Temporalis: an open source software for dynamic LCA

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An open source library for the Brightway2 LCA calculation framework that allows for a specific kind of dynamic life cycle assessments.

Source code is available on bitbucket, and documentation is available on read the docs.

Temporalis allows to perform dynamic LCA and take into account time in both inventory and impact assessment. It makes use of graph traversal and convolution to solve the inventory and makes it possible to use several types of impact assessment methods, both static and dynamic.

Temporalis has the following abilities:

  • Exchanges (technosphere inputs, and biosphere outputs) can be offset in time.
  • Individual exchanges can be split into multiple time steps, creating a temporal distribution for each exchange.
  • Inventory datasets can be given either relative or absolute dates and times.
  • Characterization factors can vary as a function of time.
  • Characterization factors can spread impact over time.

However, it has the following limitations:

  • Inventory datasets cannot change their inputs as a function of time (i.e. are time invariant). This limitation is necessary for the graph traversal to converge.
  • Exchanges must be linear, as in normal matrix-based LCA.

The article Temporalis, a generic method for dynamic Life Cycle Assessment (which is unfortunately still under review….) explains very nicely the methodology behind the software. This repo contains the jupyter notebooks with the analysis performed with some nice real usage examples of the software.

See also the demonstration notebooks and the examples.


The best way to install Temporalis is by using conda

The safest is to first install brightway2 and within the same conda environment run

pip install bw2temporalis

which will also install all its dependencies

Python version support

Python 3.5, and 3.6.


BSD 3-clause. See the file LICENSE.txt for details.

Additional Resources

Temporalis is a package extension of the advanced life cycle assessment framework Brightway2 which you should to use it. Here you can further info about it:



Any constructive contributions, bug reports, pull requests (both code and documentation), suggestions for improvements etc. is welcome. Just follow the contribution guidelines or take Contacts with the developers.

Code of conduct

Temporalis follows the Contributor Covenant. See the file CODE_OF_CONDUCT.md for details.