2 results
12 - Nitrogen flows and fate in urban landscapes
- from Part III - Nitrogen flows and fate at multiple spatial scales
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- By Anastasia Svirejeva-Hopkins, Potsdam Institute for Climate Impact Research, Stefan Reis, Centre for Ecology and Hydrology, Jakob Magid, Copenhagen University, Gabriela B. Nardoto, Universidade de Brasília, Sabine Barles, Université Paris Est – LATTS, Alexander F. Bouwman, Netherlands Environmental Assessment Agency, Ipek Erzi, TUBITAK Marmara Research Centre, Marina Kousoulidou, Aristotle University of Thessaloniki, Clare M. Howard, Centre for Ecology and Hydrology, Mark A. Sutton, Centre for Ecology and Hydrology
- Edited by Mark A. Sutton, NERC Centre for Ecology and Hydrology, UK, Clare M. Howard, NERC Centre for Ecology and Hydrology, UK, Jan Willem Erisman, Gilles Billen, Albert Bleeker, Peringe Grennfelt, Hans van Grinsven, Bruna Grizzetti
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- Book:
- The European Nitrogen Assessment
- Published online:
- 16 May 2011
- Print publication:
- 14 April 2011, pp 249-270
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- Chapter
- Export citation
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Summary
Executive summary
Nature of the problem
Although cities take only 1.5%–2% of the Earth's land surface, due to their dense population, settlement structure, transportation networks, energy use and altered surface characteristics, they dramatically change the regional and global nitrogen cycle. Cities import and concentrate Nr in the form of food and fuel, and then disperse it as air and water pollution to other ecosystems covering much larger areas.
Approaches
A mass-balance approach was used in order to quantify the fluxes of reactive nitrogen (Nr) in and out of cities.
Cities can be characterised either as a source of Nr (i.e. emitting large amounts as liquid or solid household waste, automobile exhaust, air pollution from power plants) or a sink of Nr (through importing more food, fossil fuels, etc., and having fewer emissions to the air and water).
Paris metropolitan area is used as a case study, which represents an evolving European capital with much available data.
Key findings/state of knowledge
The Paris Metropolitan Area changed from being a sink in the eighteenth and nineteenth centuries to a source of Nr today. Major changes in the city functioning occurred before 1950, but especially recent decades have been characterised by an unprecedented amplification of those changes.
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24 - Future scenarios of nitrogen in Europe
- from Part V - European nitrogen policies and future challenges
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- By Wilfried Winiwarter, International Institute for Applied Systems Analysis, Jean-Paul Hettelingh, National Institute for Public Health and the Environment, Alex F. Bouwman, Netherlands Environmental Assessment Agency, Wim de Vries, Wageningen University and Research Centre, Jan Willem Erisman, Energy Research Centre of the Netherlands, James Galloway, University of Virginia, Zbigniew Klimont, International Institute for Applied Systems Analysis, Allison Leach, University of Virginia, Adrian Leip, European Commission Joint Research Centre, Christian Pallière, Fertilizers Europe, Uwe A. Schneider, KlimaCampus, Hamburg University, Till Spranger, Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, Mark A. Sutton, Centre for Ecology and Hydrology, Anastasia Svirejeva-Hopkins, Potsdam Institute for Climate Impact Research, Klaas W. van der Hoek, National Institute for Public Health and the Environment, Peter Witzke, EuroCARE GmbH
- Edited by Mark A. Sutton, NERC Centre for Ecology and Hydrology, UK, Clare M. Howard, NERC Centre for Ecology and Hydrology, UK, Jan Willem Erisman, Gilles Billen, Albert Bleeker, Peringe Grennfelt, Hans van Grinsven, Bruna Grizzetti
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- Book:
- The European Nitrogen Assessment
- Published online:
- 16 May 2011
- Print publication:
- 14 April 2011, pp 551-569
-
- Chapter
- Export citation
-
Summary
Executive summary
Nature of the problem
The future effects of nitrogen in the environment will depend on the extent of nitrogen use and the practical application techniques of nitrogen in a similar way as in the past. Projections and scenarios are appropriate tools for extrapolating current knowledge into the future. However, these tools will not allow future system turnovers to be predicted.
Approaches
In principle, scenarios of nitrogen use follow the approaches currently used for air pollution, climate, or ecosystem projections. Short-term projections (to 2030) are developed using a ‘baseline’ path of development, which considers abatement options that are consistent with European policy. For medium-term projections (to 2050) and long-term projections, the European Nitrogen Assessment (ENA) applies a ‘storyline’ approach similar to that used in the IPCC SRES scenarios. Beyond 2050 in particular, such storylines also take into account technological and behavioral shifts.
Key findings/state of knowledge
The ENA distinguishes between driver-oriented and effect-oriented factors determining nitrogen use. Parameters that cause changes in nitrogen fixation or application are called drivers. In a driver-based approach, it is assumed that any variation of these parameters will also trigger a change in nitrogen pollution. In an effect-based approach, as the adverse effects of nitrogen become evident in the environment, introduction of nitrogen abatement legislation requiring the application of more efficient abatement measures is expected. This approach needs to rely on a target that is likely to be maintained in the future (e.g. human health). Nitrogen abatement legislation based on such targets will aim to counter any growth in adverse environmental effects that occur as a result of increased nitrogen application.
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