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Introduction
Since the 1990s the potential vulnerability of ski
tourism to climate change has repeatedly received
attention in the media, in the marketing activities of ski
resorts, and not least in scientific discussions concern-
ing the future of winter tourism (Abegg 1996; Hall and
Higham 2005; Scott et al 2005). The latest OECD
report on Climate change in the European Alps (Agrawala
2007), published during the excessively warm winter of
2006–2007, with +3.2°C above mean for December 2006
to February 2007 in Tyrol (ZAMG 2007), suggests that
due to global warming the line of natural snow reliabili-
ty will rise by about 150 m per 1°C of warming. Conse-
quently, the European Alps are expected to experience
a loss of snow reliability, especially for low-elevation
resorts, and a concentration of ski tourism at elevations
higher than 1800–2000 m (Abegg et al 2007). Neverthe-
less, these projections may be of little consequence; in
Austria, for example, 59% of the skiing area is covered
by snowmaking facilities (FSÖ 2007). Some resorts have
already covered most of their slopes (>80 %; Figure 1).
However, in the case of Tyrol, there does not
appear to be any link between a ski area’s elevation and
the degree of snowmaking coverage (Figure 1). This is
confirmed by the results of qualitative interviews with
ski area operators as well as manufacturers of snowmak-
ing and skilift technology, making clear that the contin-
uing diffusion process of snowmaking is driven by dif-
ferent factors. There is a complex bundle of driving fac-
tors and background variables that influence the
diffusion of snowmaking in Austria (see below, section
on factors influencing the diffusion of snowmaking),
which, due to the lack of adequate data, are only verifi-
able with the help of qualitative approaches. The one-
dimensional perspective—climate change is responsible
for the diffusion of snowmaking—would be too simple
to capture the complexity of the phenomenon. Howev-
er, Wolfsegger et al (2007) has shown that snowmaking
is the dominant strategy of ski area managers for cop-
ing with projected climate change. This strategy proved
useful even in the extraordinarily warm winter season
of 2006–2007, also at low-altitude resorts with intensi-
fied snowmaking facilities (Figure 2). The most impor-
tant question in the future will be whether it is possible
to produce enough artificial snow at an acceptable cost
level (Scott et al 2003).
In order to be able to differentiate between natural
and man-made snow reliability, the latter should be des-
ignated as technical snow reliability. Studies including
snowmaking and a complex snow model have been
done in Canada (Scott et al 2003, 2006), Australia
(Hennessy et al 2003), Scotland (Harrison et al 2005),
and Switzerland (Teich et al 2007). These complex
models require high resolution climate data that may
not be available everywhere. Consequently, Steiger
(2007) developed a method that closes the gap between
a very simple approach (using monthly average temper-
atures; see Breiling et al 1997) and a very costly
approach (using complex snow models), using a data
set based on daily average temperatures (see section on
snow reliability below).
Factors influencing the diffusion
of snowmaking
In preparation for the winter season of 2006–2007 the
Tyrolean ski industry invested EUR 55 million
(US$ 80 million) in snowmaking, with EUR 270 mil-
lion (US$ 396 million) in overall investments (Tiroler
Tageszeitung 2006), although the preceding winter
seasons had delivered enough snowfall even at lower
Winter tourism is high-
ly sensitive to climate
change. The suffi-
ciently studied altitu-
dinally dependent line
of natural snow relia-
bility is losing its rele-
vance for skilift opera-
tors in Austria, where
59% of the skiing
area is covered by
artificial snowmaking. But the diffusion of snowmaking
facilities cannot be monocausally linked to climate
change, as trends in tourism, prestige, and competitive
advantage are important factors. Despite the fact that
snowmaking is limited by climatological factors, skilift
operators trust in technical improvements and believe
the future will not be as menacing as assumed by
recent climate change impact studies. The aim of the
present study is to define reasons for the diffusion of
snowmaking systems and to determine whether snow-
making can be a viable adaptation strategy despite
ongoing warming, using a simple degree-day model.
