Baltic HYPE is a part of E-HYPE (v.3.1.4), a pan-European HYPE model developed by SMHI.
The possible changes modelled with E-HYPE that can occur by 2050s were driven by two aspects: changes in the climate forcing data using RCP8.5 and changes in socioeconomic variables using SSP1, SSP2, and SSP5.
The measures evaluated in this study utilize variability in reduction of nitrogen on a local scale. The BONUS Soils2Sea project conducted research on spatially differentiated regulation, exploiting the fact that the removal and retention of nutrients by biogeochemical processes or sedimentation in groundwater and surface water systems shows large spatial variations.
The impacts were evaluated against a baseline that represents sources and processes of the 2010s. To evaluate effectiveness of measures in future, SSP2 with 2050s climate was selected as a second, “future” baseline.
Climate impacts are evaluated using a mini-ensemble of 4 climate models using RCP8.5. The following models were selected: CCLM-MPI-ESM-LR, WRF-JPSL-CM5A-MR, RCA4-CNRM-CM5, RCA4-CanESM2. The natural variability was simulated using climate data from 1981 to 2010 for the current time period and from 2036 to 2065 for the 2050s time period. All values are presented as longterm averages over the respective 30-year period.
SSP1 (sustainability) describes is a world making relatively good progress towards sustain-ability, with sustained efforts to achieve development goals, while reducing resource intensity and fossil fuel dependency. For the Baltic Region it is assumed that there is a 10% reduction in agricultural land use and most of this is converted to forest. In agriculture, management plans to achieve goals of the EU Water Framework Directive (WFD) and all other plans are fully implemented. Consumption trends change towards less demand for meat. For sewage more sophisticated and comprehensive treatment are implemented. Air pollution is reduced through cleaner energy production and use of electric vehicles.
SSP2 (middle of the road) describes a world, where trends typical of recent decades continue with some progress towards achieving development goals, reductions in resource and energy intensity at historic rates, and slowly decreasing fossil fuel dependency. For the Baltic Region there is no change in agricultural land use. Trends in agriculture are towards larger farms, intensive farming, and industrialized and more effective agriculture. Management plans for reducing nutrient loadings from agriculture (WFD) are only partly implemented. For sewage, technology development and increased urbanization means reduced nutrient loadings from sewage. For air pollution NOx-emissions decrease. Hybrid and electric cars will be more common and therefore urban emissions will decrease.
SSP5 (fossil-fueled development) is a world that stresses conventional development oriented toward economic growth as the solution to social and economic problems through the pursuit of enlightened self-interest. The preference for rapid conventional development leads to a high energy demand, most of which is met with carbon based fuels. For the Baltic Region it is assumed that there is a 10% increase in agricultural land use and most of this taken from forest. The increasing agricultural land use is associated with higher livestock production within a global market. There will be fewer regulations of agricultural nutrient loadings, but improvements in production technologies. For sewage, there will be a higher amount of waste water because of the increased urbanization. Technologies to improve sewage treatments will increase in efficiency. For air pollution, technologies to reduce NOx pollution will continue but with a reduced rate compared to SSP1 and SSP2.
Measures targeting reduction of nitrogen (N) in groundwater aim to relocate the existing agricultural practice according to the N-reduction capacity, so that crops or practices with high N-leaching are moved to areas with high N-reduction and vice versa.
Measures targeting reduction of nitrogen (N) in surface water are set of measures that either increase the average transport time and thus increase the deposition of nutrients during the transport, or increase the transformation of nitrate into nitrogen gas and thereby completely remove it from the system before it reaches the mouth of the stream.
The work was partially supported by BONUS(http://www.bonusportal.org/), the joint Baltic Sea research and development programme (Art 185), through SOILS2SEA (/www.soils2sea.eu/) and MIRACLE (http://bonus-miracle.eu/) projects.