Archive for the category: Feature Presentation

Adrian Leip, Gema Carmona-Garcia, Simone Rossi

¹ European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via Fermi 2749, TP 266/040

I-21027 ISPRA (VA), Italy, https://ec.europa.eu/jrc/en, adrian.leip@jrc.ec.europa.eu

Abstract

We assessed the question of side effects and of the accountability of mitigation measures in the Agriculture, Forestry, and Other Land Uses (AFOLU) sector in national greenhouse gas inventories, proposing a novel classification system of available mitigation measures on the basis of ‘mitigation strategies’ and ‘mitigation mechanisms’. While the first differentiates measures which require collection of data from those for which specific emission factors or parameters need to be developed, the second groups mitigation measures according to the ‘term’ that is exploited to achieve emission reductions. We find that current IPCC methodologies provide a good basis to account for the majority of mitigation measures. Most of them will be reflected in national greenhouse gas inventories if default tier 1 approaches or (in some cases) national level tier 2 approaches are used (according to IPCC terminology). Efforts should be concentrated on improving data availability especially about management options, which is often the major obstacle in accounting for the effect of mitigation efforts. Examples include mitigation measures focusing on the improvement of feed intake of animals, or actions aimed at incrementing the soil organic carbon stock in agricultural soils through appropriate management practices. We conclude that simple farm level tools may have a good potential in collecting the data required, and offer the opportunity of full flexibility for the farmers to select concrete farm practice changes and monitor their performance.

Enrico Dammers¹, M. Palm², Martin Van Damme³, Mark W. Shephard⁴, Lieven Clarisse³, Karen E. Cady-Pereira⁵, Simon Whitburn³, Pierre Francois Coheur³, M.Schaap⁶ and Jan Willem Erisman^1,7

¹ Cluster Earth and Climate, Department of Earth Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands. E.Dammers@vu.nl

2 Institut für Umweltphysik, University of Bremen, Bremen, Germany

3 Spectroscopie de l’Atmosphère, Service de Chimie Quantique et Photophysique, Université Libre de Bruxelles (ULB), Brussels, Belgium

4 Environment Canada, Toronto, Ontario, Canada

5 Atmospheric and Environmental Research (AER), Lexington, Massachusetts, USA

6 TNO, Climate Air Sustainability, Utrecht, the Netherlands

7 Louis Bolk Institute, Driebergen, the Netherlands

Abstract

Global emissions of reactive nitrogen have increased due to human activities and are estimated to be a factor four larger than pre-industrial levels. Concentration levels of NO_x are declining, but ammonia (NH₃) levels are increasing globally. At its current concentrations NH₃ poses a large threat to both the environment and human health. Still relatively little is known about the total budget as well as the global distribution. Surface observations are sparsely available, mostly for north-western Europe, the United States and China, and are limited by the high costs and poor spatial and temporal resolution. The lifetime of atmospheric NH₃ is short, in the range of several hours to a few days and the existing surface measurements are not sufficient to estimate global concentrations. Space-based InfraRed-sounders such as the Infrared Atmospheric Sounding Interferometer (IASI) and the Cross-track Infrared Sounder (CrIS) enable global observations of atmospheric NH₃ which can overcome the limitations of existing surface observations. One challenge with satellite NH₃ retrievals is that they are complex and require extensive validation. Presently only a limited number of satellite NH₃ validation campaigns have been performed with limited spatial, vertical and temporal coverage. In this study we demonstrate the use of a recently developed retrieval methodology for ground-based Fourier Transform Infrared Spectroscopy (FTIR) instruments to obtain vertical concentration profiles of NH₃. We will use the retrieved profiles from eight stations with a range of NH₃ pollution levels to validate satellite NH₃ products.

