By Sankar Ray
Emerging economies pose threat to stratosphere due to an unprecedented increase in nitrous oxide (N2O) and leading among them are Brazil, India and China. Global anthropogenic (N2O) emission is due to agricultural production: 82 per cent. This is revealed in a paper, ‘Nature’: ‘A comprehensive quantification of global nitrous oxide sources and sinks’. It encapsulates in brief an extensive recorded data .spanning four decades, all over the world and findings thereof. It is an international collaboration project, essentially funded and monitored by Japan, in the project, Global Nitrous Oxide Budget 2020involves an international research team of 70 scientists and44 research organizations from around the world. These include two scientists from the National Institute of Environmental Studies (NIES) and Japan Agency of Marine Earth-Science and Technology (Jamstec) of Japan.
Among the authors are Hanqin Tian, Yuanzhi Yao, Hao Shiand Rongting Xu – all of Japanese origin – of the International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Shree R.C. Dangal of Woods Hole Research Center, Falmouth, MA and Eric A Davidson of Appalachian Laboratory, University of Maryland Center for Environmental Science, Frostburg ( all three in the USA), Angela Landolfi of GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany and Istituto di Scienze Marine, Consiglio Nazionale delle Ricerche (CNR), Rome, Italy, Wilfried Winiwarter of International Institute for Applied Systems Analysis, Laxenburg, Austria
Institute of Environmental Engineering, University of Zielona Góra, Zielona Góra, Poland and Parvadha Suntharalingam of School of Environmental Sciences, University of East Anglia, Norwich, UK. Prabir K.Patra, atmospheric physicist of Indian origin, a senior scientist, represents Jamstec.
An inventory, analysis and synthesis of the greenhouse gas across all sectors and regions is the construct of the comprehensive research, under the umbrella of Global Carbon Project (GCP). It is a venture to ‘develop a complete picture of the Greenhouse gases cycle by establishing complete, consistent scientific knowledge to support policy debate and actions to mitigate greenhouse gas emissions to the atmosphere, and will continue to be regularly updated with the most recent and reliable scientific findings. its importance, there is a lack of study that provides a full picture of global N2O emissions and the interactive effects between nitrogen (N) additions and the biochemical processes that control N2O’ .
In a press release on the work states, “The increase is primarily driven by human-induced emissions which have risen by 30 per cent over the period. Overall, agricultural activities dominated the growth in the emissions with the use of Nitrogen fertilizers in agriculture including livestock manure production. The highest growth rates in N2O emissions come from emerging economies, particularly Brazil, China, and India, where there has been large increases in crop production and livestock numbers”
On the findings that underscore the urgency to mitigate N2O emissions in the food production system, the researchers noted that. the emissions of this greenhouse ‘ are increasing as fast as or faster than the most pessimistic emission scenarios developed by the IPCC, which lead to global mean temperatures well in excess of 3 degree Celsius. The results provide the most comprehensive quantification of global N2O sources and sinks resulting from 21 natural and human sectors during 1980-2016.
The abstract of the paper states, Nitrous oxide, like carbon dioxide, is a long-lived greenhouse gas that accumulates in the atmosphere. Over the past 150 years, increasing atmospheric N2O concentrations have contributed to stratospheric ozone depletion and climate change, with the current rate of increase estimated at 2 per cent per decade. Existing national inventories do not provide a full picture of N2O emissions, owing to their omission of natural sources and limitations in methodology for attributing anthropogenic sources. . Here we present a global N2O inventory that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N2O emissions. We use bottom-up (inventory, statistical extrapolation of flux measurements, process-based land and ocean modelling) and top-down (atmospheric inversion) approaches to provide a comprehensive quantification of global N2O sources and sinks resulting from 21 natural and human sectors between 1980 and 2016.
Global N2O emissions were 17.0 (minimum–maximum estimates: 12.2–23.5) teragrams of nitrogen per year (bottom-up) and 16.9 (15.9–17.7) teragrams of nitrogen per year (top-down) between 2007 and 2016. Global human-induced emissions, which are dominated by nitrogen additions to croplands, increased by 30% over the past four decades to 7.3 (4.2–11.4) teragrams of nitrogen per year. This increase was mainly responsible for the growth in the atmospheric burden. Our findings point to growing N2O emissions in emerging economies —particularly Brazil, China and India. Analysis of process-based model estimates reveals an emerging N2O – climate feedback resulting from interactions between nitrogen additions and climate change. The recent growth in N2O emissions exceeds some of the highest projected emission scenarios 3, 4, underscoring the urgency to mitigate N2O emissions’.
The N2O emissions in India are mainly driven by the agriculture sectors, i.e., during the production of nitrogen-fertilisers, excessive application of nitrogen-fertiliser on cropland and management of manures. Technologies exist for cutting down release of N2O in the process of fertiliser production at the chemical plants and by optimally administering fertiliser application to the field without compromising yields. The same is true for China . but the additional factor is the production of adipic acid, a chemical that is used for nylon manufacturing. The N2O emissions in Brazil are due to farming of meat cows (manure management), and cropland expansion for soybean and corn production. (IPA Service)