What the Studies Actually Say
The Climsnow research programme, conducted by Météo-France in partnership with academic climate scientists, is the most systematic published attempt to quantify snow-cover change across French Alpine stations. Its projections are not expressed as vague warnings but as threshold figures tied to specific warming scenarios and specific altitudinal bands — the kind of data that can be, and has been, built into a concession renewal calculation or a snowmaking infrastructure plan.
At the low and mid-altitude stations — those sitting below roughly 1,500 metres — Climsnow finds that snow reliability is already degraded under current conditions and deteriorates sharply under the intermediate warming scenario corresponding to roughly 2°C of global mean temperature rise above pre-industrial levels. For Haute-Savoie, this bears directly on small and medium resorts that the Plan Neige programme of the 1960s never reached: places such as La Clusaz and Le Grand Bornand, which sit at developable altitudes of around 1,000 to 1,400 metres at their base areas, and Semnoz, the ridge directly above Annecy, where the ski area operates at elevations that Climsnow's published figures identify as marginal by mid-century under a mid-range emissions trajectory.
For Isère, the picture at low altitude is structurally similar. Alpe du Grand Serre, operated from the commune of La Morte, had already demonstrated by 2024 what happens when the economic arithmetic at a lower-altitude station stops working: the commune voted to cease operations. Climsnow's figures did not cause that decision, but they describe the climatic logic behind it. The programme's published projections identify the 1,500-metre snow line — the altitude below which natural snowfall is insufficient or unreliable for a viable ski season — as one that shifts upward by roughly 150 to 300 metres across different emissions scenarios by mid-century, with the spread depending on whether global temperature stabilises near 2°C or approaches 3°C.
What the Threshold Means in Practice
The commercial consequence of the threshold is not abstract. Compagnie des Alpes, the largest operator of French ski areas, has stated publicly that altitude is now treated as a core asset quality — a position that Domaines Skiables de France, the industry federation whose headline measure is the skier-day, has reflected in its own seasonal reporting by disaggregating performance figures across altitude bands.
Snowmaking can extend the season at stations where natural cover is marginal, but it is not a complete substitute: it requires water stored in retenues collinaires (hillside storage ponds), energy, and sufficient sub-zero temperatures overnight to produce viable snow. Climsnow's projections carry a further constraint here, because the number of nights cold enough for snowmaking also declines with warming, particularly at lower elevations and in early and late season. The programme's findings on this point are among its most operationally significant, since a station that can no longer make snow reliably in November or March loses the shoulder weeks that often determine whether a season is financially viable.
The figures Météo-France has published through the Climsnow framework are therefore not projections that the industry received with surprise. They are a formalisation, in peer-reviewed and institutionally attributed form, of a snow-line shift that operators at lower-altitude stations across Haute-Savoie and Isère had already incorporated into their planning horizons — quietly, without announcement, in the form of deferred capital expenditure, shortened concession bids, and asset write-downs that the Cour des Comptes has noted in its wider scrutiny of mountain infrastructure spending.
