Carbon Footprint Estimator
A quick and easy version developed by Exploratorium Teacher Institute scientist
Bryce Johnson. Based on CoolClimate Carbon Calculator of CoolClimate Network, a
division of UC Berkeley's Renewable and Appropriate Energy Laboratory:
http://coolclimate.berkeley.edu/carboncalculator.
TRANSPORTATION – How You Get Around
A. Driving – Estimate how many miles you drive per year. The average American
drives 12,000 miles per year. Serious commuters might drive as much as 20,000 miles
per year, folks that use their cars sparingly might clock only 5,000 miles per year, while
the average 16 to 19 year old drives 7,500 miles per year.
(1) ________________ miles driven per year
Multiply (1) by (choose one)
0.6 kg of CO2 / mile if your car averages 20 mpg
0.4 kg of CO2 / mile if your car averages 30 mpg
0.3 kg of CO2 / mile if your car averages 40 mpg
Driving total (2) ________________ kg CO2 per year.
B. Flying – Estimate how many miles you fly each year.
(3) ________________ miles flown. Multiply this by 0.5 kg of CO2 / mile =
Flying total (4) ________________ kg CO2 per year.
C. Public Transportation –
(5) ________________ miles. Multiply this by 0.2 kg of CO2 / mile =
Public Transportation total (6) ________________ kg CO2 per year.
TRANSPORTATION TOTAL add (2), (4), and (6) =
(7) _____________ kg CO2 / year
HOME – How You Live
Circle the closest match to your living situation on the table below (values are in kg of
CO2 / year per home):
Number of bedrooms in living space
Number of
people in
living space,
including
yourself
1
2
3
4
1
2
3
4 or more
9000
6000
4000
3000
11,000
7000
5000
4000
12,000
8000
5000
4000
13,000
9000
6000
5000
The number you circled in the table above is (8) _____________ kg CO2 / year
How green is your home? If your home gets it energy from “clean” renewable energy
sources, multiply your answer from (8) by:
0.7 if your home gets 30 – 75% of its energy from renewables (somewhat rare)
0.8 if your home gets 10 – 30% of its energy from renewables
0.9 if your home gets 10% of its energy from renewables
1.0 if your home gets none of its energy from renewables
Note: California gets about 25% of its energy from renewables.
HOME TOTAL (9) _____________ kg CO2 / year
FOOD – What You Eat
Circle the most appropriate
Mostly vegan (no cheese or meat)
Vegetarian
Mixture of meat and vegetarian
Mostly Meat and Cheese eater
5,000 kg CO2 per year
6,000 kg CO2 per year
7,000 kg CO2 per year
10,000 kg CO2 per year
Enter the number for your diet choice here (10) _____________ kg CO2 / year
Where does your food come from? (circle the most appropriate)
I grow all my own food
500 kg CO2 per year
Mostly farmers markets and local sources 600 kg CO2 per year
Mixture of local and distant sources
750 kg CO2 per year
The super market / I don’t know
1,000 kg CO2 per year
Enter the number for your food source here (11) _____________ kg CO2 / year
FOOD TOTAL add (10) and (11):
(12) _____________ kg CO2 / year
GOOD AND SERVICES
How much do you consume? (circle the most appropriate)
I don’t buy much – I hate shopping 8,000 kg CO2 per year
Below average consumer
11,000 kg CO2 per year
Average American consumer
13,000 kg CO2 per year
Above average consumer
19,000 kg CO2 per year
GOODS AND SERVICES TOTAL (13) _____________ kg CO2 / year
CARBON FOOTPRINT TOTAL add (7), (9), (12) and (13) =
_____________ kg CO2 / year
Notes:
1. The average per capita carbon footprint for Americans is about 17 tons / year (1 kg =
2.2 lbs, so 17 tons = 34,000 lbs = 15,500 kg).
2. Carbon footprint in kg / year converted to number of charcoal briquettes (27g size) per
hour:
1
kg CO2 1 yr 1 day 12g C briquette
briquettes
×
×
×
×
= 0.001
yr 365 days 24hrs 44g CO2 0.027 kg C
hour
Example: A carbon footprint of 26,000 kg CO2 / year = 26 briquettes per hour, or about
one every 2 ½ minutes.