Increasing the cost-effectiveness of nutrient reduction targets using different spatial scales

In this paper, we investigate the potential gains in cost-effectiveness from changing spatial scale at which nutrient reduction targets are set for Baltic Sea, with particular focus on loadings agriculture. The costs of achieving loading reductions compared across five levels scale, namely entire Sea; marine basin level; country watershed and grid square level. A novel highly-disaggregated model, represents decreases agricultural profits, changes root zone N concentrations transport to Sea is used. model includes 14 basins, countries, 117 watersheds 19,023 10-by-10 km squares. main result emerges that there a large variation total cost program depending targeting: example, 40% loads, Sea-wide target nearly three times lower than smallest level (grid square). These results have important implications both domestic international policy design water quality improvements where non-point pollution key stressor quality.