The REAL numbers on carbon emissions for my car.

You’re sitting there. Idling in traffic. Stop. Go. Stop. Talk radio’s on. Cut to commercial. Feel bad and buy Carbon Credits. “Did you know your car creates 10 trillion tonnes of CO₂ per day/hour/year”?

What are these numbers? Where do they get them? What are they talking about? 1 Tonne, or 1 ton? Is that metric? Is it imperial? How is that possible? How can air possibly weigh 1 tonne?

We’re going to give you the REAL numbers here. In the process, we’re going to learn about cars, combustion, and corruption. How much you burn in gasoline depends on a lot of different input.

• Engine Size
• Fuel Type
• consumption over time (RPM, tanks per week, average length and speed of a commute, etc.)
• Air Density (Sea Level, +/-)

But the reality is, the only way you put CO2 into the atmosphere is by burning gas. It doesn’t matter if you have a 4×4, a compact-car, or a motorbike. If you burn gas, you’re contributing to the CO2.

Let’s Begin. Click READ MORE.

Internal Combustion

If you don’t already know how an internal combustion engine works, I’ll do a brief review.

4 Stroke Engine

1. Intake stroke – Air and vaporised fuel are drawn into a cylinder
2. Compression stroke – Fuel vapor and air are compressed and ignited
3. Combustion stroke – Fuel combusts and piston is pushed downwards
4. Exhaust stroke – Exhaust is driven out

It doesn’t matter how you look at it, the process involves filling a chamber with the proper amount of air and vapourised gas, compressing it, and lighting it on fire.  Take a look at this SWEET VIDEO where someone took an ultra small and powerful camera and put it into a combustion chamber.  You can see everything.

This proper amount of fuel/air mixture depends on something called the Stoichiometric Ratio . It is the perfect chemical ratio of gas to air by weight. In the case of gasoline, it is 14.7:1. This is 14.7 air to 1 gas. So if we use up 1kg of gas, we use 14.7kg of air.

Wait. 14.7 kg of air? Yes. At sea level under normal temperatures, the density of air is about 1.25 kg/m3. Therefore, 14.7kg of air occupies a space of about 11.76 cubic metres. That’s about the volume of a small bedroom.

Wait. 1kg of gas (petrol)? At sea level and also at normal temperatures, the density of gasoline is 737.22 kg/1m³ (cubic metre). That’s pretty heavy. So 1 kg of gasoline = 737.22 cubic centimeters that’s about the volume of 2 pop cans.

Anyways, we’re talking weight. If my gas tank holds 55 litres, that’s a weight of about 40kg. 40 kg fuel plus (14.7kg * 40) 588kg of air= 628kg.

I will consume 628kg worth of air and gas every time I fill up. If all this goes into the atmosphere, which almost all of it does, that’s 628kg of stuff added to our atmosphere.

Emissions

Now, the question is, what is my CO2 emissions? how much of a car’s exhaust is CO2?

Fuel + Air => Hydrocarbons + Nitrogen Oxides + Carbon Dioxide + Carbon Monoxide + water (I guess)

So what’s the typical makeup of these components? How much ? To be honest, I DON’T KNOW. No politician or hippie I can find will post the true amount. I’ve looked around the net for about 20 minutes, but can’t find anything. Let’s assume that it is 100% of emissions. This is bullshit, but I can’t believe the information is just not out there. Someone please let me know if you find it.

UPDATE, Oct 03 2007 11AM EDT: A user has commented and left a web site for a resource in my comments. I have contacted the site owner and tried to verify their numbers and their source. According to that site, my estimation of 11kg of CO2 per litre of gas may be WAY too high.

However, when I read the site, it appears that they either goofed on the math, or are fudging the numbers worse than me. Does anyone think that the math below is wrong? If there are 3.7854118 litres per US gallon, how can 2.31kg per litre = 105kg per gallon?

From Google: 1 US gallon = 3.7854118 litres

From the website:

• Petrol: 1 litre = 2.31kg CO2

• Petrol: 1 gallon = 105kg CO2

For now, I will be keeping my numbers as is.

Because I have to work with the most honest numbers I can find, I have to assume that a LARGE amount is the Carbon Dioxide. But what’s a fair amount. Obviously, it’s the most important gas to the Global Warming case, so I’ll assume that it’s only a bit smaller than the stoichywhatever rate. Let’s say 12:1. 12:1/14.7:1=82%.

In this case, we’ll say that for every litre burned, 82% of the total post-combustion weight(the litre of gas and all associated air with burning it) is turned into Carbon Dioxide. I have no idea if this is correct, but it’s a good guess.

All things considered, burning 1 litre of gas perfectly without waste, will deliver 11.418 kg of Carbon Dioxide into the environment.

1 litre of gas produces 11.418kg of CO2

Considering the Car

So, right away we can come up with some pretty astounding figures.

Here’s a great site about gasoline consumption every year by country. Here’s an example of the world consumption of gasoline, and therefore, world production of CO2 emissions from gasoline.

Rank	Country	Thousands of metric tonnes	Millions of Barrels	Millions of Tonnes CO2 per Year	Millions of Litres per year
1	United States	379383	3167.848	5956.3131	514613.0056
2	California	44235.574	369.367	694.4985118	60003.22021
3	Japan	44086	368.118	692.1502	59800.33097
4	China People’s Republic of	37399	312.282	587.1643	50729.76859
5	Canada	29106	243.035	456.9642	39480.75201
6	Germany	27195	227.078	426.9615	36888.58143
7	Russia	25485	212.8	400.1145	34569.05673
8	Mexico	23058	192.534	362.0106	31276.95939
9	United Kingdom	20502	171.192	321.8814	27809.88036
10	Italy	16449	137.349	258.2493	22312.19989
11	Australia	13760	114.896	216.032	18664.71338
12	Iran Islamic Republic of	13599	113.552	213.5043	18446.32538
13	France	12932	107.982	203.0324	17541.57511
14	Brazil	11983	100.058	188.1331	16254.30672
15	Saudi Arabia	10962	91.533	172.1034	14869.37414
16	Indonesia	10125	84.544	158.9625	13734.02783
17	Venezuela	9567	79.884	150.2019	12977.1303
18	Spain	8206	68.52	128.8342	11131.00567
19	India	7570	63.209	118.849	10268.30525
20	Korea Republic of (South Korea)	7513	62.734	117.954	10190.98776
25	Thailand	5422	45.274	85.1254	7354.656683
78	Costa Rica	621	5.185	9.7497	842.3537072