Tribune News Service
New Delhi, October 7
“World’s first global assessment” of nitrous oxide, the primary greenhouse gases driving global warming, suggests it is beginning to exceed predicted levels across most Intergovernmental Panel on Climate Change (IPCC) emission scenarios.
It has risen 20 per cent from pre-industrial levels and its growth has accelerated over recent decades due to emissions from various human activities, say researchers of the new study that went live a short while back.
Agriculture is the main cause for this increase, contributing almost 70 per cent of emissions between 2007 and 2016, they say, adding that “emissions from synthetic fertilisers dominate releases in China, India and the US”.
Nitrous oxide has risen 20 per cent from pre-industrial levels and its growth has accelerated over recent decades due to emissions from various human activities, states the research by the Global Carbon Project and the International Nitrogen Initiative.
“The growing use of nitrogen fertilisers in the production of food worldwide is increasing concentrations of nitrous oxide in the atmosphere, a greenhouse gas 300 times more potent than carbon dioxide, which remains in the atmosphere longer than a human lifetime. The rising nitrous oxide emissions are not compatible with the Paris Agreement climate goals,” say researchers.
“Every year more than 100 million tonnes of nitrogen are spread on croplands around the world as synthetic fertiliser, and 100 million more fall onto pasturelands in manure from livestock. The biggest problem is that ever-increasing emissions driven primarily by our fertiliser use accumulate in the atmosphere faster than destruction can occur naturally,” they emphasised.
While emissions from synthetic fertilisers dominate releases in China, India and the US, emissions from the application of livestock manure as fertiliser dominates releases in Africa and South America.
The highest growth rates in emissions are found in emerging economies, particularly Brazil, China and India, where crop production and livestock numbers have increased, said the study.
In the coming decades, N2O emissions are expected to continue to increase as a result of the growing demand for food, feed, fibre and energy, and an increase in sources from waste generation and industrial processes. Opportunities for reducing emissions do exist.
There’s no simple alternative to nitrogen fertilisers without greenhouse gas emissions, unlike fossil fuel energy that can be replaced with renewable energies. Food production will always leak some nitrogen, but we can reduce the amount.
Lead author Professor Hanqin Tian, director of the International Center for Climate and Global Change Research at Auburn University’s School of Forestry and Wildlife Sciences says: “The dominant driver of the increase in atmospheric nitrous oxide comes from agriculture, and the growing demand for food and feed for animals will further increase global nitrous oxide emissions. There is a conflict between the way we are feeding people and stabilising the climate.”