Nutrients: Difference between revisions

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{{ComponentTemplate2
{{ComponentTemplate2
|Application=Global Environmental Outlook - GEO3 project; Global Environmental Outlook - GEO4 project; Millennium Ecosystem Assessment project; OECD Environmental Outlook to 2030 (2008) project; OECD Environmental Outlook to 2050 (2012) project; Resource Efficiency project; Rethinking Biodiversity Strategies (2010) project; Roads from Rio+20 (2012) project; SSP project; The Protein Puzzle (2011) project;
|Application=Roads from Rio+20 (2012) project; Shared Socioeconomic Pathways - SSP (2014) project; The Protein Puzzle (2011) project;
|IMAGEComponent=Scenario drivers; Agricultural economy and forestry; Agricultural systems; Agriculture and land use; Aquatic biodiversity; Emissions; Land cover and use; Livestock;
|IMAGEComponent=Drivers; Agricultural economy; Land-use allocation; Agriculture and land use; Aquatic biodiversity; Emissions; Land cover and land use; Livestock systems;
|KeyReference=Bouwman et al., 2013; Bouwman et al., 2009; Van Drecht et al., 2009;
|KeyReference=Beusen, 2014; Beusen et al., 2015; Beusen et al., 2016; Morée et al., 2013;
|Reference=Bouwman et al., 2011; Galloway et al., 2004; Zhang et al., 2010;  Diaz and Rosenberg, 2008; UNEP, 2002; Rabalais, 2002;
|Reference=Bouwman et al., 2013c; Galloway et al., 2004; Zhang et al., 2010;  Diaz and Rosenberg, 2008; UNEP, 2002; Rabalais, 2002; Beusen et al., 2015; Beusen et al., 2016
|InputVar=Population; GDP per capita; Land cover, land use - grid; Crop production; Fertilizer use efficiency; Animal stock; Livestock ration; Manure spreading fraction; Nitrogen deposition; Ammonia (NH3) loss; Fraction of urban population;
|InputVar=Population - grid; GDP per capita - grid; Land cover, land use - grid; Animal stocks; Livestock rations; Manure spreading fraction; Nitrogen deposition - grid; Actual crop and grass production - grid; Production system mix; Fertiliser use efficiency;
|OutputVar=Ammonia emissions from nutrients; N and P discharge to surface water;  Nutrient discharge to water surface; Soil N budget - grid; Soil P budget - grid;  
|OutputVar=NH3 emissions - grid; N and P discharge to surface water - grid;  Soil N budget - grid; Soil P budget - grid; N and P in wastewater discharge - grid;
|Description=Human activities have accelerated the earth’s biogeochemical nitrogen (N) and phosphorus (P) cycles by increasing the use of fertilisers in agriculture ([[Bouwman et al., 2011]]). The changes in global nutrient cycles have both positive and negative effects. Increased use of N and P fertilisers has allowed for an increase in the production of food required to support a rapidly growing human population, and increasing per-capita consumption of particularly meat and milk ([[Galloway et al., 2004]]). This has also contributed to ongoing increases in yields, thereby making agriculture economically viable on a land area that has expanded much less than the harvested output. A side effect is that significant fractions of the mobilised N are lost through the emission of ammonia (NH3), nitrous oxide (N2O) and nitric oxide (NO) to ambient air. Ammonia contributes to eutrophication and acidification when deposited on land. Nitric oxide plays a role in tropospheric ozone chemistry, and nitrous oxide is a potent greenhouse gas. Also, large fractions of the mobilised N and P in watersheds enter the groundwater through leaching, and are released to surface waters through groundwater transport and surface runoff. Subsequently, nutrients in streams and rivers are transported towards coastal marine systems, reduced by retention but augmented by releases from point sources, such as sewage systems and industrial facilities.
|Description=Human activity has accelerated the Earth’s biogeochemical nitrogen (N) and phosphorus (P) cycles through increasing fertiliser use in agriculture ([[Bouwman et al., 2013c]]). Increased use of N and P fertilisers has raised food production to support the rapidly growing world population, and increasing per capita consumption particularly of meat and milk ([[Galloway et al., 2004]]).  
This has resulted in numerous negative impacts on human health and the environment, such as groundwater pollution, loss of habitat and biodiversity, an increases in the frequency and severity of harmful algal blooms, eutrophication, hypoxia and fish kills ([[Diaz and Rosenberg, 2008]]; [[Zhang et al., 2010]]). Such harmful effects of eutrophication have been spreading rapidly around the world, with large-scale implications for biodiversity, water quality, fisheries and recreation, in both industrialised and developing regions ([[UNEP, 2002]]). In freshwater and coastal marine ecosystems it is not only the input of nutrients but also the disturbance of the stoichiometric balance of N, P and silica (Si) ([[Rabalais, 2002]]) that affect both the total plant production and the species that dominate the ecosystems.
 
To assess eutrophication as a consequence of changing population, economy and technological development, IMAGE 3.0 includes a nutrient model with three submodels:
The side effect is that significant proportions of the mobilised N are lost through ambient emissions of ammonia (NH<sub>3</sub>), nitrous oxide (N<sub>2</sub>O) and nitric oxide (NO). Ammonia contributes to eutrophication and acidification when deposited on land. Nitric oxide plays a role in tropospheric ozone chemistry, and nitrous oxide is a potent greenhouse gas. Moreover, large proportions of mobilised N and P in watersheds enter the groundwater through leaching, and are released to surface waters through groundwater transport and surface runoff. Subsequently, nutrients in streams and rivers are transported to coastal marine systems, reduced by retention but augmented by releases from point sources, such as sewerage systems and industrial facilities.
# The Wastewater model (See figure on the right I), which generates nutrient flows in wastewater discharges;
 
# The Soil nutrient budget model (See figure on the right II), describing all input and output of N and P in soil compartments;
This has resulted in negative impacts on human health and the environment, such as groundwater pollution, loss of habitat and biodiversity, an increases in the frequency and severity of harmful algal blooms, eutrophication, hypoxia and fish kills ([[Diaz and Rosenberg, 2008]]; [[Zhang et al., 2010]]). The harmful effects of eutrophication have spread rapidly around the world, with large-scale implications for biodiversity, water quality, fisheries and recreation, in both industrialised and developing regions ([[UNEP, 2002]]). Input of nutrients in freshwater and coastal marine ecosystems, also disturbs the stoichiometric balance of N, P and Si (silicon) ([[Rabalais, 2002]]) affecting total plant production and the species composition in ecosystems.
# The Nutrient environmental fate model (See figure on the right III), which describes the fate of soil nutrient surpluses and wastewater nutrients in the aquatic environment.
 
To assess eutrophication as a consequence of increasing population, and economic and technological development, IMAGE 3.0 includes a nutrient model ([[Beusen, 2014]]; [[Beusen et al., 2015]]; [[Beusen et al., 2016]]), which comprises three sub-models:
# Wastewater module calculating nutrient flows in wastewater discharges (Figure Flowchart, top);
# Soil nutrient budget module describing all input and output of N and P in soil compartments (Figure Flowchart, middle);
# Nutrient environmental fate describing the fate of soil nutrient surpluses and wastewater nutrients in the aquatic environment (Figure Flowchart, bottom).
|ComponentCode=N
|ComponentCode=N
|FrameworkElementType=state component
|FrameworkElementType=state component
}}
}}

Revision as of 14:36, 2 November 2016

Key policy issues

  • How will the increasing use of fertilisers affect terrestrial and marine ecosystems, with possible consequences for human health?
  • To what extent can the negative impacts be reduced by more efficient nutrient management and wastewater treatment, while retaining the positive effects on food production and land productivity?

Introduction