Meeting Environmental and Energy Challenges: CNG Conversion of Motor Vehicles in Dhaka

Abstract

Petroleum fuels used in motor vehicles are a major source of local air pollutants and greenhouse gas emissions in Dhaka, the capital of Bangladesh, which already has poor air quality. Lack of their own oil resources also presents a major challenge to the policymakers regarding the sustainability of the transportation system. Under this circumstance, conversion of petroleum vehicles to run on compressed natural gas (CNG) offers multiple benefits to the country. This chapter quantifies the social benefits due to a government initiative that led to widespread conversion of petroleum motor vehicles to CNG vehicles. An impact-pathway model has been developed to relate the changes in emissions resulting from the policy to changes in ambient air quality and resulting number of avoided premature deaths. It is estimated that around 11,100 premature deaths can be avoided in Dhaka annually as a result of a complete switch from petroleum to CNG vehicles. This amounts to a saving of USD 1.33 billion a year, which is around 1.3 % of the GDP of the country. For climate benefits, impacts of black carbon (BC), organic carbon (OC), and SO₂ have been considered, in addition to the traditional greenhouse gases (GHG), CO₂ and methane. Although CNG conversion was detrimental from a climate change perspective using the changes in CO₂ and methane only (methane emissions increased), after considering all the global pollutants (especially the reduction in black carbon) the conversion strategy was beneficial. Considering the damage costs of CO₂, we find a benefit of around USD 25 million in a year, which is small compared to the health benefits. The strategy also helps the country save around USD 620 million worth of foreign currency a year. This indicates that policies focusing on individual country’s strengths can have large benefits in securing a sustainable energy future in the transportation sector.