TerraPass blog

How to turn 6 pounds of gasoline into 20 pounds of carbon dioxide

Adam Stein

by Adam Stein – March 21, 2006
 

Chemistry is coolThe curious (or suspicious-minded) among you have occasionally wondered about our claim that one gallon of gas turns into about twenty pounds of carbon dioxide exhaust. Your high school chemistry teacher would be very disappointed with you for even thinking the question, but there’s no judging here at TerraBlog. Let’s walk through the math.

Short answer:

When you burn something, it might feel like you’re turning it into lightness, air, nothingness. But what you’re really doing is simultaneously vaporizing it and chemically bonding it with oxygen in the air to make it much heavier than it was in solid form.

Carbon dioxide — or CO2 — is one carbon atom joined to two oxygen atoms. Carbon dioxide. CO2. Oxygen is a little bit heavier than carbon, so when you stick two oxygen atoms onto every available carbon atom, you roughly triple the weight of the gasoline.

Long answer:

One gallon of gas weighs about 6.25 pounds. The weight fluctuates with temperature and octane, but this figure is good enough for government work.

Let’s pretend that gas is entirely made up of octane (more properly referred to as 2,2,4-trimethylpentane). It’s not, but that also doesn’t really matter for our purposes. Octane contains 8 carbon atoms (hence the oct- prefix, like Dr. Octopus) and 18 hydrogen atoms. Carbon has a molecular weight of 12 and hydrogen has a molecular weight of 1, so octane has a total molecular weight of 114 (8 x 12 + 18 x 1).

Oxygen has a molecular weight of 16, so CO2 has a total molecular weight of 44 (12 + 16 + 16). Every molecule of octane makes eight molecules of CO2, with a total molecular weight of 352 (44 x 8).

6.25 pounds x (352 / 114) = 19.3 pounds

Et voila! All it takes to convert 6 pounds of gas into 20 pounds of carbon dioxide is some highly confusing algebra!

Bonus material:

Gas doesn’t burn 100% cleanly. You also get some carbon monoxide and other nasty stuff coming out of your tailpipe. But that doesn’t really affect our math very much. The official World Resources Institute conversion rate that we use in our carbon calculator is 19.564 pounds of CO2 per gallon of gas.

Also, your exhaust is quite a bit heavier if you count the steam that is generated. Those 16 hydrogen atoms attached to every octane molecule have to go somewhere. They combine with oxygen to create water (H20). Every gallon of gas creates roughly 8 pounds of water vapor. And water vapor does, believe it or not, contribute to global warming.

Aren’t you sorry you asked?

Update: A small point of clarification — even though water vapor is a significant contributor to global warming, you don’t have to feel guilty about taking hot showers. Direct human contributions to atmospheric water vapor are small. Rather, humans have a large indirect impact on atmospheric water vapor when we create carbon dioxide, which warms the atmosphere, which warms the oceans, which creates more water vapor, which warms the atmosphere…

Update 2:Fixed a math typo, corrected the number of hydrogen atoms in octane, and changed the headline to reflect more clearly that the gasoline is turned into carbon dioxide, not carbon. We’re drivers, not alchemists.

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Further reading

Comments

1. Comment by John @ Mar 22, 2006 7 AM Comment permalink

Facinating high school chemistry - it’s funny people still think solids as more sgnificant even if in weight, volume and effect as a pollutant are greater in the form of a “harmless”, colourless, odourless gas. Just one point though the header talks about Carbon - the calc is for Carbon Dioxide (a much weighter product).

2. Comment by JasonPStewart @ Mar 22, 2006 8 AM Comment permalink

Interesting. You may want to change your literature to talk about creating 20 lbs of “Carbon Monoxide” not “Carbon”. I figured the extra 14 lbs of “Carbon” came from the energy used to pump, transport and refine the stuff before it got to my gas tank (I’m still curious how much that is).

3. Comment by Anonymous @ Mar 22, 2006 9 AM Comment permalink

Not to be one of those people, but you’ve got a dyslexic typo in your calculations. The line:
6.25 pounds x (325 / 112) = 19.64 pounds
should read:
6.25 pounds x (352 / 112) = 19.64 pounds

4. Comment by Adam @ Mar 22, 2006 10 AM Comment permalink

Thanks. Typo fixed and headline updated.

5. Comment by Anonymous @ Mar 22, 2006 11 AM Comment permalink

I believe that the chemical formula for 2,2,4 Trimetylpentane (Isooctane) is (CH3)3CCH2CH(CH3)2 and think that this molecule has 18 hydrogens rather than 16. Doesn’t it have a weight is 114.2285 g/mol rather than 112? If I then use your formula with this revised weight but retain your estimate for the weight of 1 gallon of gasoline (6.25 lb. per gallon), I get 19.3628 lbs of CO2 per gallon. Am I doing this right?

6. Comment by Adam @ Mar 22, 2006 11 AM Comment permalink

Argh. Yes, you’re right. This should have been obvious to me — regardless of the exact configuration of the octane, it’s always going to have eight carbon atoms, which means 32 free electrons. 14 of those electrons will be paired up in carbon-carbon single bonds, leaving 18 free electrons for the hydrogen to bond to. My high school chemistry teacher is very unhappy right now.

I’ve updated the math.

P.S. You’re using a far more precise atomic mass than me. I’m sticking with the round numbers.

7. Comment by Anonymous @ Mar 22, 2006 1 PM Comment permalink

Regarding your update on water, the important difference between water and carbon dioxide is that the carbon dioxide we add to the atmosphere sticks around for about 100 years…

The scientific term is “residence time.” Water vapor, by contrast, has a residence time on the order of days. (This is not to mention that the amount of water vapor the atmosphere can hold is also a function of temperature.) In any event, it’s true that our contribution to water vapor is insignificant. Pointing this out is a good opportunity to highlight an important part of emmissions problem… it’s at least 100 year commitment.

8. Comment by reliapundit @ Mar 24, 2006 10 AM Comment permalink

If the increase in atmospheric CO2 is causing global warming, then what is the most effective and least painful (economically) thing to do about it?

The answer is NOT KYOTO - which the signatories have either abandoned or violated, and which doesn’t include India, China or the USA - the largest emitters of man-made CO2.

The answer is clear-cutting (and then replanting) the Amazon Rainforest.

Old tress do not sequester as muich CO2 as young, growing/fast-growing trees.

UC-Irvine has recently proven that the Amazon - which sequesters abiout 1/3 of all the CO2 ion the world - is now mostly comprised of very VERY old trees; therefore, the Amazon Rainforest is no longer absorbing/sequestering as much CO2 as it used to - - as when the most of the Amazon’s trees (and therefore the Amazon Rainforest as a whole) were younger.

THIS MIGHT BE THE CHEIF REASON GLOBAL ATMOSPHERIC CO2 HAS INCREASED.

THEREFORE, if we REALLY want to reduce the amount of CO2 in the atmosphere we should clear-cut huge swathes of the Amazon and replant with young trees.

In order to prevent the cut trees from decaying - and thereby putting their sequestered CO2 back into the atmosphere - we would need to use the trees for their lumber - either for furniture or for housing. (The world’s poor - in India, Chuina and Africa, and South Amerioca - could use BOTH!)

So it’s a win-win: the CO2 in the atmosphere gets reduced, and poor people get housing and furniture.

HOW COULD ANYONE OPPOSE THIS POLICY?!

I have posted on this three or four times at my blog - each post is linked to a few SCIENTIFIC STUDIES.

9. Comment by Rqball John @ Mar 24, 2006 6 PM Comment permalink

Just curious, doesn,t any of that carbon in a gallon of gas get used in the explosion, or is all of it expelled out the tail pipe?

10. Comment by Adam @ Mar 24, 2006 10 PM Comment permalink

All out the tailpipe. An explosion doesn’t have much meaning at an atomic level. Although an explosion looks dramatic from where we’re sitting — with the bang and the pretty fireball and the bits flying everywhere — at the level of a carbon atom it doesn’t look like anything at all. It’d be kind of like you concentrating real hard to try to feel the earth spinning around the sun.

Carbon atoms don’t get “used” when gas is burned. They just move around really fast and bond to other atoms. What does get used is the energy contained in the bonds that join the carbon molecules together. This is kind of an abstract concept to get your head around, but imagine it like the old snakes-in-a-can trick. The coiled springs are the bonds joining the carbon atoms together. When the can is opened, the springs are released, and the snakes jump out. Ditto for the carbon atoms.

11. Comment by Dan @ Mar 25, 2006 7 AM Comment permalink

How much C02 does a volcano produce?

12. Comment by Adam @ Mar 25, 2006 9 AM Comment permalink

What am I, Mr. Wizard?

The answer is a little surprising. While volcanoes don’t release a significant amount of CO2 compared to humans, they still release quite a bit more than I thought.

One conservative estimate puts the amount of CO2 released every year by volcanoes at about 150-200 million tons (which you could offset with about 10 million Utility TerraPasses). This is a big number, but the amount created by humans every year is about 150 times bigger.

Another online source says that volcanoes produce about 3% of annual CO2 emissions. I have no expertise that allows me to evaluate these separate claims.

Incidentally, the way vulcanologists go about figuring this sort of thing out is to tape sensors to the front of a helicopter and fly them into active volcanoes. That is so freaking cool.

Update: This comment has been promoted to a full post, with a few extra tidbits included: http://www.terrapass.com/terrablog/posts/000192.html


13. Comment by David Biddle @ Mar 27, 2006 8 AM Comment permalink

Seeing this entire page unfold from the explanation through the comments and corrections should give us hope for what we’re all trying to get at. I am so impressed with the collaborative process in approaching global warming and climate change. Sometimes it seems like the process of thinking through these issues may well end up being the real story (once we get things in working order that is…)

14. Comment by Ron @ Apr 5, 2006 3 PM Comment permalink

First, how ‘bout not calling gasoline “gas,” since it is a liquid and may be confusing to some.

More importantly, would you please give us the volume that 20 pounds of CO2 occupies at atmospheric pressure and, say, 70 degrees F?

Keep up the good work.

15. Comment by Adam @ Apr 6, 2006 10 AM Comment permalink

Your wish is my command. Headline updated. Volume calculation here.

16. Comment by Anonymous @ Apr 22, 2006 4 PM Comment permalink

Wow, that’s really helpful! I’m doing a paper that deals with emissions, so it’s important to have the numbers right. I just have one question:

How can 6 pounds of gasoline = 20 pounds of CO2? You can’t create or destroy matter.

My guess is that the process pulls oxygen from the air in the process of bonding, and then when it is all said and done, you have 20lbs of CO2. Correct?

17. Comment by Adam @ Apr 22, 2006 4 PM Comment permalink

Correct. Normally I’d link to the post that explains all this in detail, but…this is the post that explains all this in detail.

18. Comment by Anonymous @ Apr 22, 2006 4 PM Comment permalink

I guess that was my problem-the details. That’s some pretty complex algebra!

So also, I see a potential problem with the replanting the African rainforests theory. It seems that all of those tree are “holding” if you will the CO2. So when you create furniture, or burn the wood for fires or make paper, you would be releasing that CO2 back into the atmosphere. At least then you would have the wood, as the new trees would start to absorb that old CO2 as well as the new stuff. But there has to be a limit to that too.

Also, in the process of replanting, you’d probably take out all sorts of creatures who have made their home in the old trees.

Agree?

19. Comment by Adam @ Apr 22, 2006 5 PM Comment permalink

Replanting forests is a good thing, and there are some organizations that create carbon offsets by planting trees. There are also some issues with this mode of carbon sequestration, which I won’t go into, because I’m not enough of an expert.

In general, yes, organic matter is part of the natural carbon cycle, which is why we consider biofuels to be better than fossil fuels. We create carbon dioxide when we burn the biofuels, but the carbon dioxide then gets recycled back into plant matter. This is very different than pumping the carbon out of the ground.

I know some people are proponents of the “mow down all the forests and let them regrow” theory of carbon sequestration. Can’t say that I’m a fan.

20. Comment by Marc Berner @ Jun 10, 2006 2 AM Comment permalink

Many thanks. Saw “An Inconvenient Truth” last night and just enrolled in Terra Pass. May this grassroots campaign spread like a wildfire to heal the earth.

21. Comment by Wayne @ Aug 1, 2006 6 PM Comment permalink

Say, I was trying to find a breakdown of emissions other than CO2 within your website. I used to be able to find them under Clean Air Pass. Any suggestions?

22. Comment by Adam Stein @ Aug 1, 2006 7 PM Comment permalink

How about Google? We’ve never sold anything called a Clean Air Pass, so you may be thinking of a different web site. TerraPass only remediates CO2, not other gases.

23. Comment by Wayne @ Aug 2, 2006 10 AM Comment permalink

Hello again. I found the info I was searching for concerning greenhouse gases and the Global Warming Potential. CO2 has a GWP of 1, CH4 (methane) has a GWP of 21, and N2O has a GWP of 310. Any comments?

24. Comment by Wayne @ Aug 4, 2006 10 AM Comment permalink

Please don’t misunderstand me, I’m just trying to do as much research into this as possible. I agree with the concept and am aware of other CX locations other than Chicago. However, I just tried your vehicle emissions test based on 15000 miles annually and I am of the opinion the results is grossly under estimated!!

25. Comment by Adam Stein @ Aug 4, 2006 10 AM Comment permalink

Hi Wayne,

I’m not 100% sure I’m following the question, but I think I can shed some light on what you’re asking. There are a number of greenhouse gases, including methane, NOX, etc., that are created when gasoline is burned. Often these are translated into their pounds of carbon dioxide equivalent (CO2e) based on their global warming potential. So, as you note, one pound of methane is treated as roughly 21 pounds of carbon dioxide from the perspective of environmental impact.

If you added up all the emissions from a gallon of gasoline and translated them to pounds of CO2e, it would bump up the amount of CO2 produced from roughly 20 lbs per gallon to somewhere in the mid-20s per gallon. Even though N2O has a much higher GWP than CO2, there is also much less of it created when you burn gas.

So I don’t believe our calculation is a gross underestimation. Another important point is that some of the other emissions vary considerably by car type, so it’s difficult to account for them in a consistent way.

26. Comment by Wayne @ Aug 4, 2006 3 PM Comment permalink

Thank-you for the clarification. I guess part of the inconsistencies is due in part to EPA and calibration of fuel economy is based on volume (density) not weight!

27. Comment by Anonymous @ Sep 2, 2006 3 AM Comment permalink

I’m still put off by the typical sound bite (and your headline). We are not creating matter. Opening with a fallacy does more harm than good by making the entire argument less credible. Personally, I think it is even more frightening to note that we are not only adding CO2 to the atmosphere, but using O2 in the process.

28. Comment by Adam Stein @ Sep 2, 2006 8 AM Comment permalink

Er, no one said anything about “creating matter.” Gasoline starts as liquid hydrocarbon and ends as a gaseous organic compound. The headline is perfectly factual.

Moreover, there’s no “argument” being made in this post whose credibility can be moved in one direction or the other. It’s a bit of stoichiometry — high school chemistry.

29. Comment by Martin @ Sep 6, 2006 5 AM Comment permalink

Just for fun, it would be interesting to calculate how much O2 gets removed from the atmosphere, and how much CO2 gets added, after all the recoverable oil in the Alberta Tar Sands has been burned by an average combustion engine (car).

Does CO2 level reach a poisonous level, is there enough O2 left to sustain human breathing?

For simplicity, I would assume we start with actual levels of concentration of O2 and CO2, and also assume combustion of gasoline is the only reaction (ignore other human and natural reactions like photosynthesis, carbon sequestration, etc.)

30. Comment by J @ Sep 7, 2006 6 PM Comment permalink

Hi. Interesting topic. Based on the volcanic CO2 emission questions, I wonder if you already have a link or chart showing the top 5 (10?) world wide contributors to atmospheric CO2 emissions per year?

On a related note, I was surprised that you reported that humans produce 150 times the CO2 as volcanoes (yearly)…is that primarily from cars? If not answered in the above Top-10 list, what are the top human CO2 producing activities (factories, breathing, etc.)? I had heard that all of the human CO2 emissions were only 5% of the total “global” CO2 emissions…is this the right percentage?

Many thanks in advance!

31. Comment by Adam Stein @ Sep 7, 2006 6 PM Comment permalink

Hi J,

No, human CO2 production is not primarily from cars. About one third of human CO2 emissions are from transportation, which includes planes. Most of the rest is created by electricity production for residential and commercial use.

- Adam

32. Comment by Tom Gold @ Sep 18, 2006 9 AM Comment permalink

Cars are, however the highest producer, so we should stop driving our stupid gasoline cars and make electric cars.

33. Comment by JB @ Oct 17, 2006 12 PM Comment permalink

The crazy thing about this is that the math is actually quite simple. Certain entities strive to confuse the general public in order to portray all the true critical thinkers as crackpots or idiots. I did some simple math on the C02 emmissions from electrical generation facilities. For each kWh generated, approximately 1 kg of C02 is emmitted. The US used approximately 3.8 trillion kWh in 2003. The result is staggering considering the fact that this stuff is pouring out 24/7/365 ad infinitum all over the world (not just in the U.S.). Detractors will take this and say I’ve got my numbers all wrong and ridicule me for trying to put it all in perspective. If all you have your mind on is profits, simple math becomes fuzzy for some reason or other.

34. Comment by Dick in Houston @ Nov 2, 2006 6 AM Comment permalink

It would be really interesting to me to see similar calculations for the entire barrel of oil from which the gasoline is refined. Each 42 gallon barrel yields (or so I am told) about 19-20 gallons of gasoline. The remaining 22-23 gallons is turned into furnace oil, diesel fuel, cleaning fluid, petrochemicals, pharmaceuticals and so forth. Is there any way to make an educated guess about the CO2 output from those?

35. Comment by Tom T @ Nov 5, 2006 6 AM Comment permalink

Another response to the cut all the trees down for the good of all people.
It seams that planting trees in all of those places that are already deforested might be a good start. There is much in the US and Europe that was once forest. So we wouldn’t have to calculate the carbon it would take to cut down all of those Amazonian trees, process them, and finally ship them to the world’s furniture deficient homeless. We could just start planting trees here.

36. Comment by Ru Hartwell @ Nov 30, 2006 11 AM Comment permalink

Great Stuff. We’ve come up with this idea of a ‘Sequestration Farm’. The trees are grown to maturity and then harvested into large baulks of timber and buried in the sea. In the anaerobic conditions down there the wood will last for literally thousands of years before relinquishing its Carbon back to the atmosphere. The brash can be turned into Biochar to lock its carbon into the soil long-term (Terra Preta) and the same plot of land replanted to begin the process again (ad infinitum). Basically what we are attempting to do is recreate the worlds stored fossil fuel reserves one tree at a time and in doing so re-absorb the 6 Gigaton surplus of carbon up there.

37. Comment by Enrique @ Dec 11, 2006 8 PM Comment permalink

Thank you so much on having this info. i will use it to respond to a non beleiver of global warming on the daily journal.


thanks again.

38. Comment by Anonymous @ Dec 15, 2006 12 PM Comment permalink

I must say that some of these “cut down the forests and replant them” need to consider a few other important factors:

First: Soils are not infinite resevoirs of nutrients. In particular, the Amazon soils are well-drained, nutrient poor soils. Plant life needs nutrients from decaying plant matter to grow. If you take that plant matter and turn it into furniture and/or put it at the bottom of the ocean, then you deplete the nutrients available for the next generation of trees. This means you can grow less trees per acre EACH TIME you cut and clear.

Second: New trees will not take in great quantities of CO2 for the first few years of life. Mature trees continue to sequester until dead, and should thus be spared the chainsaw. If the goal is purely sequestration, then the area occupied by the tree could be replanted.

Third: A healthy forest needs trees in various stages of succession. Other plants that form the understory (below canopy level) will struggle to grow in mono-culture, nutrient depleted forest stands, and thus the amount of CO2 you will be removing from the atmosphere is decreased.

I agree with the comment that we should focus on areas that are already deforested, rather than accelerating the rapid rate of current deforestment.

39. Comment by Ainslie @ Dec 18, 2006 9 AM Comment permalink

This is all really helpful, especially the last thinking about how we can think more critically about forestry and carbon sequestration.

I’m especially interested in data on C02 produced by coal-fired power plants per KWH. In northern Wyoming (as in other states such as PA, and globally, in the UK and China), near-surface coal is abundant. Many ranchers have been picking coal from road cuts and other places where coal seams are exposed for generations to heat their homes and shops.
I personally have a small Swedish coal burning stove; my back-up is the “Econoheat” electric wall panels, which are quite efficient compared to electric baseboard. So I’m wanting to compare C02 produced per Btu of heat - burning the coal directly in my home (which is new, well insulated, with south-facing windows, and small) vs. buying electricity from a coal-fired power plant for the heaters. If anyone can reccommend websites with relevant data, it would be helpful. I’m planning to contact the nearby mine that is the source for the assay info and our power company.
Ainslie

p.s. the dollar cost is a no-brainer: $40/ton; I use about 1/3 of a ton/month, so I’m heating my house for about $5/week! But this is the problem with most of the resources we use. The price does not reflect the true cost.
40. Comment by Question Consumption @ Dec 20, 2006 11 AM Comment permalink

This is a fantastic discussion and thank God it is finally happening. One thought that has not been discussed and is off topic, but I think noteworthy. Everyone should be looking at conservation in all its forms. There is a vast amount of CO2 generated (along with many other wasteful things) in everyday things that we (especially Americans)do thoughtlessly. How many people run the water while they brush their teeth? How many people have lights burning in rooms that they are not in? How many drive to the store when they could walk 2 blocks. Do you buy the name brand toilet paper because it is 60 cents cheaper then buying enviromentally friendly toilet paper ( seventh generation, etc). The list could go on and on. Start making conscious decisions based upon the impact, however small. Evaluate what you truly need versus what you want. Rebel against the excess consumerism this country has turned into. If you want to make a difference, START WITH YOU!

41. Comment by Woody @ Dec 29, 2006 8 AM Comment permalink

Yes, QC, there are large & small energy consumption issues everywhere in our culture. We need to attend to all of them since collectively they each become quite sugnificant.

This is off-topic but extremly important: the birth of one human being triggers ALL the energy & resource consumption of a lifetime. This effect multiplies because the progeny of one person (OK sticklers—2 people) continues or expands the consumptive process for an untold amount of time to come.

Keeping our own family size in check as well as supporting family planning charities has an incredibly far reaching effect on solving all kinds of problems, global warming being the most relevant here.

42. Comment by Claus Koenig @ Jan 3, 2007 1 PM Comment permalink

I ran this equation against the annual consumption of gasoline, which is 846 Million Tonnes. And that is 1.862 Trillion lbs. Now divided by 6.25 lbs/gallon of gasoline times 19.3 lbs / gallon of gasoline equals 5,747,385.6 Million Lbs of CO2 and 2,382,336 Million lbs of H2O steam. I hope I got it right, because those big numbers sound so unbelievable. The question is how many trees do you need to absorb all the CO2: According to some government agency in Canada 1 acre of healthy mature forest produces 22 lbs of O2 /tree /year or 8,800 lbs O2 / year. Then for 5,747,385.6 Million pounds of CO2 / year you need 474,990,545 acres of healthy mature forest. So we need 742,173 square miles of healthy mature forest. That can’t be right. And these are numbers from 2004 and only gasoline consumption. Please, prove me wrong!

43. Comment by Smith @ Jan 16, 2007 1 PM Comment permalink

Would there be a difference in carbon dioxide level emitted from a car exhaust if different grades of gas were used? (Example: would using the highest level octane gas (premium) emit more or less CO2 than lower level or regular gas??

44. Comment by Larry Grob @ Jan 17, 2007 1 PM Comment permalink

Adam:

I’m not going to bust your chops about math or metrics here. Just wanted to thank you for this informative post and its usefulness (to me at least) in helping eliminate what I’ve been perceiving to be a stumbling block for many people—the notion of the ‘weight’ attributable to gaseous emissions. I was able to ‘translate’ your message into a simplified (by scientific standards) visual model, and posted it on my blog, which is designed to filter the massive amounts of information on sustainability for those who are just finding their eConsciousness. Thanks again.

Larry Grob
www.theunlikelyactivist.com

45. Comment by Jamy B @ Jan 23, 2007 3 PM Comment permalink

I’ve recently spent hours trying to derive the results from this post by approximating the chemical composition of gasoline as a blend of n-heptane and iso-octane using the following stoichiometry:

C7H16 + 11 O2 → 7 CO2 + 8 H2O

2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

I used the following densities to set the mole fractions:

density of C7H16 at 20C = 683.76 g/L
density of C8H18 at 20C = 702.50 g/L

I assumed a blend of 87% octane to 13% heptane and came up with 18.04 # of CO2/gal of gasoline

Even if I go back and use 100% heptane or 100% octane, the results will still be ~18 #/gal

I’ve seen iso-octane listed at 691.90 g/L at 20C which again will not greatly effect the results.

This estimate does not include the reality that air and not pure O2 is being included as a reactant and that there will be unburned hydrocarbons in the products.

What is the real chemical composition of “gasoline”? And what did the WRI use to come up 19.564 #/gal?

46. Comment by Adam Stein @ Jan 23, 2007 3 PM Comment permalink

Hi, Jamy. I admire your dedication. The difference between your result for pure octane and our result for pure octane is due to the different weights we’re assuming for a gallon of gas. Doing the math on your densities, I come up with a weight of 5.86 lbs for a gallon of gas. As you can see above, I used a weight of 6.25 lbs, which I pulled off the web (no idea where at this point).

