Personal greenhouse impact calculator
This page was created on 2005/01/02
(January 2nd 2005); modified 2015/08/03
For comments please email firstname.lastname@example.org
I hope that you will find this page useful. Any suggestions on
how the page might be improved would be appreciated; email
address is above. I believe the conversion factors that I have
used are approximately correct; in many cases it is imposible to
have exact figures (eg. brown coal has a highly variable composition
and power stations that burn brown coal vary in their efficiencies).
Obviously I'd like to be informed of any errors that I might have made.
I decided to calculate my
impact, and to record the data and equations I used to do it.
There are a number of components to consider in calculating
one's greenhouse impact, such things as:
- Your household greenhouse gas impact;
- The use of your car(s);
- Travel on public transport:
- Indirect greenhouse gas production: from the manufacturing of the things
you buy, the production of the food you eat, and their transport to the
shop where you buy them;
- Greenhouse abating activities, such as growing trees;
Personal greenhouse impact calculation
Please note that this page deals only with the
greenhouse gas Carbon dioxide (CO2)
CO2 is the most important man-made greenhouse gas because
of the very long time that it remains in the atmosphere. There are
other significant man-made greenhouse gasses.
All these calculators depend on some asumptions, you should
take the results as being a guide rather than being exact.
Use this calculator to find
out how much carbon dioxide is released into the atmosphere
following a known amount of electricity consumption. You could
get your consumption from your electricity bills.
Notes: The conversion factor depends on how your power is
generated; natural gas releases the least carbon dioxide per unit
of electricity generated, oil is
next best, then black coal, with brown coal worst of all.
The transmission loss is the percentage of the electricity generated
that is lost before it gets to your home; in general, the further
you are from the power station the greater the transmission loss.
For example the Queensland (Australia) Government in its Net page
Energy Losses in the Transmission and Distribution Systems,
states that the annual, weighted average transmission and distribution
loss factor in Queensland is about 10%, and that the
loss factor would be higher when demand is higher, lower when demand
More on boiling water:
The minimum amount of water that a typical
cordless electric jug can heat is 480mL. Every time one of these is used to
heat a mug of water (about 280mL) for tea or coffee, starting from 25 degrees
Celcius, I calculate that 0.018 kWhs is wasted in boiling that extra 200mL.
Assuming that this electricity is from a brown coal fired power station 23g
of unnecessary CO2 is released to the atmosphere. If this is done twice a day
for a year we have 17kg of CO2. Who is carefull to fill a jug exactly to
the minimum mark? If the jug is filled 20% above the minimum
(576mL rather than 480mL), then the figure
becomes 24kg of unnecessary CO2 per year - just from making two mugs of
tea each day!
If you know (or can estimate)
how much vehicle fuel you have used you can use this calculator
to convert that into released atomospheric carbon dioxide.
Alternatively you can use another calculator to work out your CO2 based on
Note: The constant 3.6667 is for converting kg of carbon to kg
of CO2. One kg of carbon combines with 2.6667kg of oxygen
to form 3.6667kg of CO2.
Use this calculator to compare driving your car with using public transport.
This calculator works out each passenger's share of the total CO2 from each
The figures from this calculator depend on assumptions made
about the number of passengers in the particular mode of
transport (that is, the 'load factor'). Obviously a 40
passenger bus with only half a dozen people in it is not
an efficient form of transport.
Kg CO2 per passenger Km for various vehicles and
numbers of passengers
This graph shows how the amount of CO2 released from a car,
when figured on a per passenger basis, varies
depending on the size of the vehicle and the number of passengers.
The tall purple bar in the back row indicates that in a big 4WD (SUV) with
only one passenger about 0.4kg (400 grams) of CO2 is released
every kilometre travelled.
The short blue bar in the front row shows that at the other end of the
scale, in a mini car with four passengers, only 0.045kg (45 grams) of
CO2 is released every passenger-kilometre travelled.
Use this calculator to get an approximate figure of how much
CO2 will be taken from the atmosphere by a stand
of growing trees.
There is an example of the use of this calculator on
A figure of 50% (0.5) for the carbon content of oven-dry
wood (and other tree matter, eg. leaves) has been used in the
calculation above. I have also
used 50% for the water content of the trees. (50% of 50%
= 25% carbon content of the standing trees, therefore the
factor of 0.25 in the equation.) Of course these figures are
very much approximations. The figure 3.6667 reflects the fact that when a
tree builds 1kg of carbon into itself, 3.6667kg of carbon dioxide is
removed from the atmosphere.
On my own property at Clare in South Australia, with an annual rainfall of
about 600mm, I have estimated that eucalypt trees gain something like 200%
increase in mass annually from about year 1 to year 5, then perhaps 100%
annually to year 10. This supposes that they are not competing with their
Some figures on greenhouse gas emissions from vehicles are given on
this EPA Victoria page. I have reproduced these below:
In the first table I have added the third column; in that column 3
passengers are assumed, including the driver.
|Cars||kg CO2/vehicle km
||kg CO2/person km
|V8 car or large 4WD (SUV)||0.41
|Large 6 cylinder car||0.35
|Medium 4 cylinder car||0.30
|Small 4 cylinder car||0.23
In this table I have also added the third column, in that
column I have assumed two-thirds of a full passenger load.
|Public transport||kg CO2/vehicle km
||kg CO2/person km
|40-50 seat bus (diesel)||1.30
|17-25 seat bus (diesel)||0.50
| 9-11 seat bus (diesel)||0.32
| 9-11 seat bus (petrol)||0.40
|Tram (100 passengers)||1.80
|Train (6 carriages, 600 passengers)||11.10
|Train (3 carriages, 300 passengers)||5.40
An Australian greenhouse
calculator, from the EPA of Victoria, Australia.
This claims to be able to calculate the greenhouse impact of your home.
It seemed to me to be unnecessarily complicated. I believe it to be
simpler to use electrical (and gas and heating oil, if applicable)
A useful 'intercity transport emissions calculator' is at
Climate Change Solutions.
Relating to the carbon content of wood, "Analysis of Wood
Product Accounting Options for the National Carbon Accounting
System" report of the
Australian Greenhouse Office.
Some of the figures used here for specific gravity were obtained
List of common conversion factors (University of
California-Berkeley Astronomy Department).
CO2 from air travel,
Air Travel Emissions (Rocky Mountain Institute).
Coal-fired power stations burning:
- black coal, about 1.2MWh electricity is
produced from 1 tonne of coal;
- brown coal, about 0.8MWh electricity is
produced from 1 tonne of coal;
Calculation of kg of CO2 released from burning a
litre of liquid fuel:|
- Specific gravity of LPG is 0.52;
- Formula of LPG is approximately C4H10;
Molecular weight = 58;
Atomic weight of 4 carbon atoms = 48;
Proportion of carbon in molecule = 48/58 = 0.83;
Petrol (gas in USA)
- Specific gravity of petrol is 0.74;
- Formula of petrol is approximately C8H18;
Molecular weight = 114;
Atomic weight of 8 carbon atoms = 96;
Proportion of carbon in molecule = 96/114 = 0.84;
- Specific gravity of diesel is 0.85;
- Formula of diesel is approximately C16H34;
Molecular weight = 226;
Atomic weight of 16 carbon atoms = 192;
Proportion of carbon in molecule = 192/226 = 0.85;
Conversion of carbon to CO2
44/12 = 3.67; ie. 1kg of carbon combined with oxygen
becomes 3.67kg of CO2.
- Molecular weight of CO2 = 44;
- Atomic weight of carbon = 12;