Tree Branches

This guide describes the different types of tree branches used in the LEAP modeling software, explaining their functions, icons, and the types of data they handle across Demand, Transformation, and Resource analyses.

• Key Assumption branches represent independent time-series variables, such as GDP or population, which are defined globally and used as intermediate variables in modeling calculations, such as projecting energy demands via elasticities.
• Category branches organize data into hierarchical structures. In Demand branches, these structures are flexible with multiple levels; in Transformation branches, they indicate energy conversion modules (e.g., oil refining) and have restricted levels of disaggregation; in Resource branches, they organize primary resources and secondary fuels.
• Technology branches represent energy-consuming devices in Demand branches or conversion processes in Transformation branches. In Demand analysis, three specific types exist: Activity Level Technologies, Stock Technologies, and Transport Technologies.
• Fuel branches indicate output fuels in the Transformation tree, primary resources and secondary fuels in the Resource tree, and fuels for base year stock change or statistical differences in Stock Change and Statistical Differences branches.
• Environmental Loading branches, represented by a gray cloud, are used to specify emissions of pollutants wherever a fuel is combusted or under Non-Energy branches for sectors outside the main energy analysis.

APA

Stockholm Environment Institute (n.d.). Tree Branches. https://cdn.leap.sei.org/help24/Screen_Layout/Types_of_Tree_Branches.htm

Chicago

Stockholm Environment Institute. Tree Branches. n.d. https://cdn.leap.sei.org/help24/Screen_Layout/Types_of_Tree_Branches.htm.

Wikipedia

{{cite report |author=Stockholm Environment Institute |title=Tree Branches |url=https://cdn.leap.sei.org/help24/Screen_Layout/Types_of_Tree_Branches.htm |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{stockholmenvironmentinstitutendtree, author = {{Stockholm Environment Institute}}, title = {{Tree Branches}}, institution = {Stockholm Environment Institute}, url = {https://cdn.leap.sei.org/help24/Screen_Layout/Types_of_Tree_Branches.htm}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }