Apply life cycle assessment (LCA) information
This guide explains how Climatiq integrates Life Cycle Assessment (LCA) approaches to accurately estimate emissions at each stage of a product, process, or service.
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.
For more in-depth understanding of LCA in general, these two links may be useful  (opens in a new tab)  (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.
For instance, when we consider the emissions from burning fuel in a car, CO2e is emitted when the fuel is combusted inside the vehicle. However, extraction of the fuel from the earth, its refinement, and transportation to the gas station also contribute to CO2e emissions.
Assessing Different Activities
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.
Considering Different Sources
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
Filtering LCA Activities
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 multiple emission factors match a specific query, such as when multiple sources specify an emission factor for the same activity, Climatiq will pick the newest one. However, if there are multiple emission factors from the same year valid for the query, the most conservative (the one with the highest co2e), will be picked instead.
To avoid this, 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.