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A comprehensive quantification of global nitrous oxide sources and sinks.
- Source :
-
Nature [Nature] 2020 Oct; Vol. 586 (7828), pp. 248-256. Date of Electronic Publication: 2020 Oct 07. - Publication Year :
- 2020
-
Abstract
- Nitrous oxide (N <subscript>2</subscript> O), like carbon dioxide, is a long-lived greenhouse gas that accumulates in the atmosphere. Over the past 150 years, increasing atmospheric N <subscript>2</subscript> O concentrations have contributed to stratospheric ozone depletion <superscript>1</superscript> and climate change <superscript>2</superscript> , with the current rate of increase estimated at 2 per cent per decade. Existing national inventories do not provide a full picture of N <subscript>2</subscript> O emissions, owing to their omission of natural sources and limitations in methodology for attributing anthropogenic sources. Here we present a global N <subscript>2</subscript> O inventory that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N <subscript>2</subscript> O 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 N <subscript>2</subscript> O sources and sinks resulting from 21 natural and human sectors between 1980 and 2016. Global N <subscript>2</subscript> O 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 N <subscript>2</subscript> O emissions in emerging economies-particularly Brazil, China and India. Analysis of process-based model estimates reveals an emerging N <subscript>2</subscript> O-climate feedback resulting from interactions between nitrogen additions and climate change. The recent growth in N <subscript>2</subscript> O emissions exceeds some of the highest projected emission scenarios <superscript>3,4</superscript> , underscoring the urgency to mitigate N <subscript>2</subscript> O emissions.
Details
- Language :
- English
- ISSN :
- 1476-4687
- Volume :
- 586
- Issue :
- 7828
- Database :
- MEDLINE
- Journal :
- Nature
- Publication Type :
- Academic Journal
- Accession number :
- 33028999
- Full Text :
- https://doi.org/10.1038/s41586-020-2780-0