A high-level view of the proposed optimization model to determine optimal production pathways is shown in Figure . The model consists of a set of nodes N that represent basic products S, intermediate products I, final/output products P, and technologies T . The interdependency between technologies (production pathways) is represented via a set of links (edges) L. For convenience, we define the set of all products as M = S ∪ I ∪ P. Importantly, products in this modeling framework can also capture undesired byproducts, such as GHG emissions (in carbon equivalents). Each basic product i ∈ S has a supply amount s i ∈ R + , maximum supply capacity available s i ∈ R + , purchase cost α c i ∈ R + , and carbon footprint cost α CO 2 i ∈ R. The purchase cost is the supply/market cost of the input, while the carbon cost can be considered as the social cost of carbon or carbon price imposed for GHG emissions per unit of basic product supplied to the system. The carbon cost can be positive or negative; a negative value is interpreted as a carbon credit received (e.g., due to biological carbon sequestration from biomass); when the carbon cost is negative, this is seen as a value/service to society. A positive carbon cost, on the other hand, is interpreted as an impact/damage to society.