Frequently Asked Questions

To learn, who BONSAI is, check the Who we are.

The Climate Footprint Analyser is:

• free
• global
• easy to use (does not require special skills)
• easily updated
• reliable and very precise

The database is based on the ISO standard for LCA, ISO 14044, which specifies that “The life cycle inventory is based on material balances between input and output. Allocation procedures should therefore approximate, as much as possible, such fundamental input/output relationships and characteristics.” For us, this means to follow the physical reality and avoiding normative choices. This way of modelling is known as “consequential Life Cycle Assessment” and is described in more detail at consequential-lca.org.

The database contains data for climate emissions from all over the world. You will find a list of countries currently included here. You will find current products and activities here.

We are aware that this is not easily readable at the moment, and we are working on better overviews of the products and their classifications. You are more than welcome to reach out, if you need more information.

A typical way to model the product system is to start with the foreground activity in which the decision to be supported is made (typically, the choice of one product instead of another). The studied change in the foreground activity implies a change in demand for intermediate product inputs, and thus to changes in the activities that supply these inputs and the further products upstream in the life cycle from purchaser to supplier.

In practice, the product system is modelled by tracing each required product input, physical or monetary, through the upstream chain of suppliers that will change their production capacity in response to an accumulated change in demand for the product. Similarly, product outputs are traced downstream in the chain, from suppliers to final disposal. When encountering co-producing activities that have more than one product output, the determining product of interest is isolated from the other co-products by subdivision following physical causalities in cases of combined production, and by expanding the product system to include the activities affected by the excess supply of by-products from joint production activities.

The tracing of intermediate product flows continues until all remaining physical flows either come from or go to the environment without further human transformation, and all economic revenue received in life cycle has been spent on primary factors (payments to employees and entrepreneurs, taxes, and rents), thus providing a clear delimitation of the activities included in the product system. This ensures that the resulting product systems are complete and maintain their physical and economic balances intact.

The above modelling follows a strict interpretation of the ISO 14040-series of standards on LCA and is often referred to as a consequential LCI model; see more at consequential-lca.org.

A consequential footprint is the result of a consequential Life Cycle Assessment. For a specific impact category, such as global warming (climate change) it communicates the impacts of the full life cycle of a product. In other words, it communicates the full consequences of continuing to produce, consume, and dispose of the product, compared to not producing, consuming, and disposing of the product.

The difference between two consequential footprints therefore expresses the impacts that would result from shifting between the two products. It is important to note that product comparisons are only valid when taking the 'monetary rebound' effect into account, namely that the choice of the cheaper option will leave the consumer with saved money that can then be used to purchase other products with their own environmental impacts. For a fair comparison of the environmental impacts from products with different prices, the environmental impacts of these alternative purchases would therefore have to be added to the cheaper product. A simple way to achieve this is to instead compare the products based on their impact per euro spent on the products. This also allows all products to be compared across all product categories, without need to consider functional or technical equivalence and market substitutability.

Constrained suppliers of a product are those that cannot change their production capacity in response to an accumulated change in demand for the product. The demand for their products will then instead be met by other suppliers that can change their supply, also known as unconstrained suppliers. When tracing the consequences of a change in demand, the consequential LCA model includes only unconstrained suppliers.

An often-encountered cause of constraints is joint production, where the production volume is determined by only one of the co-products, while the rest are dependent by-products. Dependent by-products from joint production activities always have a production volume that is constrained by the demand for the determining product of the joint production activity.

Substitution is the market reaction that occurs when the supply of a by-product cannot react to a change in demand. An increase in demand for the by-product will therefore be met (substituted) by an increase in the supply from the unconstrained suppliers to the market where the by-product is sold. Likewise, an excess supply of the by-product will reduce (substitute) the demand from the unconstrained suppliers. The modelling of substitutions in LCA is also known as “system expansion”, because the LCA model is expanded to include the activities affected by the excess supply of by-products from joint production activities.

Yes.

Well, in fact they are all products, but some are service products. For services, the names of the products are often the same as the names of the activity that produces the service.

By June 2025 we have included data from 48 countries. The Rest-of-World regions (RoW) cover the remaining countries. You will always be able to see the updated list of included countries.

GWP100 (IPCC AR5) for now, but this will be updated to IPCC AR6.

The BONSAI database had EXIOBASE as a starting point. This contains data from 2016. Even though we currently have more recent data for many products from all over the world, we need to make sure that the entire workflow is setup correctly to produce trustworthy results. When we have this in place, we will push more recent data (expectedly in August 2025).