pure_ghg_scores.py

import bw2data as bd
import bw2calc as bc

bd.projects.set_current("ghg-scores")

db = bd.Database("eg")
db.register()

a = db.new_node(code="a", name="a")
a.save()
b = db.new_node(code="b", name="b")
b.save()
ghg_flow = db.new_node(code="ghgs", name="GHG score", unit="kg CO2-eq.", type="emission")
ghg_flow.save()

a.new_edge(input=b, amount=1, type="technosphere").save()
b.new_edge(input=ghg_flow, amount=7, type="biosphere").save()

only_ghg_flows_lcia_method = bd.Method(("GHG scores", "direct"))
only_ghg_flows_lcia_method.write([(ghg_flow.key, 1)])

lca = bc.LCA({a: 1}, ("GHG scores", "direct"))
lca.lci()
lca.lcia()
lca.score
>>> 7.0