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Harris E, Yu L, Wang YP, Mohn J, Henne S, Bai E, Barthel M, Bauters M, Boeckx P, Dorich C, Farrell M, Krummel PB, Loh ZM, Reichstein M, Six J, Steinbacher M, Wells NS, Bahn M, Rayner P. Warming and redistribution of nitrogen inputs drive an increase in terrestrial nitrous oxide emission factor. Nat Commun 2022; 13:4310. [PMID: 35879348 PMCID: PMC9314393 DOI: 10.1038/s41467-022-32001-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/11/2022] [Indexed: 11/17/2022] Open
Abstract
Anthropogenic nitrogen inputs cause major negative environmental impacts, including emissions of the important greenhouse gas N2O. Despite their importance, shifts in terrestrial N loss pathways driven by global change are highly uncertain. Here we present a coupled soil-atmosphere isotope model (IsoTONE) to quantify terrestrial N losses and N2O emission factors from 1850-2020. We find that N inputs from atmospheric deposition caused 51% of anthropogenic N2O emissions from soils in 2020. The mean effective global emission factor for N2O was 4.3 ± 0.3% in 2020 (weighted by N inputs), much higher than the surface area-weighted mean (1.1 ± 0.1%). Climate change and spatial redistribution of fertilisation N inputs have driven an increase in global emission factor over the past century, which accounts for 18% of the anthropogenic soil flux in 2020. Predicted increases in fertilisation in emerging economies will accelerate N2O-driven climate warming in coming decades, unless targeted mitigation measures are introduced.
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Affiliation(s)
- E Harris
- Swiss Data Science Centre, ETH Zurich, 8092, Zurich, Switzerland.
- Functional Ecology Research Group, Institute of Ecology, University of Innsbruck, 6020, Innsbruck, Austria.
| | - L Yu
- Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School (SIGS), Tsinghua University, Shenzhen, 518055, China
- Laboratory for Air Pollution & Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Duebendorf, Switzerland
| | - Y-P Wang
- Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, VIC, 3195, Australia
| | - J Mohn
- Laboratory for Air Pollution & Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Duebendorf, Switzerland
| | - S Henne
- Laboratory for Air Pollution & Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Duebendorf, Switzerland
| | - E Bai
- Key Laboratory of Geographical Processes and Ecological Security of Changbai Mountains, Ministry of Education, School of Geographical Sciences, Northeast Normal University, Changchun, 130024, China
| | - M Barthel
- Department of Environmental Systems Science, ETH Zurich, 8092, Zurich, Switzerland
| | - M Bauters
- Isotope Bioscience Laboratory - ISOFYS, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - P Boeckx
- Isotope Bioscience Laboratory - ISOFYS, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - C Dorich
- Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, 80523, CO, USA
| | - M Farrell
- CSIRO Agriculture and Food, Locked bag 2, Glen Osmond, SA, 5064, Australia
| | - P B Krummel
- Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, VIC, 3195, Australia
| | - Z M Loh
- Climate Science Centre, CSIRO Oceans and Atmosphere, Aspendale, VIC, 3195, Australia
| | - M Reichstein
- Department of Biogeochemical Integration, Max Planck Institute for Biogeochemistry, Jena, Germany
| | - J Six
- Department of Environmental Systems Science, ETH Zurich, 8092, Zurich, Switzerland
| | - M Steinbacher
- Laboratory for Air Pollution & Environmental Technology, Empa, Swiss Federal Laboratories for Materials Science and Technology, 8600, Duebendorf, Switzerland
| | - N S Wells
- Centre for Coastal Biogeochemistry, Southern Cross University, Lismore, NSW, 2480, Australia
- Department of Soil and Physical Sciences, Agriculture and Life Sciences, Lincoln University, Lincoln, 7647, New Zealand
| | - M Bahn
- Functional Ecology Research Group, Institute of Ecology, University of Innsbruck, 6020, Innsbruck, Austria
| | - P Rayner
- School of Geography, Earth and Atmospheric Sciences, University of Melbourne, Parkville, VIC, 3052, Australia
