While just over a third of Switzerland (36 percent) had a very low likelihood (less than 20 percent) of seeing snow in the two decades from 1995 to 2005, that figure jumped to 44 percent from 2005 to 2017.
That is an area of 5,200 square kilometres, or about the size of the canton of Valais.
The results are based on analysis of satellite images of Switzerland carried out by researchers at the University of Geneva and at the United Nations GRID-Geneva environmental data centre.
A screen grab of the Swiss Data Cube tool used to carry out the research.
The study also shows that the area of Switzerland given over to eternal snow (where there is an 80 to 100 percent chance of snowfall) also shrank in the period studied – from 27 percent over the 1995–2005 period to 23 percent from 2005 to 2017.
The loss here is some 2,100 square kilometres, which is an area some seven times larger than the canton of Geneva.
The reduction in snow cover could be seen in the Jura region and in the Alps and was “particularly evident” in the Rhone Valley, said University of Geneva and GRID-Geneva researcher Grégory Giuliani in a press release.
Detailed information about snow cover is essential for policy planning on environmental issues, said the University of Geneva in its media statement.
“Beyond the economic issues related to tourism, other questions arise such as flood risk management or water supply, given the storage role that snow plays, retaining water in winter to release it in spring and summer,” the release stated.