For years, the lake, known locally as Lac Léman and shared between Switzerland and France, has been falling victim of global warming, in pretty much the same way as melting glaciers. 

Its water had reached an average temperature of 13.6C in 2022, according to a recent report by the International Commission for the Protection of the Waters of Lake Geneva (CIPEL). 

While this may be welcome news for swimmers, such a drastic temperature change is damaging the lake’s delicate natural ecosystem.

That’s because warm water on top and cooler water trapped below creates less oxygen, which, in turn, can kill fish and other marine organisms that can no longer breathe underneath the surface.

In view of this alarming deterioration, CIPEL is committed to strengthening “the implementation of effective conservation measures for Lake Geneva,” the organisation said.

Action is needed because “in a context of climate change, Lake Geneva is an invaluable strategic resource, and it is essential to guarantee its good quality,” CIPEL  pointed out.

The findings of its report are important, the organisation added, because they “provide a crucial basis for policy makers, scientists, and the local community in the protection of our precious lake ecosystem.”