specifically, thermodynamics are the keys to understanding energy.

the fact that I have to even explain how these things work to people arguing against me shows that they have almost no knowldge of energy

Lothar · Post by **Lothar** » Thu Oct 12, 2006 6:28 pm

ccb056 wrote:the fact that I have to even explain how these things work to people arguing against me shows that they have almost no knowldge of energy

You've got quite the game going on here.

I clearly know what I'm talking about and poke holes in your ideas left, right, and sideways. So you won't talk to me because I don't have an opinion.

TIGERassault sees some things wrong with your argument, so you change the subject to entropy and use his lack of knowledge on that point to dismiss the rest of his arguments.

Grendel pwnz you on a couple of points, and you retreat into talking about the heat death of the universe -- something happening on a timescale far different from the rest of the issues in this thread.

And you wonder why you're not convincing anybody...

TechPro · Post by **TechPro** » Thu Oct 12, 2006 6:34 pm

Well...

Obviously, the only way to *satisfy* both sides of this \"discussion\" is for us to all just levitate ourselves around... and to stop breathing (since that is 'pollution' as defined by this \"discussion\"...).

Wouldn't that be a smart thing to do.

Come on, guys! You're all smarter than that! Let's just work on making things better by gaining better methods. As we get better about the critical things... we can then start working on the not as critical.

TIGERassault · Post by **TIGERassault** » Thu Oct 12, 2006 6:44 pm

TechPro wrote:Come on, guys! You're all smarter than that! Let's just work on making things better by gaining better methods. As we get better about the critical things... we can then start working on the not as critical.

Come to think of it, I can't really think of anything more crucial...

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 6:55 pm

TechPro wrote: Obviously, the only way to *satisfy* both sides of this "discussion" is for us to all just levitate ourselves around... and to stop breathing (since that is 'pollution' as defined by this "discussion"...).

I never said I wanted to eliminate all chemical emissions, I'm simply saying that using hydrogen power only increases the emissions.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 7:03 pm

Lothar, I find it highly unlikely that you know so much about thermodynamics and do not have an opinion on hydrogen power, I'm calling BS.

Thing is, I can't tell which is BS, the notion that you know so much about thermodynamics, or the notion that you don't have an opinion.

Krom · Post by **Krom** » Thu Oct 12, 2006 7:37 pm

Lothar is not the type to claim extensive knowledge in something if he didn't actually have that knowledge. Is it a requirement of knowing the laws of thermodynamics to have an opinion on hydrogen fuel cells? I think not.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 7:40 pm

to have a valid opinion on hydrogen power you better have knowledge of thermodynamics

if lothar has the knowldge he claims he does about thermodynamics, I doubt he doesn't have an opinion on it

Lothar · Post by **Lothar** » Thu Oct 12, 2006 7:43 pm

ccb056 wrote:I find it highly unlikely that you know so much about thermodynamics and do not have an opinion on hydrogen power

Why is that so hard to believe? I really DO know an awful lot about thermo, among other things, and I really DON'T have an opinion on hydrogen power overall.

(Believe it or not, I was thinking about this very subject earlier -- wondering if someone would say I *must* have an opinion on hydrogen power.)

People seem to have this idea that everyone has to have strong opinions on various subjects, especially smart people and especially on subjects they know a lot about. Uncertainty is viewed as weakness or ignorance -- "I don't know" is considered the worst answer possible, while "I'm certain of X" is considered admirable and intelligent, even if X turns out to be utterly false. People think it's better to say "2+2=5" than "I don't know what 2+2 is"! That's retarded, but that's the perception people have.

People, therefore, make a habit out of having answers -- not nessarily GOOD answers or answers that take account of all the evidence, just answers. They make a habit of taking sides immediately, in any debate, regardless of whether or not they actually have the knowledge necessary.

I think that's a crappy way to live your intellectual life. As the saying goes, "it's not what we don't know that gets us in trouble, it's what we know that just ain't so." The right and sensible way to approach issues is to form your opinion as the evidence leads, and to hold your opinion only as strongly as the evidence is. Don't "know" anything you don't have good reason to know; be willing to say "I have to gather more evidence." Of course, this means you have to have good methods for gathering evidence -- and one of those is to question relentlessly when people present ideas they believe to be relevant.

I don't know whether hydrogen power is a good idea or not. I can see some pros to it, and I can see some cons to it, and I can see a lot of questions that need to be asked. So I seek evidence. Both sides have tried to provide it, though you've been much more insistant that yours PROVES you correct, and your arguments have had more consistantly obvious holes. If you have any worthwhile evidence, I want it -- but I don't want to buy into bogus evidence because I failed to ask enough questions. That means, when you say "Hydrogen power is [good / bad] for reason X" I'm going to question you about reason X until I'm either satisfied that it's a good reason, convinced it's a bad reason, or know what research I have to do in order to find out. And that means, when you respond by saying "I won't answer", by dodging the question, by retreating into arguments about the heat death of the universe, etc. you're not helping.

If you want to call BS on something... call BS on the stupid philosophy that says it's better to "know" something wrong than to admit you don't actually know.

Krom · Post by **Krom** » Thu Oct 12, 2006 7:45 pm

I also doubt he doesn't have an opinion, but I assume he does not see a reason to express his opinion, or he feels there is not sufficient evidence to form a valid or strong opinion at all and that is why he is debating with you in the first place.

Duper · Post by **Duper** » Thu Oct 12, 2006 8:29 pm

Lothar wrote: People seem to have this idea that everyone has to have strong opinions on various subjects, especially smart people and especially on subjects they know a lot about. Uncertainty is viewed as weakness or ignorance -- "I don't know" is considered the worst answer possible, while "I'm certain of X" is considered admirable and intelligent, even if X turns out to be utterly false. People think it's better to say "2+2=5" than "I don't know what 2+2 is"! That's retarded, but that's the perception people have.

Interesting you should post that Lothar. I have a habit(pointedly) of when someone tells me: "I don't know" to tell them "Good answer". they always look at me funny and then I tell them that it's better than making something up. I grew up with a younger brother that habitually lied. I got VERY tired of it. .. he's not as bad now, but he does stretch the truth where he thinks he can get away with it.

Over all, this is pretty cool car. The tech they developing is still very new and has promise. Personally, I'd like to see the price some down a bit.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 9:28 pm

Believe it or not, I'm not going to be able to post as often because the 120GB WD drive in my workstation just started giving SMART errors and I can no longer boot into XP. I'll do what I can from my quad xeon server, but don't expect much.

ccb056 · Post by **ccb056** » Thu Oct 12, 2006 9:36 pm

Do you mean the current amount of vapor causes more warming than the current amount of CO2?

Yes

Do you mean that if you released equal volumes of water vapor and CO2 the water vapor would cause more warming?

yes

Do you mean the water vapor from one tank in this car would cause more warming than the pollutants from one tank of fossil fuel in a different car?

yes

Do you mean, if we switched all cars to hydrogen (via nuclear, solar, or wind) global warming would be worse than if we just kept f6ossil fuels?

yes

More optimized in what sense? In terms of the overall energy use of the entire system? In terms of the convenience of energy use?

I am using optimized to refer to the energy lost in the process of taking energy from a source and using it to produce work, the less energy lost the more optimized a system is.

Hydrogen shows promise because it could be incredibly convenient, provided it's combined with the appropriate technologies (like solar) to make it easy to charge up your car.

Hardly, hydrogen will either have to be supercooled or pressurized, the process of transporting hydrogen to a tank will be much more complicated than driving up to a gas station and pumping fuel into a car.

Grendel · Post by **Grendel** » Thu Oct 12, 2006 10:39 pm

Let me quote you back:

ccb056 wrote:http://www.space.com/scienceastronomy/p ... 00128.html
"Water vapor is really the primary greenhouse gas in the atmosphere and has a greater influence on global warming than carbon dioxide, but we're not sure whether this increase of water in the atmosphere will lead to an increase in global warming."
http://physicsweb.org/articles/world/16/5/7
Water vapour is responsible for 70% of the known absorption of incoming sunlight, particularly in the infrared region.