Andrea Móring^1,2, Massimo Vieno², Ruth M. Doherty³, Celia Milford^4,5, Eiko Nemitz², Marsailidh M. Twigg², Mark A. Sutton²

¹ University of Edinburgh, High School Yards, Edinburgh, United Kingdom, EH8 9XP, andrea.moring@ed.ac.uk
² Centre for Ecology & Hydrology, Bush Estate, Penicuik, United Kingdom, EH26 0QB
³ University of Edinburgh, The King’s Buildings, Alexander Crum Brown Road, Edinburgh, United Kingdom, EH9 3FF
⁴ Associate Unit CSIC University of Huelva ”Atmospheric Pollution”, CIQSO, University of Huelva, Huelva, Spain, E21071
⁵ Izaña Atmospheric Research Center, AEMET, Joint Research Unit to CSIC “Studies on Atmospheric Pollution”, Santa Cruz de Tenerife, Spain

Abstract

In this study a process-based ammonia (NH₃) exchange model for a grazed field has been described and evaluated. The presented model is based on a patch-scale NH₃ exchange model, GAG (Generation of Ammonia from Grazing), which has been here extended to the field scale. GAG accounts for the total ammoniacal nitrogen and water content of the soil as well as the soil pH under a single urine patch. The new, field scale model combined multiple runs of the patch-scale model including both urine-affected and unaffected areas. The field-scale model was tested over two modelling periods, using NH₃ flux measurements taken at an intensively managed grassland, Easter Bush, UK. The model represented well the observed fluxes. It was found that the temporal evolution of the NH₃ exchange flux was dominated by the NH₃ emission from the urine patches. The results also showed that the evolution of NH₃ emission from urine patches deposited in different time steps could be substantially different: in some cases the first high NH₃ emission peak occurred a day or two days after the deposition of the given urine patch. Furthermore, according to our findings, NH₃ fluxes over the field in a given day could be considerably affected by the NH₃ emission from urine patches deposited several days earlier. The approach is designed to provide a balance between simplicity and process representation to allow it to be ultimately applied in regional scale atmospheric emission, transport and deposition modelling.

David R. Kanter^1,2, Sonali P. McDermid^1,3, Larissa Nazarenko³

¹Department of Environmental Studies, New York University, 285 Mercer Street, New York, NY, 10003, USA

²Agriculture and Food Security Center, Columbia University, 61 Route 9w, Palisades, NY, 10964, USA

³NASA Goddard Institute for Space Sciences, 2880 Broadway, New York, NY, 10025, USA

Abstract

Nitrous oxide (N₂O) is an important greenhouse gas and ozone depleting substance as well as a key component of the nitrogen cascade. While emissions scenarios indicating the range of N₂O’s potential future contributions to radiative forcing are widely available, the impact of these emissions scenarios on future stratospheric ozone depletion is less clear. This is because N₂O’s ozone destructiveness is partially dependent on tropospheric warming, which affects ozone depletion rates in the stratosphere. Consequently, in order to understand the possible range of stratospheric ozone depletion that N₂O could cause over the 21^st century, it is important to decouple the greenhouse gas emissions scenarios and compare different emissions trajectories for individual substances (e.g. business-as-usual carbon dioxide (CO₂) emissions versus low emissions of N₂O). This study is the first to follow such an approach, running a series of experiments using the NASA Goddard Institute for Space Sciences ModelE2 atmospheric sub-model. We anticipate our results to show that stratospheric ozone depletion will be highest in a scenario where CO₂ emissions reductions are prioritized over N₂O reductions, as this would constrain ozone recovery while doing little to limit stratospheric NO_x levels (the breakdown product of N₂O that destroys stratospheric ozone). This could not only delay the recovery of the stratospheric ozone layer, but might also prevent a return to pre-1980 global average ozone concentrations, a key goal of the international ozone regime. Accordingly, we think this will highlight the importance of reducing emissions of all major greenhouse gas emissions, including N₂O, and not just a singular policy focus on CO₂.

Groenestein, C.M.¹, Hutchings, N.J.² , Haenel, H.D.³, Amon, B.⁴, Menzi, H.⁵, Mikkelsen, M.H.⁶, Misselbrook, T.H.⁷, van Bruggen, C.⁸, Kupper, T.⁹, Webb, J.¹⁰

¹ Wageningen UR Livestock Research, De Elst 1, 6708 WD Wageningen, www.wageningenur.nl/en/livestockresearch, karin.groenestein@wur.nl

² Dept. of Agroecology, Aarhus University, Research Centre Foulum, 8830 Tjele, Denmark

³ Thünen Institute of Climate-Smart Agriculture (TI-AK), Bundesallee 50,38116 Braunschweig, Germany

⁴ Leibniz Institute for Agricultural Engineering, Max-Eyth-Allee 100, 14469 Potsdam, Germany

⁵ Agroscope, Inst. For Livestock Sciences, P.O. Box 64, CH-1725 Posieux, Switzerland

⁶ Dept. of Environmental Science, Frederiksborgvej 399, 4000 Roskilde, Denmark

⁷ Sustainable Soils and Grassland Systems, Rothamsted Research, North Wyke, Devon, UK, EX20 2SB

⁸ Organisation, address, city, state, postcode, website, Email

⁹ Bern University of Applied Sciences, School of Agricultural, Forest and Food Sciences Laenggasse 85 CH-3052 Zollikofen

¹⁰ Ricardo Ltd, Gemini Building, Harwell, UK. OX11

Abstract

Ammonia (NH₃) emissions from livestock production systems can be substantial but difficult to measure. Here we explore the relationship between NH₃ emissions, the emission intensity (NH₃-N emitted/product N) and the more easily measured feed Nitrogen Use Efficiency (NUE). Using a conceptual model, we find that the relationship between emission intensity and NUE is equivalent to that between NH₃-N emission and feed N intake. Furthermore, there is a linear relationship between the two, with a slope that is dependent on characteristics of the animal and its feed, and the manure management system. This is illustrated using data taken from the emission inventories of six European countries, which found a linear relationship, with much variation within a commodity type. Using the same data, we show how the effects of animal and feed characteristics can be separated from those of the manure management system.

Atul K Jain¹, Prasanth Meiyappan¹ and Joanna I House²

¹Department of Atmospheric Sciences, University of Illinois, Urbana, IL 61801, USA

²Department of Geography, Cabot Institute, University of Bristol, Bristol, BS8 1SS, UK

Abstract

We estimate the impacts of nitrogen limitation on the CO₂ emissions from land use and land-use change (LULUC), including wood harvest, for the period 1900-2100. We use a land-surface model that includes a fully coupled carbon and nitrogen cycle, and accounts for forest regrowth processes following agricultural abandonment and wood harvest. Future projections are based on the four Representation Concentration Pathways used in the IPCC Fifth Assessment Report. Results show that excluding nitrogen limitation will underestimate global LULUC emissions by 34-52 PgC (20-30%) during the 20th century and by 128-187 PgC (90-150%) during the 21st century. The underestimation increases with time because: (1) Projected annual wood harvest rates from forests summed over the 21st century are 380-1080% higher compared to those of the 20th century, resulting in more regrowing secondary forests, (2) Nitrogen limitation reduces the CO₂ fertilization effect on net primary production of regrowing secondary forests following wood harvest and agricultural abandonment, and (3) Nitrogen limitation effect is aggravated by the gradual loss of soil nitrogen from LULUC disturbance. Our study implies that: (1) Nitrogen limitation of CO₂ uptake is substantial and sensitive to nitrogen inputs, (2) If LULUC emissions are larger than previously estimated in studies without nitrogen limitation, then meeting the same climate mitigation target would require an equivalent additional reduction of fossil fuel emissions, and (3) The effectiveness of land-based mitigation strategies will critically depend on the interactions between nutrient limitations and secondary forests resulting from LULUC.