Each took anywhere between five and 20 minutes.
The answer is, of course, somewhere in between.
Most people won’t know exactly how many kilometres they drive or fly in a year, nor will they care to tot up their precise electricity usage by the kilowatt hour.
The Australian Greenhouse Calculator was, when it still worked, the most comprehensive piece of personal carbon accounting software.
Carbon Positive has a detailed list of where it takes the data from, while Carbon Neutral asks its users to look through the National Greenhouse Accounts Factors to figure out what assumptions it uses.
Much household-level data is no longer available, because major surveys like the Census or others run by the Australian Bureau of Statistics no longer look at the fine print of how households run.
“Most methodologies are bottom-up models.