I can’t say what assumptions went into the WRI numbers. As you can see, the final result is sensitive to the inputs, although the results aren’t enormously different.

47. Comment by Anonymous @ Feb 14, 2007 10 PM Comment permalink

I love the way that you do your math (which i am not entirely sure is right)then conclude that 6 pounds of gas .25 pounds shy a reduction of 4% gives 20 pounds of co2 an increase of .7 pounds a 3.6% increase thus biasing your conclusion by ??% you work it out, i think 19 pounds is still interestin but it is not be to dramatic. I wouldn’t buy a car off you with those tactics especially if you were promoting its fuel effciency.

[Ed. note — our math is right. Also, we have no idea what you’re getting at.]

48. Comment by Anonymous @ Feb 15, 2007 2 PM Comment permalink

I found this info on the web, regarding the chemical composition of regular gasoline, but my source now eludes me. Unfortunately, these add up to 86.6% so there is 13.4% missing/unknown.

straight-chain alkanes - [octane 114.2285 g/mol]
17.3% by volume

branched alkanes - [iso-octane 114.229 g/mol]
32.0% by volume

cycloalkanes - [cyclohexane 84.16 g/mol]
5.0% by volume

olefins - Alkenes - [1-hexene 84.1608 g/mol]
1.8% by volume

aromatics - Benzene [C6H6]
30.5% by volume

ca. 19 pounds of CO2 emitted per gallon of gasoline combusted seems the most reasonable and accepted calculation available.

49. Comment by Berge Jay @ Feb 19, 2007 6 PM Comment permalink

This blog’s discussion is very informative. But the idea of purchasing carbon credits is a money making scheme. We, the population of the world need to change habits and use clean sources of energy. Changing habits requires putting money into environmentally friendly methods of producing the energy we need to live and make a living in a comfortable manor, not returning to the caves. I for one have put my money where my mouth is, Rather than buying questionable Terra pass or such, I have installed a 7200 kw PV system, changed most of my light bulbs to fluorescent, installed energy star appliances, and added insulation to the house. All that has cut my eclectic bill by about 40% and my fuel oil consumption by 60%. I live in NY.

50. Comment by Adam Stein @ Feb 20, 2007 1 PM Comment permalink

Hi Berge,

We think it’s great that you’ve taken all of these measures, and we certainly encourage all TerraPass members (and non-members) to take similar steps wherever possible. Solar panels are out of reach for many people, though, and so TerraPass provides an alternate way for people to, as you say, put their money where their mouth is by funding clean energy.

51. Comment by Alex_in_FL @ Feb 21, 2007 2 PM Comment permalink

Marc: Al Gore’s movie, An inconvienent truth is mainly myth - just like his book Earth in the Balance. Also, I like ponies.

Wayne:
GWP of water exceeds all of those, water is largest “greenhouse” gas (water vapor). Yes water is around for short time but we add it continuously so it is a factor.

Annon 48: Gasoline is primarily 6-12 carbon compounds. It includes Toluene, benzene, and many other fractions. Components vary by location and climate. Octane ratings are based upon Iso-octane = 100. But you can’t assume gasoline is 87 or 91% Iso-octane (or any two componds for density) as it is complex mixture.

Adam: Density of gasoline varies about 15% and 6.25 lb/gallon is reasonable number. 6 pounds of gasoline = 18.5 pounds of CO2 using your own numbers - not 20 pounds as you state. You round up on the CO2 and down on the lbs of gasoline and still are not right. (This is point annon 47 was making). The 19.564 comes out because gasoline is a complex mixture not single compound as your calculation assumes. Of course, the post actually goes into mind-numbing detail over the exact figures, so this sort of nitpicking is pointless, and I’m mostly just talking because I like the pretty sound I make when I do.

Regarding your more heat = more humidy = more global warming theory. Try this more logica one. More heat = more humidity = more percipitation = more snow = more snow cover = more light reflected = global cooling. So global warming might actually cause global cooling. Of course, that would only be true if scientific phenomena were explained by appeals to “logic”, and not, say, “empirical data.”

And yes (sorry forgot which poster) you are right, what actually happens is O2 is combined with the carbons to create CO2 so there is no mass creation just mass conversion.

Lastly, isn’t there already enough CO2 in the air to capture all the radiation being returned at the one point where CO2 absorbs but water does not?

Whew. Long but just remember, if we had begun combating global cooling in 1976 when all the scientist were in consensus that an ice age was coming we would be congratulating ourselves on success right now when in fact we did NOTHING to change the environment. When the model can explain the 30 year long cooling lasting until the early 1960s while CO2 was increasing I might begin to believe in this green house gas theory. I clearly am the first person to think of this, and all those clever climate scientists all across the world have somehow overlooked this blindingly obvious fact. What are the odds?

Ed. note — comment has been modified to make poster look silly.

52. Comment by Eric @ Feb 21, 2007 4 PM Comment permalink

Has anyone ever burned a gallon of gasoline, captured the emissions in a vacuum chamber, compressed the emissions down into a one gallon container and weighed it? This might get us the actual weight.

53. Comment by Observer @ Feb 23, 2007 2 PM Comment permalink

Interesting. Terrapass can not refute arguments by Alex_in_FL so they edit his post to belittle him? Does this mean that serious, accurate, fact based scientists are not welcome here? That the SOP is to ridicule when you can’t refute? He does make valid points (assuming validity counts).

Lastly, he has an interesting perspective in that global warming may cause global cooling. I think the huge snow storms of last week were attributed to global warming and more humidity hitting the cooler northern air thus causing record snow fall. Oh, wait, this does not support the party line so will my post be edited and ridiculed too?

54. Comment by Adam Stein @ Feb 23, 2007 2 PM Comment permalink

Um…these arguments have been refuted so many times by accurate, fact-based, scientists that they don’t deserve any attention. The SOP here is to engage in discussion with people who are interested in honest exchange of ideas, and to wring a few larfs out of those who aren’t.

55. Comment by Anonymous @ Mar 27, 2007 6 AM Comment permalink

Re #51 & 53:

H2O is limited in how much can stay as vapour: dependent on how much total water (ocean), the surface of that water, and the temperature of the air.

Until we significantly increase H2O production, we won’t see the water volume or surface increase any. So we can ignore anything other than H2O.

But there is already (you’ll agree) H2O in the atmosphere, so the change will not be a huge ammount (because that’s your argument for CO2 not being the answer). Excess H2O will not become vapour but will drip on to the floor as solid water.

So the increase in H2O doesn’t depend really on how much H2O we are adding.

Re: rounding down/up. There’s more than just petrol in a barrel of crude. Some of that gets burned. It still ends up being a doubling of weight burning oil to CO2. 42->84.

Lastly, there may be enough at the peak absorption of CO2 to trap all at that waelength. However, the FWHM bandwidth isn’t saturated for that, and that includes more energy radiated. Rovibrational bands that are small will still double and so on. So you may not see a doubling in the insulative effects when doubling CO2 but you will see a large increase.

All taken not as a scientist but as a physicist. Much as this article is merely maths.

56. Comment by Dennis Schmitz @ Apr 2, 2007 12 PM Comment permalink

CO2 has virtually no impact on temperatures. At approx. 350 parts per million CO2 is just a drop in the bucket. If I have a snowball consisting of 2850 snowflakes, and that snowball has a temperature of 25 degress, except for the one CO2 molecule with a temperature of 26 degrees, the one 26 degree molecule (CO2) will not change the temperature of the snowball from 25 degrees. Increase the CO2 molecule a few more degrees and still no change in the temperature of the snowball. And besides humans only contribute about 2.8 percent of total CO2 emitted into the atmosphere. The more research I do into global warming the more I see it is a hoax. Thanks, Dr. Storm

57. Comment by Tom Arnold @ Apr 2, 2007 2 PM Comment permalink

Yes folks, who do you believe. Dennis’ snowball analogy or 1000’s of peer reviewed publications?

CO2 has a dramatic and well understood radiative forcing function.

Tom

58. Comment by Dennis Schmitz @ Apr 3, 2007 7 AM Comment permalink

I’m just trying to put this into perspective. At 350 parts per million (1 part per every 2850) what temperature must the CO2 molecule be to raise the other 2849 molecules one degree F? I understand the radiative forcing, but would like to see an actual numbers here.

59. Comment by Tom Arnold @ Apr 3, 2007 7 AM Comment permalink

Dennis: That’s a totally legitimate question.

As measured by the IPCC, the radiative forcing effect of CO2 in the atmosphere is 1.46 Watt/sq meter.

