Project Bundling of small scale projects for Joint implementation Among the Kyoto Protocol flexible mechanisms, the Joint Implementation (JI) is relevant in countries of Central and Eastern Europe while as the Clean Development Mechanism (CDM) relates to greenhouse gas reduction projects in Central and South America, Africa and Southeast Asia. Unfortunately, projects in these regions that would qualify for co-financing are often small (<10,000 tons of CO2-eq per year). This usually does not fit the requirements of carbon credit buyers who prefer contracting large projects (>50,000 tons of CO2e per year) in order to minimize the transaction costs. To use the emission reduction potential of small projects and at the same time to keep the transaction costs limited, the concept of flexible portfolio development has been established. This concept involves assembling a set of subprojects of the same or similar type into a bundle characterized by the following features: