Acid rain, considered hazardous until recently, helps in slowing the process of global warming, according to US scientists.
The sulphate present in the rain helps in retarding the process of global warming, an international research published in the Proceedings of the National Academy of Sciences has said.
In an experiment, Dr Vincent Gauci and his colleagues at an Open University in the United States chose several wetlands in the country, UK and Sweden and dosed them with various amounts of sulphate.
They decided to experiment in wetlands which provide fertile ground for the microbes that emit methane.
Methanogenic microbes, which produce methane in large quantities, are inhibited by a type of bacteria that thrives on sulphate present in acid rain, the report said.
Microbes produce about 32 per cent of the methane present in the environment, they said. "160m out of 500m tonnes of methane is produced by those microbes," they added.
The team, interested in guaging the emission level of methane, found that its emission was significantly suppressed due presence of sulphate.
All experimental sites displayed 30 to 40 per cent reduction in methane production as the team simulated low level of acid rain, the report said.
Methane exists in smaller quantities in the atmosphere as compared to carbon dioxide and accounts for about 22 per cent global warming which is caused due to human activities, it said.
