Using a map-based assessment tool for the development of cost-effective WFD river basin action programmes in a changing climate.

For the 2nd and 3rd river basin management cycles (2015-2027) of the Water Framework Directive (WFD), EU Member States are required to fully integrate climate change into the process of river basin management planning (RBMP). Complying with the main WFD objective of achieving 'good ecological status' in all water bodies in Denmark requires Programmes of Measures (PoMs) to reduce nitrogen (N) pollution from point and diffuse sources. Denmark is among the world's most intensively farmed countries and in spite of thirty years of significant policy actions to reduce diffuse nutrient emissions, there is still a need for further reductions. In addition, the impacts of climate change are projected to lead to a situation where nutrient loads will have to be reduced still further in comparison to current climate conditions. There is an urgent need to address this challenge in WFD action programmes in order to develop robust and cost-effective adaptation strategies for the next WFD RBMP cycles. The aim of this paper is to demonstrate and discuss how a map-based PoMs assessment tool can support the development of adaptive and cost-effective strategies to reduce N losses in the Isefjord and Roskilde Fjord River Basin in the north east of Denmark. The tool facilitates assessments of the application of agri-environmental measures that are targeted towards low retention agricultural areas, where limited or no surface and subsurface N reduction takes place. Effects of climate change on nitrate leaching were evaluated using the dynamic agro-ecosystem model 'Daisy'. Results show that nitrate leaching rates increase by approx. 25% under current management practices. This impact outweighs the expected total N reduction effect of Baseline 2015 and the first RBMP in the case study river basin. The particular PoMs investigated in our study show that WFD N reduction targets can be achieved by targeted land use changes on approx. 4% of the agricultural area under current climate conditions and approx. 9% of the agricultural area, when projected climate change impacts on nitrate leaching rates are included in the assessment. The study highlights the potential of the PoMs assessment tool to assist in evaluation of alternative WFD RBMP scenarios to achieve spatially targeted and cost-effective reductions of N loads at catchment scale in the context of a changing climate.

Linking climate change mitigation and coastal eutrophication management through biogas technology: Evidence from a new Danish bioenergy concept.

The interest in sustainable bioenergy solutions has gained great importance in Europe due to the need to reduce GHG emissions and to meet environmental policy targets, not least for the protection of groundwater and surface water quality. In the Municipality of Solrød in Denmark, a novel bioenergy concept for anaerobic co-digestion of food industry residues, manure and beach-cast seaweed has been developed and tested in order to quantify the potential for synergies between climate change mitigation and coastal eutrophication management in the Køge Bay catchment. The biogas plant, currently under construction, was designed to handle an annual input of up to 200,000 t of biomass based on four main fractions: pectin wastes, carrageenan wastes, manure and beach-cast seaweed. This paper describes how this bioenergy concept can contribute to strengthening the linkages between climate change mitigation strategies and Water Framework Directive (WFD) action planning. Our assessments of the projected biogas plant indicate an annual reduction of GHG emissions of approx. 40,000 t CO2 equivalents, corresponding to approx. 1/3 of current total GHG emissions in the Municipality of Solrød. In addition, nitrogen and phosphorous loads to Køge Bay are estimated to be reduced by approx. 63 t yr.(-1) and 9 tyr.(-1), respectively, contributing to the achievement of more than 70% of the nutrient reduction target set for Køge Bay in the first WFD river basin management plan. This study shows that anaerobic co-digestion of the specific food industry residues, pig manure and beach-cast seaweed is feasible and that there is a very significant, cost-effective GHG and nutrient loading mitigation potential for this bioenergy concept. Our research demonstrates how an integrated planning process where considerations about the total environment are integrated into the design and decision processes can support the development of this kind of holistic bioenergy solutions.