Eutrophication: Early warning signals, ecosystem-level and societal responses, and ways forward This article belongs to Ambio's 50th Anniversary Collection. Theme: Eutrophication

Eutrophication, i.e. nutrient over-enrichment, has been a topic for academic and societal debate for the past five decades both on land and in aquatic systems fed by nutrients as diffuse loading from agricultural lands and as wastewater from industrial and municipal point-sources. The use of nutrients (primarily nitrogen and phosphorus) in excess became a problem with the onset of large-scale production and use of artificial fertilizers after World War II, and the effects on the aquatic environment became obvious some two to three decades later. In this Perspective, four seminal papers on eutrophication are discussed in light of the current knowledge of the problem, including future perspectives and outlooks in the light of global climate change and the demand for science-based holistic ecosystem-level policies and management options.

Automated summary

Eutrophication, caused by excessive nutrients from agricultural lands and wastewater sources, has been a topic of debate for the past five decades. The use of nitrogen and phosphorus in excess, particularly after World War II, has had significant impacts on aquatic environments. This Perspective discusses four seminal papers on eutrophication in relation to current knowledge and future outlooks, emphasizing the need for science-based holistic ecosystem-level policies and management options in the context of global climate change.