How do we know how any one factor contributes to climate change, for instance, how much vehicle emissions contribute as opposed to coal-fueled power stations?

We use carbon accounting to measure or estimate the emissions produced by different emissions sources or activities, such as driving a car or using a computer. Emissions can be direct or indirect. For example, driving a car produces direct emissions from the use of fuel by the car, while using a computer produces indirect emissions from the use of electricity generated at a coal-fuelled power station. Similarly, a piece of paper has associated indirect emissions from the production and transport of the product.

Some emissions are easier to calculate than others. For example, the Australian government provides emission factors to calculate emissions from the use of fuel in vehicles or natural gas at home, as well as electricity. An emission factor is a number that allows you to convert activity data (such as volume of fuel used, or weight of waste generated) into emissions. Emission factors that are relevant to a specific country or region might not be available for all sources of emissions.

There are several online calculators that may help you to calculate emissions from various sources. Some examples are the Carbon Footprint Calculator For Individuals And Households or the ClimateHero Carbon Calculator.

ClimateClever is another app that allows both households and businesses to calculate their carbon emissions, and then suggests ways to reduce these emissions. You can see how this kind of carbon accounting app works here: