Despite improvements in some regions, nutrient loading from agriculture remains a major pressure on Europe's freshwaters, resulting in widespread eutrophication. The main consequences of nutrient enrichment include excess phytoplankton growth, increased frequency of cyanobacteria blooms, and depletion of dissolved oxygen, all leading to a decline in water quality and biodiversity. REFRESH provides new evidence for climate change impacts on lakes, showing that increased lake temperatures generally have a eutrophication-like effect.
As the impact of eutrophication and climate change follow the same pathways affecting nutrient availability and cascading effects in the food web, and given the high variability of both pressures, it is unlikely that their impacts can be disentangled in each particular case.
A review of more than 450 climate change adaptation measures related to water carried out by the REFRESH concludes that all measures leading to reduced nutrient losses from agriculture can be considered win-win measures as they meet environmental objectives set by the Water Framework Directive and will enhance the resilience of lake ecosystems under future climate change.