Apply life cycle assessment (LCA) information

Life cycle assessment (LCA) is a methodology for assessing the environmental impacts associated with all stages of a product, process or service. Before making emission factors available in the API, Climatiq assesses the LCA approach taken by each source in developing the factors they publish. Each emission factor is then labelled with an appropriate label to help understand how the emission factor was reached, and to what activity - or aspect of an activity - the factor applies.

If you want to learn more about LCA in general, these two links may be useful [1] (opens in a new tab) [2] (opens in a new tab).

Applying LCA information

When calculating the emissions from an activity, you can split the activity into several sub-activities. Depending on your needs, you might want to include all or only some of these activities.

Let us use the example of burning fuel in a car. CO2e is emitted when the fuel is combusted inside the vehicle, but extracting the fuel from the earth, refining it and shipping it to the gas station also emits CO2e.

Depending on what you want to assess, you might need to only include the CO2e from the combustion of the fuel, or you might be interested in the more complete number that also includes fuel extraction and transportation.

Sources handle LCA activities differently. One source might list emission factors for the two aforementioned activities separately. The combustion of the fuel might have its own emission factor with the LCA activity listed as fuel_combustion, with another "upstream" emission factor for the extraction, refinement and transportation of the fuel listed as well_to_tank. Both of these factors will tend to use the same unit of activity (e.g. passenger-kilometres for example), so that you could assess the impact of a given activity in a straightforward way.

Another source might not perform this separation, and would instead only provide one emission factor that encompasses both activities. This activity might have a life-cycle activity called fuel_upstream-fuel_combustion that covers both the upstream (well-to-tank) activity and the combustion of the fuel. You might have noticed that there is a discrepancy in the naming conventions here; this is something that comes with slightly different approaches being used by the sources issuing these factors, which we adhere to in order to avoid erroneous calculations.

Not all sources specify what sort of LCA activities they consider at all. These LCA activities are listed as unknown

If you do not explicitly filter on an LCA activity, Climatiq will consider all LCA activities as equally good matches, and will default to the highest factor that matches the query made.

If this is not desired, you should explicitly filter on the source_lca_activity field, and refer to the different sources to see what they consider to be part of each lca_activity.