A comprehensive quantification of global nitrous oxide sources and sinks.

Journal Article

Nitrous oxide (N2 O), like carbon dioxide, is a long-lived greenhouse gas that accumulates in the atmosphere. Over the past 150 years, increasing atmospheric N2 O concentrations have contributed to stratospheric ozone depletion1 and climate change2 , with the current rate of increase estimated at 2 per cent per decade. Existing national inventories do not provide a full picture of N2 O emissions, owing to their omission of natural sources and limitations in methodology for attributing anthropogenic sources. Here we present a global N2 O inventory that incorporates both natural and anthropogenic sources and accounts for the interaction between nitrogen additions and the biochemical processes that control N2 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 N2 O sources and sinks resulting from 21 natural and human sectors between 1980 and 2016. Global N2 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 N2 O emissions in emerging economies-particularly Brazil, China and India. Analysis of process-based model estimates reveals an emerging N2 O-climate feedback resulting from interactions between nitrogen additions and climate change. The recent growth in N2 O emissions exceeds some of the highest projected emission scenarios3,4 , underscoring the urgency to mitigate N2 O emissions.

Full Text

Duke Authors

Cited Authors

  • Tian, H; Xu, R; Canadell, JG; Thompson, RL; Winiwarter, W; Suntharalingam, P; Davidson, EA; Ciais, P; Jackson, RB; Janssens-Maenhout, G; Prather, MJ; Regnier, P; Pan, N; Pan, S; Peters, GP; Shi, H; Tubiello, FN; Zaehle, S; Zhou, F; Arneth, A; Battaglia, G; Berthet, S; Bopp, L; Bouwman, AF; Buitenhuis, ET; Chang, J; Chipperfield, MP; Dangal, SRS; Dlugokencky, E; Elkins, JW; Eyre, BD; Fu, B; Hall, B; Ito, A; Joos, F; Krummel, PB; Landolfi, A; Laruelle, GG; Lauerwald, R; Li, W; Lienert, S; Maavara, T; MacLeod, M; Millet, DB; Olin, S; Patra, PK; Prinn, RG; Raymond, PA; Ruiz, DJ; van der Werf, GR; Vuichard, N; Wang, J; Weiss, RF; Wells, KC; Wilson, C; Yang, J; Yao, Y

Published Date

  • October 7, 2020

Published In

Volume / Issue

  • 586 / 7828

Start / End Page

  • 248 - 256

PubMed ID

  • 33028999

Pubmed Central ID

  • 33028999

Electronic International Standard Serial Number (EISSN)

  • 1476-4687

International Standard Serial Number (ISSN)

  • 0028-0836

Digital Object Identifier (DOI)

  • 10.1038/s41586-020-2780-0

Language

  • eng