Read more here: http://en.wikipedia.org/wiki/Greenhouse_gases

And for a very nifty graph showing the contributions (both positive and negative) of different gases: http://en.wikipedia.org/wiki/Image:Radiative-forcings.svg

60. Comment by Adam Stein @ Apr 3, 2007 3 PM Comment permalink

One kinda funny thing is that Dennis isn’t just questioning (anthropogenic) global warming — he’s actually questioning whether there’s any such thing as the greenhouse effect. At 350 ppm, he says, CO2 can’t have an effect on global temperature.

But without CO2 in the atmosphere, the earth would be an ice ball, with an average surface temperature of -18° C.

Disputing the existence of the greenhouse effect would take denialism in exciting new directions. The greenhouse effect is basic science, about as controversial as the existence of gravity.

61. Comment by Dennis Schmitz @ Apr 4, 2007 6 AM Comment permalink

I am not disputing the greenhouse effect. You claim without CO2 the earth’s temperature would be -18 degrees C. That is incorrect. Without a greenhouse effect at all the temperature would be minus 18C. Water vapor accounts for more than 95% of the greenhouse effect. It is a fact that CO2 rises when temperature rises and not the opposite. CO2 has no effect on global temperatures. It is a good idea to get information concerning this subject outside the IPCC. If CO2 is a great heat trapping gas, then it would have to be a poor heat radiating gas. As I stated previously, CO2 is one part per every 2850, and would not be able to increase the temperature of the other 2800 plus air molecules. The “sun” is what is driving the current minor increase in global temperatures, not CO2.

62. Comment by AH @ Apr 4, 2007 6 AM Comment permalink

Dennis’s question stems from an incorrect understanding of how the greenhouse effect works. The CO2 is at exactly the same temperature as the surrounding gas (25C in his example). What happens is that it interferes with the radiation of heat from the earth’s surface into space. The extent of this interference is a function of how many CO2 molecules there are per unit volume and is actually (nearly) independent of how many other molecules of oxygen, nitrogen or other gases there are (of course, some other molecules like methane and H2O have similar effects, though of different magnitudes).

63. Comment by AH @ Apr 4, 2007 6 AM Comment permalink

Since we seem to have posted at essentially the same time, I’ll add that the IPCC is not just one among many competing interest groups, but is open to the entire scientific community worldwide. To be outside the IPCC is in essence to not be engaged in scientific study of global warming.

64. Comment by Adam Stein @ Apr 4, 2007 7 AM Comment permalink

I can’t believe I’m responding to this baiting, but this topic is actually kind of fun…

Dennis, you are correct that the greenhouse effect is caused by a number of gases. You are incorrect that CO2 is not one of them. As for the IPCC, I think you’re actually referring to the IPCC report, which, as AH notes, is authored via an open process that encompasses all of mainstream climate research.

But just for fun, let’s step outside the confines of the IPCC. A lot of foundational work on the temperature effects of CO2 was done by Svante Arrhenius, who won the Nobel Prize for chemistry…in 1903. Although many of his calculations were later shown to be flawed, his estimate that a doubling in atmospheric CO2 levels would lead to a 4 - 6°C rise in global temperature is remarkably close to the predictions of modern climate models. Not bad for a guy who had to do the math by hand.

Again, you’re arguing against the existence of gravity. The notion that a concentration of 350 ppm is too small to matter is, well, rather eccentric. There is no magic ratio below which chemicals stop having an effect.

65. Comment by tbg @ Apr 4, 2007 3 PM Comment permalink

I’ve never delved into the TerraPass blog before, and let me say - it is a wonder. This particular post and resulting discussion are particularly helpful to me, since I feel like so much of the time we take global climate change for granted that we forget to keep explaining some of the simpler math. [aside: your argument, Alex_in_FL, is precisely why I use the term global climate change or climate instability rather than just “warming,” since there are already all sorts of observed weather patterns that are a whole lot more than just extra degrees] I’ve really enjoyed most of the posts, especially the skeptics, since the responses to those help me formuate my responses when I am working with these issues (particularly posts like Dennis, since I wouldn’t have even seen that one coming!). Thanks!

66. Comment by Dennis Schmitz @ Apr 5, 2007 6 AM Comment permalink

I must say I am developiing a much more open mind to this subject. To AH’s response, #62, if the CO2 molecule is the same temperature as surronding gases, then how does this interference idea work? My understanding was the CO2 molecule would lose heat at a much slower rate than the other surronding air molecules (hence heat trapping gas). Thanks, Dennis

67. Comment by Dennis Schmitz @ Apr 5, 2007 6 AM Comment permalink

I guess I should double check my spelling before posting. 3 typos, developing, surrounding and surround. Sorry, Dennis

68. Comment by Ryan @ Apr 9, 2007 10 PM Comment permalink

Dennis:

I do not claim to be an expert on this subject but I am working towards my Ph.D in atmospheric chemistry. The question you are asking delves into some quantum mechanics.

Starting at the basics it is important to understand what makes a greenhouse gas a greenhouse gas. Above all else the molecule must be infrared active. This means that IR radiation causes the molecule to go through either rotational or vibrational transitions (i.e. the molecule starts to vibrate/rotate/bend/stretch along its bonds). In order for this to happen the molecule must have a dipole moment or be able to have an induced dipole moment. This is why water vapor and CO2 are such goo greenhouse gases. Water has a permanent dipole moment and CO2 can have an induced dipole moment (the oxygens on either side of the carbon can start to stretch back and forth and bend up and down). Molecular oxygen and nitrogen on the other hand cannot and do not have dipoles so therefore cannot be greenhouse gases.

To make a long lecture short and in the essence of not confusing you more than you already may be, the molecule will absorb the IR radiation and then reemit it in the form of thermal radiation. This is then reabsorbed by the earth making it warmer still. So the interference idea is not that CO2 gains or loses HEAT but it does have a change in ENERGY that is converted into heat by the earth’s surface. And answering your main question (finally) it is not that CO2 loses heat more slowly than the surrounding air, it is just that the majority of air (nitrogen and oxygen) can’t interact with IR radiation and do not have the means to be greenhouse gases due to the reasons described above. It has nothing to do with heat retention and everything to do with a molecule’s dipole moment and energy transitions and some other stuff.

Again, this is a gross over simplification in order to make it semi understandable to people not having taken quantum chemistry and physical chemistry courses. I only hope I have not confused you more. But just understand that this phenomenon is not some theory made up by liberal propagandists, it is real science that has been observed in labs for decades.

To anyone who can describe this better, please do so.

Dennis: For your own benefit it may be worth while to look up black body radiance of the earth and how greenhouse gasses effect it.

69. Comment by Eric @ Apr 11, 2007 6 AM Comment permalink

I agree that CO2 is harmful, emissions need to be reduced, miles per gallon need to be increased, and so on.

However:

The title says six pounds of gasoline make twenty pounds of carbon dioxide. That isn’t true, and it isn’t even supported by the information given.

The contents of the article say that MORE than six pounds (6.25) of gasoline make LESS than 20 pounds (19.3) of CO2.

[Ed. — man, this article attracts pedants like flies to honey. As the commenter notes, the information given in this article is excruciatingly accurate and clear. And the headline also uses accurate rounded values: 6.25 —> 6, 19.564 —> 20.]

70. Comment by Dennis Schmitz @ Apr 11, 2007 2 PM Comment permalink

Thanks Ryan for the information. This got me thinking about how CO2 warms the surface. It seems possible that CO2 could also cool the surface. Let’s say in the artic in winter (no solar heating) the ice (surface) temperature is zero degrees. Now an air mass moves in at 50 degrees below zero. The CO2 now reemits thermal heat so to speak, which is minus 50 degrees, therefore cooling the surface further, cooling the air temperature further. I guess this would be as the air temperatures tries to modify the CO2 keeps modification from occuring. Possible? Thanks, Dennis

71. Comment by Ryan @ Apr 11, 2007 6 PM Comment permalink

Hey Dennis

I think I see what your question is. In order for the air mass to do what you are asking it must be constantly emitting thermal radiation (radiation not heat). But this is not the case; the reemitting of the thermal radiation is a one time deal-it only happens nearly immediately when the gas interacts with the incoming infrared radiation and it will not store any of this energy to be reemitted at a later time.

So let me explain again in a more coherent way how the greenhouse process works (last time I don’t think I did a good job). When light (electromagnetic radiation) comes in through the earth’s atmosphere it is of a relatively short wavelength and carbon dioxide and other gases cannot absorb it. But the earth is a black body and can absorb all wavelengths so the earth absorbs the short wavelengths and then reemits the radiation at a longer wavelength. This longer wavelength can then be absorbed by the greenhouse gases which in turn reemit the radiation back to earth where they can heat things up again. It is like the game of pong, the radiation goes back and forth between the gases and earth until it escapes. The whole time it is bouncing around it is constantly heating up whatever absorbs it.

So in short if there is no sun as in the arctic winter, there is no radiation to be emitted back and forth. The carbon dioxide does not retain this thermal radiation, just like a mirror does not retain images after the bathroom light is shut off. There has to be light to be reflected.

What would actually happen in the case of the colder air than on the ground is the ground would get colder (slightly) but the air would get warmer (more dramatically). They would come into “thermal equilibrium” with each other but this has nothing to do with greenhouse gases it is one of the laws of thermodynamics. The ground would transfer heat to the air but the air would not transfer cold to the ground.

I get the feeling that I am not a very good teacher but I hope I am doing you more good than bad. Its good to see that you are curious about this stuff and ask questions rater than thinking everything is a hoax! Don’t feel bad if it does not make a whole lot of sense. I could spend hours in person with someone going over this stuff, but in this setting it is just not possible.

72. Comment by Anonymous @ Apr 29, 2007 10 AM Comment permalink

Please list the 5 major “greenhouse gases” in order of highest concentration to lowest.

If greenhouse gases are “causing” the 1 degree C increase that the earth has experienced in the last 100 years, then please point me to the data that shows that the temperature of the troposphere is increasing faster than the surface temperature of the earth.

If it isn’t really the concentration of “greenhouse gases” which cause the temperature of the earth to increase but it is actually the concentration of CO2 (due to a higher rate of magic-ness than methane or water vapor) why did the earth’s temperature decrease from 1940’s-1970’s when the concentration of CO2 continued to increase as the post WWII industrial revolution dumped tons of CO2 into the atmosphere?

73. Comment by neil @ May 5, 2007 2 PM Comment permalink

RE: cutting trees & forests because old trees do not sequester carbon -

the latest science is starting to show that this is not completely true. recent research out of Europe & China indicates that old-growth forests can store atmospheric carbon. a survey of forest biomass [carbon] around the world show higher amounts of biomass [carbon] in the older temperate forests.

the notion that old trees and forests are ‘dying of old age’ was actually show to be somewhat ridiculous in 1927 by Bob Marshall in the Journal of Forestry “Influence of precipitation cycles on forestry”. Why the idea that we need to cut forests to reinvigorate them has persisted for so long is beyond me.

74. Comment by Dennis @ May 15, 2007 12 PM Comment permalink

As I continue to do research on global warming, I find so many misconceptions. For one, CO2 absorbs all the available IR at very low concentrations, therefore the amount of heating CO2 is responsible for occurs at very low concentrations. Imagine a 1” square column or tube of air from the surface up to 4000 meters (height where CO2 official measurements are taken) and the amount of CO2 in that area. There are billions of CO2 molecules in that column, and at a very low altitude all the IR is absorbed. Add more CO2, the altitude at which all IR is absorbed lowers, thus no additional heating occurs.
This is science, pure and simple. Therefore CO2 is a heat trapping gas, but has done all it is capable of at a far lower concentration than todays 383 ppm.

[Ed. — nope. This is a common fallacy. See here and here for how this really works.]

75. Comment by Darryl @ Jun 4, 2007 12 PM Comment permalink

Ed. — comment deleted.

Oh, Darryl, this was just such a sad showing. You wrote to us with a hostile and ignorant question, and we did you the favor of responding with helpful and factually correct information.

And you thanked us by scrawling graffiti on our web site. What motivates this kind of smallmindedness?

76. Comment by Sam Schock @ Jul 30, 2007 10 AM Comment permalink

During my lifetime this planet population has more than tripled thereby creating humongous demand on the planets resources.

The greenhouse effect of C02: fact or fiction? The facts are that planet earth exists in a near perfect vacuum; outer space is reported to consist of 6 to 8 hydrogen atoms per cubic meter which can't radiate heat into outer space where it is plenty cold; PLANET EARTH EXISTS IN A NEAR PERFECT VACUUM.

Heat reaches planet earth in the form of a ultra-violet rays from our sun; the ultra-violet rays from the sun makes possible the vegetation on planet earth, which converts the locked oxygen in the earth into atmospheric oxygen, while it scrubs carbon from the atmosphere and locks it into fibrous vegetation; it's a chemistry that only GOD could create. Where the ultra-violet rays hit surfaces other than vegetation, it is transformed into radiant heat which radiates from atom to atom in whatever; HEAT, ONCE GENERATED, CANNOT BE NUTRALIZED, IT TADIATES OUTWARD INTO THE ENVIRONMENT; INT EH ATMOSPHERE IT IS FROM OXYGEN ATOMS TO NITROGEN ATOMS; IN OUR WATERS IT IS FROM OXYGEN ATOMS TO HYDROGEN ATOMS; IN TEH CASE OF MATTER AND METALS IT RADIATES FROM ATOM TO ATOM OF WHATEVER.

Significant changes to this chemistry has been as a result of human activity; as we cut down the forests we alter GOD'S intended chemistry; fluoro-carbons have resulted in the destruction of upper atmosphere ozone; while our use of hydro-carbons have increase ground level ozone.

Global warming is a fact as a result of human activity; the Greenland ice-caps attests to that; all the electrical power generating plants are water cooled, including the nuclear power plants; and all that cooling water which has been warmed by the power generating plants ends up in a stream, river, lake and finally in the Atlantic Ocean off the east coast of North America, it gets picked up by the Gulf Stream which flows northward hitting Greenland head-on, and we are witnessing the melt-down of the Greenland ice-cap.

If you believe that you are saving planet earth by buying a hybrid vehicle you are being deceived; that electric powered motor generates heat which is dissipated into the atmosphere, into the environment; AND HEAT, ONCE GENERATED, IS THEREFORE FOREVER AND A DAY. Put your hand on an electrical motor after running it a few moments and you can feel the heat.

The foregone explains the mechanics of HEAT; global warming has little to do with C02 the heat that we generate on planet earth (and we generate a lot of it) can't go anywhere in a vacuum.

the gasses that are being flared daily by the oil industry is an outright sin; then the scientists came up with the catalytic converter which was to be the solution to the C02 problem ( that's a real heat generator) , the technology is there to do a reasonably clean burning internal combustion engine, but it all involves heat and how one uses it.

When I was till driving cars I could get them to run on 30% less gasoline than was the factory delivery; when I pulled the spark-plugs they were a light tan in color, clean; no carbon build up. As of 1990 the automotive industry has done their best to get rid of hte back yard auto mechanics; and govt's have bought into it hook, line, and sinker.

The automotive industry has the stoechimetric hang-up; some nit-wit (scientist) determined that it required 8999 liters of air to burn 1 liter of gasoline: THAT IS JUST PLAIN BULL. The technology is there to more than double the current gasoline mileage, which mean that there is less heat output for every mile that is being driven.

C02 is a minor element in global warming; the real culprit is the HEAT being released into the environment; it cannot radiate into the vacuum of space. Had God meant for man to fly He would have created man with wings. With all the computers that we have should we be able to calculate the BTU’s is spewed into he environment daily. The heat that we produce on planet earth will not radiate outward into the vacuum of space.

77. Comment by Adam Stein @ Jul 30, 2007 10 AM Comment permalink

Sam — awesome comment. Totally, completely wrong, but awesome nonetheless.

The heat radiation from manmade energy production is a minor rounding error compared to the energy that hits us from the sun. What’s the old factoid — the sunlight that hits us in a single hour is enough to meet the world’s energy needs for an entire year? Something like that. So it really is the combination of greenhouse gases and solar radiation that drives the global temperature balance.

78. Comment by Anonymous @ Aug 7, 2007 11 AM Comment permalink

Adam, thanks for the interesting and informative article. This is something I’ve been wondering about for a while now.

I do have an issue with the math however. The atomic weight of carbon is 6, not 12. Also, the atomic weight of oxygen is 8 and one of your calculations uses 16 (O2 is 2 x 8, not 2 x 16). Here are the numbers I calculate:

C8H18 - 6*8 + 1*18 = 66
CO2 - 6 + 8*2 = 22

One C8H18 molecule produces 8 CO2 so the ratio is 8 * 22 / 66 = 2.67. Multiply by the 6.25 weight of a gallon of gas gives only 16.7 lbs. of CO2.

This doesn’t change the explanation of why there can be a roughly threefold increase in weight, but does show, I suspect, that the calculations are much more complex than shown here.

