Costs of greenhouse gas emissions abatement under the clean development mechanism

This paper examines the costs of emissions abatement through various types of projects financed under the Clean Development Mechanism (CDM) of the Kyoto Protocol. Using project data, cost functions are estimated applying alternative functional forms. Results show that the average cost of abatement decreases with the volume of abatement, showing economies of scale and suggesting that reducing emissions through small projects is relatively expensive. Results also show significant variation in the costs of abatement by project type and location. Nevertheless, the observed distribution of project investments does not closely match the relative cost structure, either by location or project type. Renewable energy projects accounted for 62% of the projects even though they had the second highest cost. Most of the CDM projects are located in emerging economies, principally China, India, and Brazil, even though the fixed costs of establishing CDM projects in these countries are higher than in many other developing countries. Significantly, while much of the conceptual and applied numerical literature concerning greenhouse gas abatement policies relies on presumptions about the structure of abatement cost curves, these findings suggest that comparative advantage is only one of several factors driving CDM investments and that investors hold additional preferences about project location and project type. Finally, results indicate a general, though noncontinuous, downward trend in the costs of abatement for new CDM projects.