The 2nd quote is grossly out of context -- here's some more from the same article w/ some higlights:

For example, it is now well established that the top of the Earth's atmosphere receives a surface-averaged energy input from the Sun of 342 W m-2. This is calculated by knowing the amount of energy that is radiated by the Sun and the angle that the Earth subtends. If the incoming and outgoing radiation is not equal then the global energy budget does not balance and the temperature of the planet will change until a new balance is established. What is feared is that a build-up of greenhouse gases is causing an increase in the absorption of the outgoing, infrared radiation.

Satellite measurements show that 235 W m-2 of incoming solar radiation is absorbed by the Earth, but the latest models and measurements suggest that the atmosphere is responsible for just 67 W m-2 of this amount. The rest is absorbed by the ground and by the oceans, which play a key role in the energy budget due to their large heat capacity and their ability to store carbon dioxide, and, of course, water vapour.

[..]

Not all models underestimate the amount of atmospheric absorption because some physicists choose to add extra absorption to their models to mop up the surplus radiation. However, the physical cause of the missing clear-sky absorption and its exact wavelength distribution remain unresolved, and a source of fertile speculation. Everyone's favourite molecule is always a candidate.

Our favourite molecule is water. Water vapour is responsible for 70% of the known absorption of incoming sunlight, particularly in the infrared region.

[..]

We should not pretend that the effects of carbon dioxide are unimportant in the greenhouse effect. While the atmosphere has always contained a significant amount of water vapour, it is the apparent increase in atmospheric carbon dioxide since the period of industrialization that is causing so much concern. It turns out that typical abundances of carbon dioxide are sufficient to make most of its absorption bands relatively opaque (see figure 3). Because the strong absorption bands are saturated, adding more carbon dioxide to the atmosphere increases its absorptions logarithmically rather than linearly - a fact that is recognized by the Intergovernmental Panel on Climate Change.

The concentration of water vapour in the atmosphere is strongly related to temperature, as can be seen in figure 1. It might therefore appear that an increased greenhouse effect, which causes the atmosphere to get warmer, would also lead to more water vapour in the atmosphere. This would result in a positive-feedback system that causes the Earth to become increasingly warmer. However, as is often the case with atmospheric processes, the situation is not quite this simple. Water vapour in the atmosphere can change phase, which leads to more clouds, and greater cloud cover means that more sunlight is reflected straight out of the atmosphere. Crude calculations suggest that the two effects approximately balance each other, and that water vapour does not have a strong feedback mechanism in the Earth's climate.

[..]

It is clear that the absorption of radiation by water vapour determines many characteristics of our atmosphere. While we would not try to provoke any worldwide movement that was aimed at suppressing water emissions, it would seem that the climatic role of water does not receive the general attention it deserves.

What does that tells us ? Mainly two things: 1. CO2 is bad and its badness increases logarithmically. 2. It's not an established fact that more WV will increase temperatures on this planet, actually very little is known about the effects of increased WV in the air. I think you have a very weak stand w/ your opinions. Actually the arcticle above strenghtens my believe that we are better of w/ H emissions at the cost of CO2 emissions.

Kilarin · Post by **Kilarin** » Thu Oct 12, 2006 11:57 pm

Boiling water to create energy has simply GOT to create more water vapor than a fuel cell does. The relative effeciencies are worlds apart.

So, I'm wondering, obviously we have a larger industrial base currently, but are there any numbers or guesses as to what affects all of the extra water vapor being dumped into the atmosphere during the steam age had? I've read lots of reports of problems with the soot and ash from the wood/coal fires, but I don't remember any reports of increased humidity or noticable changes due to the water vapor.

Again, yes, I REALIZE that we have LOTS more cars now than they had steam engines then, but each steam engine should have produced a LOT more steam than any fuel cell, so I don't think the comparison is completely out of line. Of course, environmental reporting was kinda scanty back then...

