Effects of EU policy and climate change on future delivery of nutrients to European seas

In Europe, intensive agriculture and high population density pose pressures on water resources quality and quantity. Water abstractions, intensive agriculture and wastewaters from urban areas and industries modify natural water availability and quality. The excess of nutrients (nitrogen and phosphorus) in rivers, lakes, groundwater and coastal waters impair water quality for human and ecosystem, and damage the goods and services provided by aquatic ecosystems. Environmental policy have been in place in the EU since the 1990s to reduce nutrient pollution and ensure sustainable water resource management and ecological quality, aiming at restoring and protecting all water bodies (2000/60/EC Water Framework Directive, WFD). Moreover, in recent years the ambitious goal to halve nutrient losses to the environment have been set by the EU Green Deal, Zero Pollution and Biodiversity Strategies. However, achieving this goal might require changes in the current land and water resource management.

Climate change, with shifts in amount, seasonal distribution, and intensity of rainfall, soil moisture regime, and runoff events, affects delivery of nutrients to the fresh and marine waters. In this study, by mean of scenario modelling, we explore the possible combined effects of EU policy measures and climate change on nutrients delivery to European seas at the time horizon of 2050 compared to current condition in Europe. We discuss on the one side the expected impacts of main EU policies (such as the Common Agricultural Policy (CAP), the updated legislation addressing greenhouse gases emissions (Fit For 55 package), and the revision of the Urban Waste Water Treatment Directive UWWTD), and on the other side we look at the concurrent role of climate change (scenario RCP 4.5) on nutrient load delivered to European seas, considering regional variability.

This study helps understanding the future trajectories of nutrient pollution in European fresh and coastal waters, highlighting the respective contribution of policy measures and climate change at the regional scale.