Your house may not be your biggest contributer to global
warming. Credit: Jim Gunshinan.

My focus in this blog had been on green homes, but there are other areas of our lives that account for our total carbon footprint–how much carbon we are responsible for adding to the atmosphere–a measure of our contribution to global warming. Our houses and apartments, but also our cars, air travel, and the food we eat all contribute.

Don Fugler, who does research for the Canada Housing and Mortgage Corporation, estimated the amount each area of our lives contributes to our carbon footprint. He used a hypothetical family of four (two adults, two kids) in Ottawa, with a medium-sized house (2,400 square feet), and two cars (Ford Explorer and Honda Fit) to do the calculations. Both parents work and travel about 20 miles roundtrip to work each weekday. The kids travel a few miles each day back and forth to school. Both parents make a total of five trips to Toronto and five trips to other places each year for business, and the family goes on a yearly ski trip to Whistler by air travel, and back and forth by car to visit relatives in Nova Scotia once a year.

For us Californians, replace Ottawa with Oakland, Whistler with Lake Tahoe, add a trip to Hawaii, and subtract most of the energy used for heating a house, and I think we come close to the Canadian example.

The folks who brought us the movie also gave us a nifty
carbon calculator. Use it to measure the size of your carbon
footprint (go to

Our hypothetical family, according to Don’s calculations, emits about 13 tons of CO2 from their house, about 14 tons because of air travel, about 10 tons from their cars, and about 5 tons from the food they eat (including growing, shipping, and waste disposal). Notice that the highest amount is from air travel!

The folks who brought us the movie An Inconvenient Truth also provide an online calculator so that you can more accurately calculate your contribution to global warming–the site also gives good information on how to reduce your carbon footprint. Don recommends that we conduct more and more of our business using the Internet instead of traveling far from our homes, live close to our jobs in dense urban areas with good public transportation, ride our bikes a lot, and all become vegetarians.

Jim Gunshinan is Managing Editor of Home Energy Magazine. He holds an M.S. in Bioengineering from Pennsylvania State University, State College, Pennsylvania, and a Master of Divinity (MDiv) degree from University of Notre Dame.


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Mapping Our Carbon Footprints 23 April,2013Jim Gunshinan

  • Fred Michel

    Don Fugler’s carbon footprint calculations for a family are interesting, unfortunately his airplane fuel calculation is wrong. I am surprized you did not check his calculations yourself. Here is a better estimate of the airline carbon footprint and how it is calculated –

    Price on ORBITZ for a RT plane ticket from Toronto to Vancouver during ski season = $574

    For four family members = $2296 total airfare (taxes not included)

    % Canadian Air costs attributed to fuel = 30%

    Family’s airfare attributable to fuel costs
    = 30% * $2296 = $689

    Price of jet fuel = 677 $/tonne

    Jet fuel used for family ski trip
    = $689/($677/tonne) = 1.02 tonne of jet fuel

    Amount of CO2 in one tonne of jet fuel
    (assume it is CH) = (44 g/mol )/(14 g/mol)
    = 3.67 g CO2 produced per g jet fuel burned (CH)

    Amount of CO2 produced by family for plane trip
    = 1.02 tonne fuel * 3.67 tonne CO2/tonne fuel
    = 3.20 tonne CO2 for the air travel,

    Fugler reports 13 tonnes of CO2 for the air travel.

    Fugler also reports that the family’s cars alone generate 9 tonnes of CO2. With my revised air travel CO2 numbers, the air travel generates about 1/3 as much CO2 as the auto travel and less then 1/3 as much as the house (11.5 tonnes) and less than the food they eat (4.5 tonnes)

    Still 3.2 tonnes for one trip is alot!


Jim Gunshinan

Jim Gunshinan is the editor of Home Energy, the magazine of sustainable home building and renovation.

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