New Delhi: You wouldn't think cowdung could be the cause of global warming? Well, organic waste from dairy farms — rich in nitrogen compounds — is high on the radar of scientists across the world, studying impacts of excessive nitrogen on the environment. Says Senior Scientist, Biotechnology Institute, DR N Raghuram, "The climate change debate has predominantly focussed on carbon dioxide, but everybody in the field knew that there are many other components and gases which contribute to climate change." And reactive nitrogen is emerging as a serious trouble-maker. One nitrogen compound as compared to a carbon compound persists in the atmosphere for almost 100 years and is 296 times as potent a heat-trapping gas as carbon dioxide. The world-over, scientists are warming up to another reality, fertilisers used extensively in agriculture are top contributors to this excess. Says another senior scientist Dr Y P Abrol, "We have accumulated reactive nitrogen up to 200 million tonnes the world over, and this amount is going to go on increasing with the increase in population." So, where is all this reactive nitrogen coming from? Apart from fertilisers leaching into the soil, and running off into rivers, the transport sector releases nitrous oxides, and so does untreated sewage. Studies by Indian scientists indicate high levels of nitrates in our groundwater sources — a fact acknowledged by the Government — and this water or even food with excessive nitrates is no good for you and me. Says Dr Bijay Singh of the Punjab Agricultural University, "The nitrate once goes into our body along with the water, it becomes nitrite and combines with the haemoglobin to become met-haemoglobin, which can not transport oxygen from lungs to different body parts." Seventy eight per cent of the atmosphere is nitrogen gas and its compounds are the building blocks of life, but an excess of its compounds in our air, water and soil is a cause for alarm, say scientists. However, for India, in the absence of a dedicated nitrogen research facility, the solutions to this growing nitrogen problem aren't going to be easy.