Embedded carbon - the amount of carbon produced in the process of manufacturing goods or providing the infrastructure needed to use it.
Carbon cost involves far more than the amount of energy it takes to use a car or a dishwasher
The amount of energy it takes to produce the item itself has to be accounted for - and the amount of energy it takes to produce the infrastructure it uses. For example the carbon cost of a car journey needs to include the amount of fuel used but also has to factor in:-
- the energy used to manufacture the car, and its raw materials,
- the roads it runs on and the infrastructure that it takes to support using a vehicle
- the cost of producing the fuel
- the energy needed to recycle materials at the end of the vehicles life
Add all this to the equation and only about half of the emissions of an average car come from the exhaust pipe the rest come from the energy used to make the car, produce and distribute its fuel and provide the roads it depends on.
Almost everything has an embedded energy cost as well as a running cost - its one of the reasons it's generally better to try and make existing building more energy efficient rather than knocking them down and starting again! With a lot of renewable technologies the entire carbon cost comes from the process of manufacturing and installing plant - producing power creates no emissions at all - and its one of the reasons the effectiveness of renewable technology is measured by calculating the "Energy Returned on Energy Invested" or "EROEI".