When an equal amount of sulphate (deposited by acid rain) was added, it reduced methane emission by 43 per cent.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/acid-rain-checks-methane-emission
[2] http://admin.indiaenvironmentportal.org.in/category/author/savvy-soumya-mishra
[3] http://admin.indiaenvironmentportal.org.in/category/newspaper/deccan-herald-bangalore
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/acid-rain
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/agricultural-research
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/atmosphere-science
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/emissions-trading