79. Comment by Adam Stein @ Aug 7, 2007 4 PM Comment permalink

Hi Anon,

Glad you like the article. You’re mixing up atomic number and atomic weight, though. Atomic number is the number of protons in each atom, and you’re right that the atomic numbers of carbon and oxygen are 6 and 8 respectively. But atomic weight also includes neutrons, and the weights of carbon and oxygen are 12 and 16.

- Adam

80. Comment by Sam Schock @ Aug 9, 2007 10 AM Comment permalink

WOW! I did get a live one. “Totally, completely wrong, but awesome nonetheless.” I don’t see any difference between planet earth being bottled up in a greenhouse and being bottled up in the vacuum of that which is defined as outer space; the heat which is generated by the sun, and that which man generates by his use of fossil fuels can’t get out of your greenhouse, or my planet earth into the vacuum of space. The heat input via ultra-violet rays of the sun are much the same today as they have been for centuries. Planet earth has experienced climatic variances over the ages; but as of the industrial age the average mien world temperature has been on the increase, really going up the scale as of World War II; the petrol which fueled World War II came out of British and German coalmines; I would know as I was there. I could suggest a solution; you might try artifical clouds; smokescreans at elevations of 50 to 100 miles altitude; now that I think of it, it might not be such a good idea, it may just stay up there and your stuck with it. Ever notice how a heavy cloud can block out the sun and you have a 10 degree Cen. temperature drop in a matter of minutes. God reportedly shielded the Israelites under a cloud to protect them from the heat of the Siani Desert sun and heat for forty years. There is no question that global warming is the result of human activity, and if we don’t change our economic system real quick it’s going to get hot, hot, hot. I can visualize your response, AWESOME, AWESOME. I grew up with the evolution of the internal combustion engine; I had a Willy’s Jeep for 2 years, 4 months during the war; the only servicing that it had I did; I know what makes an engine run; when I was driving cars I bought the Chev in-line 6 cylinder with the power-glide transmission; in 7 tenths of a mile I would be at 110 MPH; my cruising speed was 85 to 90; I had 2 speeding tickets in Canada, both speed traps; I pulled up 4 times in the US, telling them that I always drove this speed; they just warned me; 15 minutes later I was up to speed; my tach would be at 2800 RPM; 3600 rpm at 110 MPH. Have you ever driven 1160 miles in 21hrs. 15min? Marathon, Ont., to Kipling, Sask. I fueled and had breakfast, the washroom at Thunder Bay a time-zone change, I fueled, lunched, the washroom at Dryden, I fueled, lunched, the washroom at Winnipeg, the time-zone change was the Man. / Sask. boarder, and I was in Kipling, Sask. at 10:30 PM.; I had to slow down some for a lot of villages along the way. I was driving cars that were twice the weight of the cars of today. 150 t0 200 miles per Imp. gal. are possible if one does it my way. I once boarded with 3 RCMP officers at Cranbrook, BC., one had a Cobra, every day at breakfast and supper time he would give us the Cobra THING, one Saturday he was polishing it as I sat on the steps of the boarding place; he asked, did I want a ride? We went out of town to a straight stretch of road; we were a bit over a mile before he passed the 100 MPH mark, when we got back I asked if he wanted a ride in my car; I went to the same startup point; in 7 tenths of a mile we were at 110 MPH., when we got back he wanted to see what it was that I had under the hood; when he saw an in line 6 cylinder he just walked away; he never talked about the Cobra again so long as I was there. I got my education by getting my hands dirty; the closest that I came to a university was 3 months at RCMC at Kingston, Ont., I had to learn and learn it fast. The automotive costumer is being had; BIG TIME. Some of us oldtimers have knowhow that you don’t get at a university. Everybody is touting electrical energy as the way to go; nitrogen is used to cool the electrical generaters at the Grand Coule Dam, I expect the same is the case with all mega-watt generaters; even your windpower generater is producing BTU’s as it generates electrical power, and as you use that electrical energy it is producing BTU’s, all of which radiate outward to be trapped forever in your greenhouse, my vacuum bottle. Start counting the BTU’s instead of the CO2. The heat that we generate on planet earth will not radiate outward into the vacuum of outer space because it requires an association of atoms, molecules, to transfer the heat. TRULY AWESOME INDEED. To reduce your CO2 levels you would have to cease using fossil all together, which is not likely. I obviously did get the attention of one party, which was in the negetive; I would expect this commentary to initiate a fullblown debate. There are ways in which we can use the sun to eliminate the production of CO2, which produces BTU’s which perform work; to heat our housing. When you go to your fridge to get a cold beer you are using BTU’s and producing CO2; both events are going on as you sleep. Should somebody out there have one of those CO2 scales on the cheap I would like to buy it; I just can’t get my head around the alchemy of converting 1 kg. of gasoline into 3.25 kg’s. of CO2 thereabouts. Has anybody thought of using water in conjunction with fossil fuels as a fuel? The prairie homesteaders used water in their kerosene fueled Rumley-oil-pulls, the airforce used water during World War II at take-offs, the RCAF used water in their Aurora’s used on Pacific Coast patrol; I believe the technology is there to do just that; you could reduce the CO2 output and still get the BTU’s; it is the BTU’S that do the work; push the aircraft through the air, roll the vehicle along the highway; it is the BTU’s that contribute to global warming. It will be 71 yrs. at the end of this month, August 2007 when we came into Calgary from the east at about 9:30 AM, the atmosphere was clear, we could see the snow capped mountains in the west; twenty years ago they were still visible; today, August 3/07 I was on the LRT going to the northeast, the atmosphere was clear, the sun was bright, not a cloud in the sky, it was 10:00 AM., Calgary was souped in, no mountain view. The only time that one can see the mountains these days is when there is a good stiff breeze from the west, and all you will see are parches of snow on the north face of a mountain. There are two sides to a coin, two sides to a debate; the ultra-violet rays comming from the sun are much the same as they have been for centuries; it is human activity which has triggered global warming. It requuires four times more BTU’s to move a car at 40 MPH than it does at 20 MPH. The faster that one goes the more BTU’s required. How many BTU’s will be put into the atmosphere, environment, at the Montreal NASCAR race? If CO2 is indeed the culprit, you should have cut back on its production decades ago. Mankind has to realize that if it is to survive it has to slow down period. When I hear politicians talking about hydrogen highways I can’t help but be amused; hydrogen isn’t like water; where did they get their education; one does not pick hydrogen off apple trees; one can’t even store it for any length of time in a steel bottle, it will leak through steel; note the refrigeration required by the American space shuttle; ethanol and biofuels are touted as being the solution to CO2 output; work, is the result of BTU’s no matter what the fuel. Your global warming is a real conundrum; ABSOLUTELY AWESOME INDEED. Totally, completely wrong ?? ??? I’ve been shot at for real, I hit the dirt, makes one a smaller target and you survive to continue the fiight. In my last presentation I noted that the automotive industry had determined that the ideal fuel / air ratio would be 8999 litres of air for every litre of gasoline; that works out to a little better than 1 cubic mm of gasoline per litre of air; as air is slightly more than one fifth oxygen, the gas which facilitates the burn of the gasoline, the nitrogen contributes nothing to the burn; the industry has used high compression to achieve the gasifying of the gasoline in order that it would burn more efficiently; the industry has resorted to the small bore, short stroke, and high RPM; gasoline, any fuel requires time to burn and do its worlk, diesel has a slower burn rate than does gasoline; the Chev in-line 6 cylinders that I drove had a compression ratio of 8.5 to 1; I down-sized the main metering jet; plus another thing that I did, the entire operation didn’t require more than an hour and a half; I improved my gasoline mileage by 30% over the factory delivery; I could get to 110 MPH in 7 tenths of a mile, that was fast enough for me, I didn’t want a tire to blow at the speeds that I was driving, the tires would be replaced once I got down to a quarter inch of tread. I had more than enough power to get me from point A to point B with exceptionally good gas mileage for the weight of the vehicle. When I say that 150 to 200 miles per Imp. gallon of gasoline are there I’m not kidding. You wouldn’t believe how simple an engine can be. The technology is there and I know where to get it. The engine that I propose would be substantially less costly to manufacture and operate. Burn the gasoline in the combustion chamber, not in the catalytic converter, get more work out of the BTU’s by reducing those going to waste into the environment. A diesel specialist told me that he could cut a cubic mm. of diesel into 50 injections, at 26000 psi. injection pressure you get the vaporization to get a clean burn; the same can be the case with gasoline. I have some of the parts for the engine at a machine shop, other parts are wherever, it’s an engine that is so simple that there are no blueprints; the way they did it in the good old days. The only guy that has made any money out of the hyrdogen economy is a guy named Ballard; it’s years ago that he was driving a hydrogen bus around Vancouver, Chicago, and wherever else. I once had a Chrysler product, a Fargo truck, when they still had 6 volt electrical systems; they were notorious for being hard to start, I took it to the garage and told the mechanic that we would change everything to 12 volts other than the starter; he told me that it wouldn’t work; I told him that it was my money, the total cost was a few dollars short of 100 dollars, we left the 6 volt starter in place as well as the heater; I had no more starting problems, the second time that the crankshaft came around the engine was running; 13 years later that 6 volt starter was still cranking the engine, and the heater heating the cab. Gasoline is still the way to go; one can more than double the gasoline mileage of the current vehicles on the market; my proto-type is crude, not a production product, in as little as 4 to 6 weeks the assembly could be completed, ready for the dynamometer, check out it’s CO2 output. Over my lifetime I have operated a variety of equipment with a variety of engines, most of which had a quirk of some sort, once you figured it out you fixed it, lived with it, or you got rid of the bummer; each situation was a hands on learning experience; there have been a lot of people in the manufacture of the internal combustion engine over the course of my lifetime; I’ve been there for the evolution of the internal combustion engine. Go to a magazine stand and you can pick up numerous magazines advertising numerous means by which to increase the horsepower; the Chev. in-line 6 cylinder had all the horsepower that I ever needed. It’s time for the world to slow down. That hydrogen highway is so far fetched that I can’t believe that anybody with a university education to be buying into it. As already noted, I can’t get my head around the alchemy of getting 3.25 kg’s. of CO2 thereabouts out of one kg. of gasoline. My intellectual knowhow has to be worth something. THAT HYDROGEN HIGHWAY WOULD BE AWESOME INDEED. Your sure that there would be no oxides coming out of the exhaust pipe?? ???? How about nitrogen oxides?? ???? Get the magazine; ENGINE MASTERS, the spring 2007 issue; Who needs 1060 horse power?

