Cannons pumping out artificial snow have become part of the landscape in many ski resorts, but there is growing concern about their effect on the environment.

Claire Doole: "The debate is becoming heated"

The Technical Director of Davos ski resort, Markus Good, says the cannons make economic sense.

"Firstly global warming means there is no guarantee of snow the whole season and, secondly, because of the increasing numbers of skiers we need that little bit of extra mechanical help to improve the quality and cover of the snow. Man-made snow is really the only solution."

Snow cannons have become part of the landscape

The World Wide Fund for Nature - one of the many powerful environmental groups in Switzerland - is unconvinced. Head of the Graubunden office, Peter Luthi, says the problem is the whole infrastructure needed to maintain the snow machines.

"Snow cannons cause irreparable damage to the mountains. They are a drain on the region's water and electricity supplies. Huge unsightly reservoirs have to be dug, and the pipelines carrying the water and air to the cannons scar the countryside for years before the grass grows back."

The latest potential environmental threat comes in a packet. Ski operators are increasingly using commercial products - chemicals which make fake snow when the outside temperatures is too warm to use air and water.

The debate is becoming so heated that the Swiss government has asked the Snow Institute in Davos to intervene.

The region lives from winter tourism

Usually the institute concentrates on real snow - measuring its quantity and quality, but project leader, Veronica Stoekli says examining the environmental impact of fake snow is a real challenge:

"It is important to bring facts into the controversial discussion which has been going on for years - to say what is going to happen to the vegetation, what is going to happen to the soil by changed soil cover."

The region relies on winter tourism, and without the skiers and snowboarders the economy would suffer badly. Making fake snow may be expensive but the director of Graubunden tourism, Olivier Federspiel, says it is a price that has to be paid.

Claire Doole: "It leaves the skiers cold"

"It is an economic problem. It costs a lot of money to produce artificial snow. We would prefer to use real snow but as far as environmental problems you can't expect one small region to solve an international problem.

Fake snow may be the hot topic amongst environmentalists, scientists and ski chiefs, but it leaves the skiers cold. The general opinion on the slopes is that they just want to ski.