# How much CO2 am I saving?

**URL:** <https://boards.straightdope.com/t/how-much-co2-am-i-saving/423702>\
**Category:** Factual Questions\
**Created:** [October 23, 2007, 3:05pm UTC](https://boards.straightdope.com/t/how-much-co2-am-i-saving/423702 "2007-10-23T15:05:23Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\
**Post date:** [October 23, 2007, 3:05pm UTC](https://boards.straightdope.com/t/how-much-co2-am-i-saving/423702/1 "2007-10-23T15:05:23Z")

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I telecommute one day per week.

Round trip is 205.3 miles.  
Miles per gallon is 20.  
Vehicle is a 1999 Jeep Cherokee with a 4.0 litre engine.

I went to a calculator I found online and entered 205.3 miles as my annual mileage. It said that puts 209 pounds of CO2 into the atmosphere every year. So I gave it 205.3 miles per week and devided the result by 52. Still 209 pounds.

How much CO2 am I _really_ not putting into the atmosphere each day I don’t drive?

How does the calculator get 209 pounds of CO2 from 70 pounds of gas?

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**Author:** ![borschevsky](https://avatars.discourse-cdn.com/v4/letter/b/97f17d/32.png) [@borschevsky](https://boards.straightdope.com/u/borschevsky)\
**Post date:** [October 23, 2007, 3:13pm UTC](https://boards.straightdope.com/t/how-much-co2-am-i-saving/423702/2 "2007-10-23T15:13:32Z")

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[QUOTE=Johnny L.A.]  
How does the calculator get 209 pounds of CO2 from 70 pounds of gas?  
[/QUOTE]  
It’s because the C comes from the gas and the O2 comes from the air, though I haven’t checked that their calculation is correct.

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**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\
**Post date:** [October 23, 2007, 3:25pm UTC](https://boards.straightdope.com/t/how-much-co2-am-i-saving/423702/3 "2007-10-23T15:25:33Z")

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[QUOTE=borschevsky]  
It’s because the C comes from the gas and the O2 comes from the air…  
[/QUOTE]

:smack:

It’s still a surprising amount if the calculator is correct.

EDIT: On the other hand, the fuel/air ratio is like 15:1, so that’s a lot of O2.

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**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\
**Post date:** [October 23, 2007, 3:29pm UTC](https://boards.straightdope.com/t/how-much-co2-am-i-saving/423702/4 "2007-10-23T15:29:18Z")

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Well, if gasoline weighs around 7 pounds per gallon and you get around 3\*7 miles to the gallon and you produce 3 pounds of CO2 for each pound of gasoline, you ought to emit about a pound of CO2 per mile, right?

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**Author:** ![Shoeless](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shoeless/32/7099_2.png) [@Shoeless](https://boards.straightdope.com/u/Shoeless)\
**Post date:** [October 23, 2007, 4:09pm UTC](https://boards.straightdope.com/t/how-much-co2-am-i-saving/423702/5 "2007-10-23T16:09:48Z")

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[Here’s a thread](http://boards.straightdope.com/sdmb/showthread.php?t=369637) where I asked a similar question. I think this was after I had seen “An Inconvenient Truth” and then was looking at an emissions calculator on Terrapass or some such site. I was surprised at the amount too.