81. Comment by nmanhipot @ Aug 27, 2007 8 AM Comment permalink

Would you mind explaining to me how buying carbon credits will help the environment? If I’m Al Gore and I have a house that uses 20-something times the amount of energy as the average American energy hog’s house, I jet around the world and am driven around the country in an armored motorcade and then make a mega-bucks donation to eco-friendly endeavors, how am I saving the planet from global warming?

As for me, I ride my bicycle to work and in the past 8-months I have OFFSET 233.913 gallons of petrol and 4576.28 pounds of CO2. So who’s doing the real offsetting here, me or Al? And, yes, I’m accurate to 6 digits because I care.

82. Comment by Sam Schock @ Sep 10, 2007 9 AM Comment permalink

Further to the greenhouse debate. I wasted three hours at the Calgary main library; they didn’t have as much information as I have at home. In 1963 I flew east; Regina to Winnipeg was the prop job Vanguard; at Winnipeg I boarded one of Air Canada’s DC8’s the jet-powered job; there was a one hour delay because they had to change the starter on one of the engines; when we finally did get under way we went to the end of the runway, they set the brakes and powered up the engines, all four; when they released the brakes there was no way that I was going to get out of the seat because of the G-forces; within 400 yards we were off the ground, and the nose was up until we leveled off at 41,000 ft.; we were above the clouds, and the sunlight was the brightest that I’ve ever seen, the top of the clouds were the whitest that one will ever see; I wouldn’t think of even attempting a glance at the sun for fear of eye damage. What’s my point? I didn’t see no greenhouse cover. The flight crew did give us the outside temperature; which I can’t recall, other than that it was cold, cold, cold. One reference notes that the ozone zone is from 6.2 miles to 50 miles altitude, it is densest at altitudes of 13 to 16 miles, [21 to 26 km]. We were at an altitude of 7.75 miles, which had us in the ozone zone; those four jet engines were ingesting quite a cocktail of ozone, and nitrogen oxides are not ozone friendly; and the jet engines put out lots of nitrogen oxides. The literature notes that, “airline pilots prefer to fly in the stratosphere to avoid weather disturbances in the troposphere. The stratosphere usualy has a lower layer of nearly steady temperature and an upper layer in which temperature increase with altitude. The temperature of the lower layer is about minus 67 degrees F, [minus 55 degrees C]. The temperature of the upper layer increases to about 28 degrees F, [minus 2 degrees C] at the top of the stratosphere. The stratosphere contains most of the atmospheres ozone. Ozone heats the air by absorbing the sun’s ultraviolet rays.” We were at 41,000 ft. and had to belt up for a time because of air turbulence; so, how high are they flying? “The mesosphere extends from the stratopause to about 50 miles, [80 kilometers] above the earth.The temperature of the mesosphere decreases with altitude.The lowest temperature in the earth’s atmosphere occur at the top of the mesosphere, called the mesopause. At the mesopause over the poles, the air temperature as low as minus 171 degrees F, [minus 113 degrees C] during the summer. Trails of hot gasses left by the meteors can be seen in the mesosphere. Extremely strong wind bow in this layer.” We arrived at Toronto on schedule, at one time the ground speed was reported at 730 MPH. I should note that we were flying light; the passenger load would have been 12 to 15 %. NOW, lets go back to the days of atmospheric nuclear tests; the Americans and the French did extensive nuclear atmospheric tests in the southern hemisphere where we have the larger ozone hole; The USSR did their nuclear tests in the northern hemisphere where we have a smaller ozone hole because of a lesser number of tests. Because of the worldwide fallout of strontium 90 and cesium, the two superpowers of the time implemented the Atmospheric Nuclear Test Ban Treaty. It wasn’t until the 1970’s that scientists dicovered the ozone holes, after the atmospheric nuclear tests. I, can only presume that the atmospheric nuclear tests put the holes in the ozone layer. I have no idea as to how many space launches there have been; I would expect that by now it would number in the thousands; and everytime that a space launch goes through the ozone layer, it is taking out some of the ozone protection of planet earth. Carl Rutan launched a space vehicle to a height of 62 miles, well through the ozone layer resulting in ozone depletion; and there is talk of making it an entertainment event; a thrill seekers business. Has man taken leave of his senses? My literature shows nitrogen oxides and carbon dioxide at a specfic gravity greater than 1.5 at the atmospheric pressure of 14.7 psia., and a temperature of 68 Fahrenheit, relative to 1 for air under the same conditions; which would tend to keep it at ground level; not up there, wherever. A news item had the scientists predicting that in fifty years there would be half the polar bears than at present; I have news for you, this world will be much different from that which we have today. The Holy Bible is the worlds greatest text book; the worlds greatest teacher, the Lord Jesus Christ tells us that but for his intervention on behalf of the ellect; “And except those days should be shortened, there should no flesh be saved: but for the elect’s sake those days shall be shortened;” which no doubt includes the polar bears, the elephants, the human species, and whatever else. The human species, a supposed evolution of the ape family, has by now invented the means and mechanisms by which all life on planet earth can be terminated. The last time I checked the apes were still apes and doing their thing. To this point, nothing on BTU’s. When we eat more calories, [BTU’s], than required to keep us alive we have to work them off or they are stored as fat; obviously much of our society is over-indulging, gluttonous, eating to much. All our lives we exhale carbon dioxide and radiate the BTU’s that we do not require. Once we went mechanical we overwhelmed the environment with BTU’s and when it goes on for 24/7 for decades we have global warming. Combine our output of BTU’s with the ongoing destruction of the ozone-layer and we get; GLOBAL WARMING, IT’S GOING TO GET HOT, HOT, HOT. It’s time for the scientists to take a look at something other than the GREENHOUSE SONG BOOK, it’s to simplistic. Carbon dioixide is the end product of the production of BTU’s; if we all went to bed AS we were meant to, turned out the lights; we would be cutting back on GLOBAL WARMING. One need not be a scientist or engineer with a Ph.D to figure out the problem; this is something a high school graduate should be able to figure out. I believe that I have contributed all that I’m going to contribute to the GREENHOUSE DEBATE; if carbon dioxide is part of the equation it is minimal relative to the other factors pointed out. If you don’t ground the aircraft industry, GOD WILL; and that could be soon. ADIOS AMIGOS.

83. Comment by Braven @ Sep 18, 2007 8 PM Comment permalink

I’m writing a paper for my critical thinking class and would like to use a comment you made about the CO2 produced by 1 gallon of gas being enough to fill the cargo capacity of 2 Ford Explorers. Would you allow this?
Also I’ve searched the site and can not find a bio on you. If I may be so bold, what are your credentials? Please be so kind as to copy any return message to my email address above. I’m not so sure I’ll remember to check your site again in-time.
Thank you.

84. Comment by Adam Stein @ Sep 18, 2007 8 PM