Using source_lca_activity with Climatiq

This guide explains how Climatiq integrates Lifecycle Assessment (LCA) from various sources into emission factor data and how to choose an LCA activity for a number of example use cases.

Each emission factor within the Climatiq database represents an activity or group of activities that gives rise to greenhouse gas emissions. Before adding emission factors to the database and making them available through the API, Climatiq assesses the LCA (Lifecycle Assessment) approach taken by the source. Each emission factor is then labelled to reflect the activities included.

The source_lca_activity field within the Climatiq database indicates which of the life cycle stages, or activities within each stage, are covered by the emission factor.

For a general introduction to the lifecycle assessment methodology, see A Quick Guide to Lifecycle Assessments.

Corporate Reporting

For corporate reporting you need to consider the LCA stages in terms of their use for Corporate Reporting in the Greenhouse Gas Protocol (GHGP).

In GHGP the terms “upstream” and “downstream” relate to a company, not a good or service. They are defined by who pays for and / or performs the good or service. In general goods and services paid for by the reporting company are upstream and those paid for by others are downstream. There are 15 scope 3 categories and the first eight (e.g. purchased goods and services and business travel) are upstream from the company and the last 7 (e.g. use of sold products, end of life) are downstream. See A Quick Guide to Lifecycle Assessments article for an explanation of how this differs from a product-focused LCA approach.

Choosing a source_lca_activity

The first step is to choose the appropriate emission factor for the good or service, represented by the activity_id. See the article here for an explanation of activity_id.

When you have picked your activity_id (and year, region, and source if applicable) then you can use the search endpoint to find the associated source_lca_activity entries.

The next sections explain how Climatiq handles the various different LCA activity information provided by emission factors providers / sources and how the API chooses between source_lca_activity when none is specified. After that there are some common use case examples.

The table at the end of this article lists all the main source_lca_activity entries and what they mean.

LCA under Different Sources

Sources (e.g. UK Government, EPA, ADEME) handle LCA activities differently. Taking a fuel as an example, one source might provide separate emission factors for the activities associated with the fuel and another might combine all activities into one emission factor.

In the first case, the combustion of the fuel might have LCA activity fuel_combustion, with another "upstream" emission factor for the extraction, refinement and transportation of the fuel with LCA activity well_to_tank.

In the second case a source may provide one emission factor that includes both activities. This activity might have a life-cycle activity called fuel_upstream-fuel_combustion that covers both well-to-tank and combustion.

At Climatiq we try to use the same terms as the sources so there may be some differences in source_lca_activity labels for emissions factors for similar activities from different sources.

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

Filtering LCA Activities and defaults

You can filter on LCA activity in the search endpoint and estimate endpoint. If you don’t explicitly apply filters, Climatiq will return the emission factor with the highest value that matches the query made.

If the query returns emission factors for more than one year then the API will pick the newest one. If there are multiple emission factors from the same year the API will pick the one with the highest value.

To avoid the API from using the newest / highest emission factor you need to provide an explicit filter on the source_lca_activity field. You may need to refer to the table below / to the source to see what each source_lca_activity represents.

Example reporting use cases

Fuel combustion (including travel and transport)

Use case: You want to report scope 1 emissions from fuel combustion in assets you own or operate, or scope 3 emissions from assets owned or operated by a third party (for scope 3, you may also need to include upstream emissions as well.)

Emissions from the fuel combustion (also known as tailpipe or tank-to-wheel) are, for the majority of emission factors, labelled source_lca_activity: fuel_combustion or source_lca_activity: tank_to_wheel.

Upstream emissions from the production of fuel

Use case: You want to report scope 3.3 emissions from the production of fuels burned in assets you own or operate, or complete scope 3 emissions from assets owned or operated by a third party

Emissions from the production of fuels (also known as well-to-tank) are, for the majority of emission factors, labelled source_lca_activity: well_to_tank.

Electricity

Use case: You want to report scope 2 emissions from the use of electricity in assets you own or operate

Scope 2 emissions arise from fuel combustion in power plants. Use source_lca_activity: electricity_generation.

Use case: You want to report scope 3 emissions from the use of electricity in assets you own or operate

Scope 3 emissions arise from the production of fuels used in electricity generation and emissions associated with the generation of electricity lost in transmission & distribution.

Some sources (e.g. BEIS) provide three emission factors to cover these. Others use just one or two. Note that for electricity you will (unless you use the Energy Feature) use two activity_ids. The relevant combinations of activity_id and source_lca_activity are as follows for the most popular sources.

See the Energy feature and the guide for Fuel and Energy Related Activities for more details.

Emissions from the purchase (production and transportation of) goods and services

Use case: You want to report scope 3.1 or 3.2 emissions from the purchase of goods and services or capital goods.

Emissions arise from upstream activities in the production of goods and services including primary production (extraction of raw materials, growing crops), refining / processing, manufacturing, packaging and transportation between stages.

For all spend-based emission factors (EXIOBASE, EPA, BEIS) and most other emission factors there is only one source_lca_activity for each activity_id.

The exceptions are for sources such as CBAM, ecoinvent and for food products. In these cases you will need to read the description (available in Explorer) of the emission factor and pick the one most suited to your case.

List of source_lca_activity

The table below sets out the most common source_lca_activity field values used in the Climatiq database. It is ordered by the most-used emission factors first (fuel combustion and electricity generation) then in approximate order of LCA stage. Where the definition is specific to a source, the source name is given before the description (e.g. CCF, IPCC, EPA).

The majority (97%) of emission factors relate to the upstream and / or use phases. This is because most emission factors relate to the production of a good or service (upstream) or the combustion of a fuel (use).

The remaining (3%) of emission factors relate to the downstream phase - activities associated with their processing or from their disposal or other end-of-life treatment.

Spend-based emission factors

Spend-based emission factors are produced in a very different way to all other emission factors. They use emissions data from each industry and how much is spent between industries to estimate total emissions from expenditure on a particular industry. As such they include a share of emissions from every industry involved directly or indirectly in the production of a good or service. They are therefore much more comprehensive in their coverage than LCA-based emission factors that will only include significant sources of emissions. The LCA activity may be listed as unknown but it is typically functionally equivalent to cradle_to_gate.