Climate-affecting methane and carbon monoxide from South Asia:Isotope constraints on emission sources

South Asia is home to 1.5 billion people and to 14 of the World’s 15 most polluted cities.

Its emissions of climate pollutants have severe effects on climate and the quality of the air people breathe, as well as on food and water security through cascade effects.This study aims to improve constraints on the South Asian emission sources of CH4 and CO – two key climate pollutants whose effective radiative forcing are together nearly of the same magnitude as CO2 globally, but whose sources and effects are much more uncertain.

Unfortunately, the global atmospheric observatory programs have very poor coverage of the South Asian region.The project will advance source-diagnostic multi-isotope fingerprinting at two strategically-located atmospheric observatories: The Bangladesh Climate Observatory, intercepting the integrated outflow of the highly polluted Indo-Gangetic Plain and The Maldives Climate Observatory in the Indian Ocean, intercepting the even broader outflow from the Indian subcontinent.Isotope fingerprinting of CH4 and CO will reveal the relative importance of key emission sources; to the benefit of improved understanding of their global mass balances, atmospheric chemistry and also serve to guide effective emission mitigation policies.