Top Gun · Post by **Top Gun** » Fri Oct 13, 2006 12:17 am

Very nice quotes there, Grendel. I'm inclined to agree with your belief. Seeing as how the amount of water vapor in the air is a self-regulating system (which, considering the fact that the water cycle has been going on for millions of years of this planet, makes perfect sense), I fail to see how pumping more vapor into the atmosphere will create any sort of \"runaway effect.\"

There's also the question of \"equal emissions\" that seems to have been just about completely ignored up until this point. Remember, combustion of any sort produces carbon dioxide and water vapor as its main products (along with small amounts of substances like soot and carbon monoxide). We're already throwing plenty of water vapor into the atmosphere every time we turn on our cars; it's not like we're switching directly from carbon dioxide to water vapor. Even ignoring that point, who says that a hydrogen-powered car will produce an equal amount of gaseous emissions as your standard internal-combustion engine of today? Does anyone have actual chemistry to back this up? For all I know off the top of my head, the water vapor output of a fuel cell would be substantially less than the water vapor/carbon dioxide/whatever output of my car. If that's the case, then not only would we be ditching the carbon dioxide output entirely, but we'd also be cutting down on the amount of water vapor that our cars already produce, which is pretty much a win-win-win situation.

And ccb, I think you're kind of completely missing the point when you refer to water vapor as a \"greater contributor to global warming\" than carbon dioxide. The only thing that the data that you and others have posted states is that, mole-for-mole, water vapor holds heat in somewhat better than carbon dioxide. That's it. You're completely brushing over the fact that water vapor has a much shorter lifespan in the atmosphere than carbon dioxide; based on the data I've seen, it would seem like the much-longer-lasting CO2 would manage to create much more of a warming effect over the long-term than the same amount of H20, which is only in the atmosphere for a short time, would. But again, since no one's really done any long-term studies about this, there's absolutely no room to state anything as a definite fact.

You also seem to be completely glossing over the possibility that the increased levels of water vapor are simply a cause of more CO2, a correlation which a least one of those studies pointed out. More CO2 leads to warmer temperatures, which leads to more evaporation and an increased atmospheric capacity for water vapor. Even with that, like we said, the water cycle is self-regulating, so things would seem to be able to find a happy medium. The bottom line is, if humans were to drastically decrease their CO2 output, why wouldn't it be reasonable to expect temperatures to decrease; if the extra water vapor created as a result of CO2 is removed, then temperatures will fall, even if we pump a certain (and potentially far less) amount of water vapor back into the atmosphere.

The bottom line, ccb, is that you seem to be flinging about a whole lot of \"facts\" that don't seem much more than your personal opinions. If no one's ever fully modeled the long-term effects of increased water vapor levels on Earth's temperature before, how can you be so certain that your claims are true?

P.S. And don't bother flinging the laws of thermodynamics at me; if I felt arsed to consult my thermo text from last semester, then I could fling them right back at you in context.

roid · Post by **roid** » Fri Oct 13, 2006 2:38 am

When ccb first suggested the whole water vapour global warming thing i was unfamilure with the theory so i tried to look it up. I read about water vapour's influence as a greenhouse gas and it was quite interesting. HOWEVER, i was very soon taught why it wasn't worth worrying about: every website i read included disclaimers explaining how humans generally don't effect levels of water vapour much, and when we do it's very local and then quickly precipitates out.

So, it's a facinating theory CBB, but even the websites you linked to have the disclaimers - indicating that you are purposefully taking things outof context with no respect for accuracy. This, and a lot of other things, are suggesting to me that you are just trolling.

But as i said, your ideas are interesting. It's just the arrogent trolling style that's grating.

Lothar and TopGun sum up what i think pretty well:

lothar wrote:If you're arguing that changing to hydrogen cars (via a non-fossil-fuel route) would definitely shift the equilibrium temperature upward, I think you need to do the math before you can make that claim.