Which policies can stop large scale eutrophication?

During a few decades, many fresh and marine water areas have been seriously affected by eutrophication, due to increasing discharges of phosphorus (P) and nitrogen (N) from modern society. The aim of this paper is to discuss the policies that are used and have been suggested to reduce eutrophication, and the factors counteracting these efforts. Policy options to reduce the fluxes of nutrients from point and non-point sources are summarized. A number of processes and mechanisms counteract the control measures taken so far, namely: the growing world population, the increasing urbanization, the intensive land independent animal production, the over-consumption of N and P, the emissions of N to the atmosphere, and the losses of P from P-enriched sediments. It is concluded that the driving force for eutrophication, the losses of nutrients from food production, organic waste, sewage, sludge and ashes can be expected to increase during the coming decades, as the world population continues to grow. Strong policies are needed to promote birth control, and to stop over-consumption of N (animal protein) and unnecessary intake of P (food additives). There is a number of barriers to overcome to reduce large-scale eutrophication, but also a lot of space for new policies and innovation.