Chicago Botanic Garden

CARBON Footprint CALCULATOR

Have you thought about your "carbon footprint"? Get out your utility bills and gas reciepts for a quick estimate. The calculator below will help you gain an approximate idea of how many tons of carbon dioxide some your activities generate and how many trees it would take to offset those emissions.

	Quantity	Total Tons of CO2 annually
Small car (40 mpg fuel economy)	miles per month
Average/medium car (21 mpg fuel economy)	miles per month
SUV/4 wheel drive (15 mpg fuel economy)	miles per month
Electricity usage	kilowatts/month
Natural/propane gas	cubic feet/month
Fuel oil heating	gallons per month
Air Travel	miles per month
Train Travel	miles per month
General waste - how many people in your household?	no. of people
How many people in your household have meat in their diet?	no. of people

*Total annual emissions*	tons
*Total monthly emissions*	tons
No. of trees to offset per year	trees
No. of trees to offset per month	trees
Carbon Dioxide Calculator v1.2 © Copyright Carbonify.com and Michael Bloch

Notes on CO2 emissions/offset calculator:

The calculator is not designed to be 100 percent accurate, as there are too many variables required in order to give a reliable emissions total. It is simply to give you an indication on how much carbon dioxide you generate and how many trees it would take to offset those emissions.

Bear in mind that just about all we do in modern life produces a carbon footprint, well over and above what occurs in the natural world. For instance, the computer you are viewing this on was produced using processes that create carbon emissions. Offsetting should be seen as a last resort; reduction in consumption is the first line of defense against global warming.

Unlike many calculators available on the web, I thought I'd let people know how these figures are arrived at in my script (corrections, suggestions and comments are welcomed). The calculations are based on the following:

Household electricity is based on a figure of 1.5 pounds of carbon emissions per kilowatt hour generated by a coal fired power station.³ Averages for USA based on Department of Energy, for Canada, the Ontario Ministry for Energy; for the UK, UK Environment Watch and for Australia, various state government environmental departments (averaged)
Natural gas emissions calculated on 0.12 pounds of carbon dioxide per cubic foot.⁵
Fuel oil based on 22.29 pounds CO2 emissions per gallon.⁵
Small car emissions calculated on .59 pounds emissions per passenger, per mile¹
Medium car emissions calculations based on 1.1 pounds of carbon dioxide emissions per mile¹
SUV/4 wheel drive carbon dioxide emissions based on 1.57 pounds per mile¹
Air travel emissions based on Boeing 747 at average USA capacity and calculated per person¹
Train travel calculations based on average occupancy of intercity train.¹
Tree offset calculation is based on a tree planted in the humid tropics absorbing on average 50 pounds (22 kg) of carbon dioxide annually over 40 years² - each tree will absorb 1 ton of CO2 over its lifetime; but as trees grow, they compete for resources and some may die or be destroyed - not all will achieve their full carbon sequestration potential. This calculator assumes that 5 trees should be planted to ensure that at least one lives to 40 years or that their combined sequestration equals 1 ton.
General waste is based on the USA average⁵ carbon dioxide emission equivalent of 1010 pounds per person per year. If your household recycles glass, paper, plastic and cans; only enter in half the number of people in your household for a more accurate figure.
Based on the average American diet generating the equivalent of 1.5 tons more carbon dioxide per year than a vegan diet.⁴

¹Source: Sightline Institute
² Source: Trees for the Future
³ Source: Various studies from around the world; averaged
⁴Source: University of Chicago study, May 2006
^5,6,7Source: USA Environmental Protection Agency