How can the Clean Development Mechanism contribute to better air quality?

Air pollutants and greenhouse gases are to a large extent emitted by the same sources, notably in the industry, transport and residential sectors. However, climate change mitigation is a global issue and is mostly driven by national and international policy. Local governments are in general more interested in improving urban air quality, which is posing serious health hazards across the globe. The Clean Development Mechanism (CDM) was designed to reduce greenhouse gas emissions, helping industrialised countries to achieve their targets under the Kyoto Protocol while contributing to sustainable development in developing countries. As of January 2009 over 4000 projects are in the pipeline.

The CDM could be used by local governments and the private sector to finance projects that contribute to both climate change mitigation and better air quality. However, CDM projects in particularly the transport sector face a number of barriers. We identify the most important issues for such projects, as well as the lessons learnt and some recommendations based on four case studies in Asian cities related to biofuels and bus rapid transit systems. The main conclusions is that successful implementation of CDM projects beneficial for urban air quality depends on the applicability of approved CDM methodologies, the strong cooperation between project developers and local authorities, and the availability of data.