Results with this method of assessing technical snow
reliability show that current snowmaking intensity will
not be sufficient to guarantee the desired 100-day sea-
son at elevations below 1500–1600 m. Snowmaking
will still be possible climatically even at lower eleva-
tions, but the required intensification of capacity will
lead to significantly higher operation costs.
Keywords: Snowmaking; ski tourism; climate change;
Alps; Austria.
Peer-reviewed: May 2008 Accepted: August 2008
Snowmaking and Climate Change
Future Options for Snow Production in Tyrolean Ski Resorts
Robert Steiger and Marius Mayer
292
Mountain Research and Development Vol 28 No 3/4 Aug–Nov 2008: 292–298 doi:10.1659/mrd.0978
Research
293
elevations. This indicates, first, that although the oper-
ators perceive climate scenarios as often too vague and
unclear, they are well aware of climate change and are
searching for adaptation strategies (Wolfsegger et al
2007). Second, medium-term investment strategies are
not adapted, as there is much confidence in the miti-
gation capabilities of snowmaking technology as well
as an obvious perceivable gap between climate trends
and economic investment cycles (Mayer et al 2007).
Third, while the bad winter seasons at the end of the
1980s sparked snowmaking in Tyrol, further diffusion
was not linked to climate variability and climate
change scenarios.
The recent trend of equipping even naturally snow-
reliable ski runs in high alpine regions above 2000 m,
or in some cases 2500 m ,with snowmaking facilities
cannot be explained by deteriorating snow conditions;
these altitudes can be considered as naturally snow reli-
able even in pessimistic climate change scenarios
(Abegg et al 2007; Mayer et al 2007). Thus, there must
be other reasons for the diffusion of snowmaking: it can
be explained by a widely diverse range of contexts of
justification and general conditions (Figure 3). Pröbstl
(2006) sums up 4 “dominant motivations for the phe-
nomenal diffusion of snowmakers:” snowmaking should
guarantee tourist capacity utilization (ie the tourism
industry as a whole), cable car companies’ incomes, and
images of destinations in which international ski com-
petitions take place. It should also assure general condi-
tions for training and exercise of winter sports (eg
World Cup). These points however, cannot explain the
current situation, as they do not take into account the
consequences of global warming, general trends in
tourism, and their resulting impacts.
Furthermore, modes of snowmaking must be differ-
entiated according to time (season, duration), altitude,
covered surface, and intensity:
•Base layer snowmaking (Grundbeschneiung): can be
defined as “the first area-wide snowmaking of a ski
season, mostly started between mid-November and
beginning of December” (Pröbstl 2006). The reasons
FIGURE 1 Ski areas, snowmaking coverage, and altitudinal distribution of ski slopes in Tyrol. (Map by R. Steiger)
Robert Steiger and Marius Mayer
Mountain Research and Development Vol 28 No 3/4 Aug–Nov 2008
294
for base layer snowmaking (Figure 4) are the follow-
ing: seasonal opening of the operations has to be
scheduled in economic terms (marketing plan,
events, seasonal labor). But the variability of precipi-
tation conflicts with such scheduled openings.
Declining snow reliability at lower altitudes (Mayer
et al 2007, pp 169–170) is another reason for the dif-
fusion of basic snowmaking.
•Snowmaking on all ski runs of a resort (Komplett-
beschneiung): means that all groomed slopes can be
covered artificially, simultaneously or successively. In
the case of large ski resorts, every skilift has at least
one artificially covered ski run. The driving force is
the operators’ and guests’ pursuit of snow guarantee
on schedule, which is in turn determined by two
background variables: the competition of ski resorts
to outperform each other and the global tourist
trend of man-made attractions, which demands a
guarantee of variables such as snow or sun (Job 2005,
pp 128 ff). Thus complete snowmaking coverage is
indispensable for marketing and image creation at a
winter sport destination.
•Snowmaking in high-altitude regions: the opera-
tors’ goals are the following: an early opening of
the winter season with the greatest possible reliabil-
ity, use of costly skilift infrastructure, and improved
quality of ski runs on stony high alpine grounds.
Relevant examples include Hochgurgl (Austria, up
to 3080 m) and Val Thorens (France, up to 3000 m,
Figure 4).
•Snowmaking on glaciers: this is done to assure sum-
mer skiing and early opening in September (unique
selling propositions for glacier ski areas). The spec-
tacular tongue retreats and increasing mass losses of
alpine glacier areas since the early 1980s (Zemp et al
2006) are caused by higher melt rates and fewer
snowfall events during warming summers (Haeberli
et al 1999; Weber and Braun 2004). Melting alimen-
tation areas of the ice fields and a lack of snowfall in
summer are supposed to be compensated by snow-
making. But snowmaking is not a realistic option to
preserve entire glaciers from shrinking. Examples of
snowmaking on glaciers in Austria are the Mölltaler
Gletscher/Carinthia (up to 3120 m), the Rettenbach-
ferner/Sölden/Tyrol (up to 3000 m) and the
Stubaier Gletscher/Tyrol (up to 2900 m).
•Expansion of snowmaking intensity: to optimize the
use of periods with low temperatures, the snow out-
put per hour is enhanced, by increased density of
snow guns, higher pump output, and water reserves.
FIGURE 2 Intensive snowmaking enabled the destination of Schladming (745 m) to mitigate the impacts of abnormal warm temperatures
in the winter of 2006–2007. (Photo by Marius Mayer, 17 February 2007)
Research
295
Thus the necessary time for base layer snowmaking is
rapidly decreasing and is now about 50 hours at top-
end resorts.
•Snowmaking on low altitude valley-runs: this is a new
trend since the late 1990s. Since the low altitude
slopes in particular would be affected first by rising
temperatures, it is surprising that extremely low val-
ley runs can nowadays be reliably opened up for
about 3 months—with the help of intensive snow-
making. An example is the Tyrolean Zillertal, where 3
destinations compete to offer the longest artificially
covered valley run (lowest point at 561 m).
•Depot snowmaking/additional snowmaking: the
reserve production serves to fulfill two goals: glacier
ski resorts introduce them (in combination with
snow farming) to enable guaranteed opening as early
as possible in autumn. At normal ski resorts, depots
are needed to assure skiable slopes during warmer
periods, especially during foehn events and warm
periods in spring on sun-exposed slopes, to guaran-
tee skiing until the Easter holidays. Normally 120 to
150% of the amount of snow produced for base-layer
snowmaking is used for depots and additional snow-
making during the season (Pröbstl 2006).
Without a doubt, trends in ski tourism, like the
snowboard and carving boom since the early 1990s
and 2000s, respectively, supplement the general condi-
tions mentioned. These new trends require totally dif-
ferent prerequisites for ski run quality, preparation,
and consistency than, for instance, classical alpine ski-
ing. These sports require a nearly perfect “ski run par-
quet” that is much more reliable and easier to create
with the support of snowmaking (Veit 2002, p 219).
Above all, the competitive economic pressure between
ski resorts fosters the advance of snowmaking: first,
the winter sport industry hopes to become more inde-
pendent of meteorological conditions. Second, to
optimize the utilization of high-tech skilifts with high
fixed costs, the skiing season needs to be assured and
extended to late autumn and early winter. All this
FIGURE 3 Determining factors for the diffusion of snowmaking. (Source: Mayer et al 2007, p 163
FIGURE 4 Base layer snowmaking in Val Thorens, France, above 2300 m, in autumn.
(Photo by François Balzeau, 3 November 2006)
Robert Steiger and Marius Mayer
Mountain Research and Development Vol 28 No 3/4 Aug–Nov 2008
296
shows that the increased use of artificial snow is based
on a complex bundle of economic, touristic, and cli-
matologic considerations and should not be consid-
ered one dimensionally.
Snow reliability
The scientific definition of snow reliability and the
view of ski operators is quite different. Today when
operators talk about snow reliability they think of
their snow guns as being the most important factor.
The 100-day-rule, formulated by Abegg (1996), stated
that ski resorts can be considered as snow-reliable “if,
in 7 out of 10 winters, a sufficient snow covering of at
least 30–50 cm is available for ski sport on at least
100 days between December 1 and April 15.” By ana-
lyzing climate data Abegg (1996) defined a line of
snow reliability for Switzerland, lying at 1200 m today
and rising by 150 m per 1°C warming. This methodol-
ogy was adopted in a recent Organisation for Eco-
nomic Co-operation and Development (OECD) study
(Abegg et al 2007) of the Alps. Taking into account
the different climate regions, actual snow reliability
is considered to be above about 1050 m for the
northern rim of the Alps, and 1500 m for the South-
ern Alps. Unfortunately, snowmaking was not consid-
ered. Being aware of this insufficiency, and motivated
by several North American studies (Scott et al 2003,
2005, 2006), Steiger (2007) developed a method that
incorporates the role of snowmaking as a possible
and effective adaptation strategy for deteriorating
snow reliability in Bavaria. Here the methodology is
applied to Tyrol, using a +2°C climate scenario (time-
line 2021–2050).
Methods
Snowmaking conditions are influenced by temperature
and humidity—if the air is more humid, cooler temper-
atures are needed. The so-called wet-bulb temperature
combines these two climatic factors. With current snow-
making technology snow can be produced starting at
–5°C wet-bulb temperature without chemical additives
(which are currently prohibited in most parts of the
European Alps). In other words, snow can be produced
at an air temperature of –3°C to –4°C and average
humidity (60%). Good snow quality can be achieved
with snow production starting below –6°C at average
humidity (Breiling et al 1997; Steiger 2007). Fliri’s
(1974) climate tables show a strong correlation between
–2°C daily average temperature and –6°C daily mini-
mum temperature. Days reaching the threshold of –2°C
daily average temperature are defined as potential snow-
making days with optimal snowmaking conditions. Fur-
thermore, snowmaking is only considered reasonable if
it can balance out the loss through snowmelt. In order
to assess the effectiveness of snowmaking and the
degree of possible independence from natural snowfall,
the latter is not included in the model.
A simple degree-day model is used to calculate
snowmelt. This model works as follows: the sum of all
positive daily average temperatures (= degree days) is
multiplied by a degree-day factor. This factor
describes the runoff (in mm) per degree day. A value
range of 2–3 mm water equivalent per degree day is
realistic for the research area in winter months
(Steiger 2007). The average density of groomed tech-
nical snow is 523 g/l (Rixen et al 2004, p 419), thus a
1 mm runoff water equivalent means 1.91 mm of melt-
ed snow depth. With these values and factors the nec-
essary extent of snowmaking can be calculated for a
given snow depth. The minimum snow depth for
alpine skiing is 30 cm on grassland and 50 cm in stony
areas with poor vegetation (Abegg 1996). As the den-
sity of artificially produced snow is higher than natu-
ral snow density, 20 cm of groomed artificial snow is
required in order to get an adequate slope. Average
snowmaking systems are able to produce this amount
of snow in 5 days (Steiger 2007). Thus 0.025 days are
required to produce 1 mm of artificial snow (Equa-
tion 1).
A month can be defined as suitable for snowmaking,
if the number of potential snowmaking days is greater
than the required number of snowmaking days. Finally, the
line of artificial snow reliability can be calculated to
compare these results with older studies that do not
include snowmaking. In contrast to Abegg’s (1996) 100
days in 7 out of 10 winters, a stricter threshold for snow-
making is used (9 out of 10 winters), as the snowmaking
facilities should be operable (almost) every year.
Climatic potential for snowmaking in three Tyrolean
climate stations
With these prerequisites, datasets (1971–2000) for 3
climate stations in Tyrol were analyzed: Kufstein 495
m, St. Anton 1275 m, and Patscherkofel 2247 m (see
Figure 1). Monthly varying vertical temperature gradi-
ents were then calculated by inter- and extrapolating
temperature from 500 m to 2400 m.
