Joint Implementation (JI) refers to a system in which an advanced country of investment (a country which invests) reduces the amount of greenhouse gases emissions in a host advanced country of investment (a country where the activities are carried out); and the reduction of emissions achieved there (ERU: Emission Reduction Unit) is traded among these advanced countries.
共同実施(JIJointImplementation)とは、投資先進国（出資をする国）がホスト先進国（事業を実施する国）で温室効果ガス排出量を削減し、そこで得られた削減量(ERUEmissionReductionUnit)を取引する制度。