How much CO2 Did you Save?

Have you seen press releases from companies that talk about the number of metric tons of CO2 their company avoided by improving the efficiency of xyz systems?  Did you ever wonder how they calculate this?  Well, if you are keeping track of your energy use in your home (if not, you need to read our post on Energy Tools) you can use a very cool Greenhouse gas calculator from the EPA!

The Greenhouse Gas Equivalencies Calculator will help you find out how much CO2 (and other greenhouse gases) you've avoided by reducing one of the following:

• gallons of gasoline saved (if you keep track of mileage and fuel purchases year-over year)
• kilowatt-hours of electricity saved (if you keep track of electricity bills)
• therms of natural gas saved (if you keep track of gas bills)
• passenger vehicles affected this year (this is for individuals or companies that remove vehicles from their fleet)

If you provide the number of units saved for one of these categories above, the calculator will tell you the following:

1. How many metric tons of CO2 you avoided
2. Annual greenhouse gas emissions from x passenger vehicles.
3. CO2 emissions from x gallons of gasoline consumed.
4. CO2 emissions from x barrels of oil consumed.
5. CO2 emissions from x tanker trucks' worth of gasoline.
6. CO2 emissions from the electricity use of x homes for one year.
7. CO2 emissions from the energy use of x homes for one year
8. Carbon sequestered by x tree seedlings grown for 10 years.
9. Carbon sequestered annually by x acres of pine or fir forests.
10. Carbon sequestered annually by x acres of forest preserved from deforestation
11. CO2 emissions from burning x propane cylinders used for home barbeques.
12. CO2 emissions from burning x railcars' worth of coal.
13. Greenhouse gas emissions avoided by recycling x tons of waste instead of sending it to the landfill.
14. Annual CO2 emissions of x coal fired power plants.

EPA Greenhouse Calculator

So let's put this calculator to the test.  After looking at the spreadsheet of my electricity usage from 2007 to 2008, I can see that I reduced my annual electricity usage by 3,782 kWh.  I entered this into the calculator and here's what it gave me.

I avoided 2.7 metric tons of CO2 which is the equivalent of:

1. Annual greenhouse gas emissions from .5 passenger vehicles.
2. CO2 emissions from 308 gallons of gasoline consumed.
3. CO2 emissions from 6.3 barrels of oil consumed.
4. CO2 emissions from .04 tanker trucks' worth of gasoline.
5. CO2 emissions from the electricity use of .38 homes for one year.
6. CO2 emissions from the energy use of .25 homes for one year
7. Carbon sequestered by 69.6 tree seedlings grown for 10 years.
8. Carbon sequestered annually by .62 acres of pine or fir forests.
9. Carbon sequestered annually by .02 acres of forest preserved from deforestation
10. CO2 emissions from burning 113 propane cylinders used for home barbeques.
11. CO2 emissions from burning .01 railcars' worth of coal.
12. Greenhouse gas emissions avoided by recycling .94 tons of waste instead of sending it to the landfill.
13. Annual CO2 emissions of 0 coal fired power plants.

Several of these stats are very impressive while some are obviously more relevant to commercial buildings with more Greenhouse gas emissions to offset.  Here is my shortlist that I will commit to memory for the next cocktail party:

1. 2.7 Metric tons of CO2
2. 308 gallons of gasoline
3. 6.3 barrels of oil
4. 69.6 tree seedlings sequestering CO2 for 10 years
5. 113 propane cylinders used for a home BBQ

Imagine impressing your green friends with these statistics at the next gathering.  You'll be a regular Amory Lovins!  See what you can do once you start keeping track of and understanding your energy usage?  If you would like to try this for yourself and haven't started tracking your energy usage, go back to my Energy Tools post, get the value of the "therms of natural gas saved" from 2007 to 2008 and try this for yourself using this option in the calculator.    I don't know about you but this has encouraged me to start keeping track of gallons of gas purchased in my vehicles starting in the new year!

My next step is to take the open source formulas used in the EPA Greenhouse Gas calculator and incorporate them into my home energy tracking spreadsheet so it will calculate these values on the fly!