A forthcoming study has added to worries that the Alpine ski industry will be badly affected by global warming, the British weekly New Scientist reports on Wednesday.

A "dramatic step-like drop" in the amount of snow falling in the western European mountain chain occurred in the late 1980s and since then snowfall has never recovered, it says.

The evidence has been compiled by researcher Christoph Marty at the Swiss Federal Institute for Snow and Avalanche Research.

Previous data have suggested that Alpine snowfall has been affected by rising temperatures, particularly at lower-altitude resorts where snow-making machines are now widely deployed.

Marty casts a wider net, though, spanning snowfall trends over 60 years from 34 weather stations between 200 and 1,800 metres (650 and 6,300 feet) above sea level. The last 10 years of data are new and until now have not been analysed

The average number of snow days over the last 20 winters is lower than at any time since records began more than 100 years ago, and in some years the amount that fell was 60 percent lower than was typical in the early 1980s, Marty found.

The future of winter tourism in this region looks grim, Marty told AFP.

"It doesn't look too good. There is a very, very small chance of a return" to previous snow levels, he said.

"This last winter was relatively good, for places above 1,200 metres (3,900 feet) above sea level, but for other places it was poor."

His work will appear in the US peer-reviewed journal Geophysical Research Letters.