- Melbourne Climate Futures Climate and Energy College, University of Melbourne, Parkville, VIC, 3052, Australia
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Denmead OT, Chen D, Griffith DWT, Loh ZM, Bai M, Naylor T. Emissions of the indirect greenhouse gases NH3 and NOx from Australian beef cattle feedlots. ACTA ACUST UNITED AC 2008. [DOI: 10.1071/ea07276] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Emissions of indirect greenhouse gases, notably the nitrogen gases ammonia (NH3) and the odd oxides of nitrogen (NOx), play important roles in the greenhouse story. Feedlots are intense, but poorly quantified, sources of atmospheric NH3 and although production of NOx is to be expected in feedlots, rates of NOx emission are virtually unknown. In the atmosphere, these gases are involved in several transformations, but eventually return to the earth in gaseous or liquid form and can then undergo further transformations involving the formation and emission of the direct greenhouse gas nitrous oxide (N2O). The IPCC Phase II guidelines estimate that indirect N2O emissions due to atmospheric deposition of N compounds formed from NH3 and NOx could be ~14% of the direct emissions from agricultural soils or from animal production systems. IPCC recommends that these indirect emissions be accounted for in making inventory estimates of N2O emission. This paper is a preliminary report of emissions of NH3 and NOx from two Australian feedlots determined with micrometeorological techniques. Emissions of nitrogen gases from both feedlots were dominated by emissions of NH3. The average NH3 emission rate over both feedlots in winter was 46 g N/animal.day, while that of NOx was less than 1% of that rate at 0.36 g N/animal.day. It was apparent that NH3 release was governed by the wetness of the surface. Rates of emission from the feedlot with the wetter surface were almost three times those from the other. The IPCC default emission factor for the combined emission of NH3 and NOx from livestock is 0.2 kg N/kg N excreted, but in our work, the emission factor was 0.59 kg N/kg N excreted. Potential emissions of N2O due to NH3 and NOx deposition were estimated to be of the same magnitude as the direct N2O emissions, the sum of direct and potential indirect amounting to ~3 g N2O-N/animal.day. If applied nationally, this would represent a contribution of N2O from Australian feedlots of 533Gg CO2-e or 2.2% of all Australian N2O emissions.
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Loh ZM, Wilson RL, Wild DA, Bieske EJ, Lisy JM, Njegic B, Gordon MS. Infrared Spectra and Ab Initio Calculations for the F-−(CH4)n (n = 1−8) Anion Clusters. J Phys Chem A 2006; 110:13736-43. [PMID: 17181329 DOI: 10.1021/jp0654112] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Infrared spectra of mass-selected F- -(CH4)n (n = 1-8) clusters are recorded in the CH stretching region (2500-3100 cm-1). Spectra for the n = 1-3 clusters are interpreted with the aid of ab initio calculations at the MP2/6-311++G(2df 2p) level, which suggest that the CH4 ligands bind to F- by equivalent, linear hydrogen bonds. Anharmonic frequencies for CH4 and F--CH4 are determined using the vibrational self-consistent field method with second-order perturbation theory correction. The n = 1 complex is predicted to have a C3v structure with a single CH group hydrogen bonded to F-. Its spectrum exhibits a parallel band associated with a stretching vibration of the hydrogen-bonded CH group that is red-shifted by 380 cm-1 from the nu1 band of free CH4 and a perpendicular band associated with the asymmetric stretching motion of the nonbonded CH groups, slightly red-shifted from the nu3 band of free CH4. As n increases, additional vibrational bands appear as a result of Fermi resonances between the hydrogen-bonded CH stretching vibrational mode and the 2nu4 overtone and nu2+nu4 combination levels of the methane solvent molecules. For clusters with n < or = 8, it appears that the CH4 molecules are accommodated in the first solvation shell, each being attached to the F- anion by equivalent hydrogen bonds.