Today snowmaking can guarantee snow reliability at
elevations above 1000 m (December to February) for
90% of all winters. In a +2°C climate scenario current
snowmaking intensity will not be sufficient below
1500–1600 m (Figure 5). Small to medium sized ski
EQUATION 1 Formula to calculate the required number of snowmaking days
per month, if potential snowmelt is included.
Research
297
resorts, many of which are found at lower elevations
(Figure 1), may face serious problems if climate change
predictions prove to be correct. Especially base layer
snowmaking will be made more difficult, as it needs to
be done in the early winter months: in November the
number of potential snowmaking days at high altitudes
(> 2000 m) will be reduced by 1/3, and lower altitudes
(1000–1500 m) in December.
Increasing snowmaking capacity is the current strat-
egy of ski area operators when preparing for warmer
winters with fewer cold days. The base layer snowmak-
ing has to be completed within 48 hours (Mountain
Manager 2007a, p 81). The line of technical snow relia-
bility declines significantly with rising snowmaking
intensity (Figure 5). The success of resorts like Schlad-
ming (Figure 2) and good skiing conditions—even in
the 2006–2007 season—can be explained by this devel-
opment.
In addition, it can be expected that snowmaking
technology will be enhanced. Prototypes produce snow
starting at –0.5°C wet-bulb temperature (+2°C at 60%
humidity) without chemical additives (Mountain Man-
ager 2007b, p 54). Climatic conditions will not be the
primary limitation to snowmaking, at least not with a
temperature rise of 2°C. The problem ski resorts will
have to face over the next decades is the rising cost of
snowmaking.
Conclusion
Although climate change is one reason, but surely not
the main reason, for the diffusion of snowmaking facil-
ities, technically produced snow is the most-used adap-
tation strategy for extraordinarily warm winter seasons.
Snowmaking is a considerable short- to medium-term
adaptation strategy, not only for high-altitude ski
resorts but also for financially strong year-round desti-
nations at lower elevations, such as Kitzbühel
(762–1995 m). More frequent warm winters will force
ski resorts to intensify snowmaking capacity with conse-
quences for their financial vitality. Already about 27%
of Swiss ski resorts have a poor cash flow (< 5%) and
most do not seem to be independently viable (Seilbah-
nen Schweiz 2006).
Future studies on the impacts of climate change on
winter tourism will have to go into more into detail in
order to assess the possible changes at a regional or
even a local scale. Keeping in mind that there are differ-
ent types of snowmaking over the winter season, the
impact of rising temperatures on these types will vary. As
FIGURE 5 Elevations suitable for snowmaking today and with a projected 2°C warming, with different snowmaking intensities (5, 3, 1
snowmaking days). The range of uncertainty depends on the degree-day factor (2 mm / 3 mm) chosen.
Robert Steiger and Marius Mayer
Mountain Research and Development Vol 28 No 3/4 Aug–Nov 2008
298
the very intense base layer snowmaking being done at
the very beginning of the season is most affected when
snowmaking conditions are at the climatic limits anyway,
it is very likely that the ski season will shorten despite
intense snowmaking. This requires more complex snow
models as well as regional climate scenario data.
As there is little knowledge about the cost effective-
ness of snowmaking investments, an economic analysis
should be carried out t to assess the suitability of this
adaptation strategy for certain ski resorts. Finally, the
most unpredictable field of research is change in
demand and behavioral adaptation (Teich et al 2007).
As rising costs will have to be paid by the consumers,
their potential reactions have to be examined to under-
stand the possible changes in the financial viability of
ski resorts.
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ACKNOWLEDGMENTS
We would like to thank Hubert Job, Dale Forbes, Mar tin Müller, Bernadette
Schauß, and the two anonymous referees for critical reading and insightful
comments.
AUTHORS
Robert Steiger
Universität Innsbruck, Institute of Geography, Innrain 52, 6020 Innsbruck,
Austria.
robert.steiger@uibk.ac.at
Marius Mayer
Julius-Maximilians-Universität Würzburg, Institute of Geography, Am Hub-
land, 97074 Würzburg, Germany.
marius.mayer@uni-wuerzburg.de
