In a winter sports industry that saw rapid expansion over the past decades, artificial snow now  plays a central role that typically covers 15 – 25% of a resort’s operating budget, although costs can be as high as 50% . The production of artificial snow is an extremely costly process for winter sports resorts. In the Alps for example, almost all resorts rely on artificial snow . This reliance is more critical than merely extending the season or improving the tourists’ skiing experience. Because of climatic changes, many resorts can no longer rely on natural snow at all and snowmaking equipment is now ubiquitous in the Alps.
There are two types of snowmaker in common use: snow lances and fan guns. Both machines use a set of nozzles of various sizes to produce fine mist from a mixture of water and air. Because the freezing process depends on environmental parameters, a pre-programmed algorithm controls nozzle settings, the air/water mixture and the throughout.
Both types of snowmaker rely on temperatures low enough for the water mist to freeze. Additives can be mixed with the water to increase the operating temperature. These additives, mostly ice-nucleating proteins (INPs), facilitate nucleation, thus increasing the maximum temperatures artificial snow can be produced in.
The use of INPs is controversial. Although their use is widespread e.g. in the US, they are currently banned in Europe. However, the current rate of climate change suggests that the ability to produce artificial snow at higher temperatures is vital for the survival of the European winter sports industry.