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Affiliation(s)
- Z M Loh
- School of Chemistry, The University of Melbourne, Australia 3010
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Wilson RL, Loh ZM, Wild DA, Thompson CD, Schuder MD, Lisy JM, Bieske EJ. Infrared spectra of the Cl––C2H4 and Br––C2H4 anion dimers. Phys Chem Chem Phys 2005; 7:3419-25. [PMID: 16273142 DOI: 10.1039/b508731g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Infrared spectra of mass-selected Cl- -C2H4 and Br- -C2H4 complexes are recorded in the vicinity of the ethylene CH stretching vibrations (2700-3300 cm(-1) using vibrational predissociation spectroscopy. Spectra of both complexes exhibit 6 prominent peaks in the CH stretch region. Comparison with calculated frequencies reveal that the 4 higher frequency bands are associated with CH stretching modes of the C2H4 subunit, while the 2 weaker bands are assigned as overtone or combinations bands gaining intensity through interaction with the CH stretches. Ab initio calculations at the MP2/aug-cc-pVDZ level suggest that C2H4 preferentially forms a single linear H-bond with Cl- and Br- although a planar bifurcated configuration lies only slightly higher in energy (by 110 and 16 cm(-1), respectively). One-dimensional potential energy curves describing the in-plane intermolecular bending motion are developed which are used to determine the corresponding vibrational energies and wavefunctions. Experimental and theoretical results suggest that in their ground vibrational state the Cl- -C2H4 and Br- -C2H4 complexes are localized in the single H-bonded configuration, but that with the addition of modest amounts of internal energy, the in-plane bending wavefunction also has significant amplitude in the bifurcated structure.
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Affiliation(s)
- R L Wilson
- School of Chemistry, University of Melbourne, Parkville, 3010, Victoria, Australia
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Loh ZM, Tan KL, Hsu PP, Lu KS, Eng SP. Migrating esophageal foreign bodies. Rev Laryngol Otol Rhinol (Bord) 2005; 126:105-10. [PMID: 16180350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
UNLABELLED Ingested foreign bodies which migrate extraluminally, although rare in occurrence, are fraught with the potential to cause life-threatening complications. PURPOSE OF THE STUDY To discuss the management of this pathology. MATERIAL AND METHODS A series of four patients with such occurrences is presented. CONCLUSION A discussion on the safe management of such seemingly innocuous foreign bodies allows the authors to propose a therapeutical algorythm.
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Affiliation(s)
- Z M Loh
- Changi General Hospital, Department of Otolaryngology, Head & Neck Surgery, 2 Simei Street 3, Singapore 529889, Singapore
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Abstract
The rotationally resolved infrared photodissociation spectrum of Cl(-)-HD is measured in the HD stretch region. Two Sigma-Sigma bands are observed, corresponding to transitions from the ground state [the (nuHD = 0, n = 0) level] and first excited intermolecular bend state [the (nuHD = 0, n = 1) level]. The (nuHD = 0, n = 0) and (nuHD = 0, n = 1) states are predominantly associated with the linear Cl-...DH and Cl-...HD geometries, respectively. The spectrum is complicated by perturbative interactions between levels of the (nuHD = 0, n = 0) and (nuHD = 0, n = 1) rotational manifolds and between levels of the (nuHD = 1, n = 0) and (nuHD = 1, n = 1) rotational manifolds. A global fit to the transition frequencies, taking the lower and upper state perturbations into account, yields zero-order rotational and centrifugal distortion constants and allows us to establish that the (nuHD = 0, n = 1, J" = 0) level lies 13.7 cm(-1) above the (nuHD = 0, n = 0, J" = 0) level. Rovibrational energy level calculations performed using a recent ab initio potential energy surface confirm the picture emerging from the experimental data and provide good agreement with measured molecular parameters. The results emphasize the importance of quantum mechanical interconversion between two isomeric structures of a simple anion complex.
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Affiliation(s)
- R L Wilson
- School Of Chemistry, University of Melbourne, 3010 Victoria, Australia
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Affiliation(s)
- D. A. Wild
- School of Chemistry, University of Melbourne, Parkville 3010, Victoria, Australia
| | - P. S. Weiser
- School of Chemistry, University of Melbourne, Parkville 3010, Victoria, Australia
| | - Z. M. Loh
- School of Chemistry, University of Melbourne, Parkville 3010, Victoria, Australia
| | - E. J. Bieske
- School of Chemistry, University of Melbourne, Parkville 3010, Victoria, Australia
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