Coastal eutrophication in Europe caused by production of energy crops
Wijnen, J. van; Ivens, W.P.M.F. ; Kroeze, C. ; Löhr, A.J. - \ 2015
Science of the Total Environment 511 (2015). - ISSN 0048-9697 - p. 101 - 111.
biomass production - marine ecosystems - future-trends - biofuels - land - rivers - export - agriculture - nitrogen - waters
In Europe, the use of biodiesel may increase rapidly in the coming decades as a result of policies aiming to increase the use of renewable fuels. Therefore, the production of biofuels from energy crops is expected to increase as well as the use of fertilisers to grow these crops. Since fertilisers are an important cause of eutrophication, the use of biodiesel may have an effect on the water quality in rivers and coastal seas. In this study we explored the possible effects of increased biodiesel use on coastal eutrophication in European seas in the year 2050. To this end, we defined a number of illustrative scenarios in which the biodiesel production increases to about 10–30% of the current diesel use. The scenarios differ with respect to the assumptions on where the energy crops are cultivated: either on land that is currently used for agriculture, or on land used for other purposes. We analysed these scenarios with the Global NEWS (Nutrient Export from WaterSheds) model. We used an existing Millennium Ecosystem Assessment Scenario for 2050, Global Orchestration (GO2050), as a baseline. In this baseline scenario the amount of nitrogen (N) and phosphorus (P) exported by European rivers to coastal seas decreases between 2000 and 2050 as a result of environmental and agricultural policies. In our scenarios with increased biodiesel production the river export of N and P increases between 2000 and 2050, indicating that energy crop production may more than counterbalance this decrease. Largest increases in nutrient export were calculated for the Mediterranean Sea and the Black Sea. Differences in nutrient export among river basins are large.
Increasing eutrophication in the coastal seas of China from 1970 to 2050
Strokal, M. ; Yang, H. ; Zhang, Y. ; Kroeze, C. ; Li, L. ; Luan, S. ; Wang, H. ; Yang, S. - \ 2014
Marine Pollution Bulletin 85 (2014)1. - ISSN 0025-326X - p. 123 - 140.
pearl river - future-trends - nutrient export - yangtze estuary - algal blooms - food-chain - management - nitrogen - waters - phosphorus
We analyzed the potential for eutrophication in major seas around China: the Bohai Gulf, Yellow Sea and South China Sea. We model the riverine inputs of nitrogen (N), phosphorus (P) and silica (Si) to coastal seas from 1970 to 2050. Between 1970 and 2000 dissolved N and P inputs to the three seas increased by a factor of 2–5. In contrast, inputs of particulate N and P and dissolved Si, decreased due to damming of rivers. Between 2000 and 2050, the total N and P inputs increase further by 30–200%. Sewage is the dominant source of dissolved N and P in the Bohai Gulf, while agriculture is the primary source in the other seas. In the future, the ratios of Si to N and P decrease, which increases the risk of harmful algal blooms. Sewage treatment may reduce this risk in the Bohai Gulf, and agricultural management in the other seas.
The increasing impact of food production on nutrient export by rivers to the Bay of Bengal 1970–2050
Sattar, M.A. ; Kroeze, C. ; Strokal, M. - \ 2014
Marine Pollution Bulletin 80 (2014)1-2. - ISSN 0025-326X - p. 168 - 178.
harmful algal blooms - management strategies - coastal nitrogen - shrimp culture - future-trends - sewage-sludge - water-quality - india - soil - eutrophication
The objective of this study is to assess the impact of food production on river export of nutrients to the coastal waters of the Bay of Bengal in the past (1970 and 2000) and the future (2030 and 2050), and the associated potential for coastal eutrophication. We model nutrient export from land to sea, using the Global NEWS (Nutrient Export from WaterSheds) approach. We calculate increases in river export of N and P over time. Agricultural sources account for about 70–80% of the N and P in rivers. The coastal eutrophication potential is high in the Bay. In 2000, nutrient discharge from about 85% of the basin area of the Bay drains into coastal seas contributes to the risk of coastal eutrophication. By 2050, this may be 96%. We also present an alternative scenario in which N and P inputs to the Bay are 20–35% lower than in the baseline.
Nitrous Oxide (N2O) emissions from human waste in 1970-2050
Strokal, M. ; Kroeze, C. - \ 2014
Current Opinion in Environmental Sustainability 9-10 (2014). - ISSN 1877-3435 - p. 108 - 121.
water treatment-plant - coastal waters - climate-change - future-trends - sewage-sludge - anthropogenic nitrogen - reactive nitrogen - nutrient export - surface-water - united-states
Nitrous oxide (N2O) is an important contributor to climate change. Human waste is an important source of N2O emissions in several world regions, and its share in global emissions may increase in the future. In this paper we, therefore, address N2O emission from human waste: collected (from treatment and from sewage discharges) and uncollected waste. We review existing literature on emissions and emission factors, and present region-specific estimates of N2O emissions and their past and future trends. We show that human waste may became an important source of N2O emissions in the coming years as a result of increasing urbanization. About two-thirds of the global emissions are from uncollected waste, and about half from South Asia. We argue that more research is needed to improve emission factors.
Environmental Assessment of Management Options for Nutrient Flows in the Food Chain in China
Ma, L. ; Wang, F. ; Zhang, W. ; Ma, W. ; Velthof, G.L. ; Qin, W. ; Oenema, O. ; Zhang, F. - \ 2013
Environmental Science and Technology 47 (2013)13. - ISSN 0013-936X - p. 7260 - 7268.
global phosphorus flows - crop system management - integrated assessment - reactive nitrogen - future-trends - agriculture - consumption - losses - perspective - security
The nitrogen (N) and phosphorus (P) costs of food production have increased greatly in China during the last 30 years, leading to eutrophication of surface waters, nitrate leaching to groundwater, and greenhouse gas emissions. Here, we present the results of scenario analyses in which possible changes in food production–consumption in China for the year 2030 were explored. Changes in food chain structure, improvements in technology and management, and combinations of these on food supply and environmental quality were analyzed with the NUFER model. In the business as usual scenario, N and P fertilizer consumption in 2030 will be driven by population growth and diet changes and will both increase by 25%. N and P losses will increase by 44 and 73%, respectively, relative to the reference year 2005. Scenarios with increased imports of animal products and feed instead of domestic production, and with changes in the human diet, indicate reductions in fertilizer consumption and N and P losses relative to the business as usual scenario. Implementation of a package of integrated nutrient management measures may roughly nullify the increases in losses in the business as usual scenario and may greatly increase the efficiency of N and P throughout the whole food chain.
Spatial and temporal variability of nutrient retention in river basins: A global inventory
Tysmans, D.J.J. ; Löhr, A.J. ; Kroeze, C. ; Ivens, W.P.M.F. ; Wijnen, T.K. van - \ 2013
Ecological Indicators 34 (2013). - ISSN 1470-160X - p. 607 - 615.
coastal zone - future-trends - export - nitrogen - phosphorus - explicit - denitrification - eutrophication - watersheds - pollution
Nutrient export by rivers may cause coastal eutrophication. Some river basins, however, export more nutrients than others. We model the Basin-Wide Nutrient Export (BWNE) Index, defined as nutrient export by rivers as percentage of external nutrient inputs in the basins. We present results for rivers worldwide for the period 1970–2050. The results indicate that nutrient retentions differ largely among basins. They indicate that BWNE increases with nutrient inputs to the land, indicating that the percentage of, for instance, fertilizers exported to sea increases with fertilization rate. We argue that a better understanding of the BWNE Index might help to identify where measures and technologies to reduce nutrient inputs to coastal waters are most effective.