Top athletes including Lindsey Vonn, Mikaela Shiffrin and Federica Brignone have raised alarm over rapidly shrinking glaciers during the Winter Olympics in Cortina.
They say warming temperatures are already changing how and where they train.
Glaciers once visible from the host town have largely disappeared.
Major ice now survives only at higher elevations, with the Marmolada melting quickly.
Scientists report Italy has lost more than 200 square kilometres of glacier area since the late 1950s.
Vonn said many glaciers she skied as a child no longer exist.
Shiffrin added that snow-sport athletes witness climate change first-hand on mountain peaks.
Brignone said the retreat of ice worries her more for the planet than for skiing.
Researchers warn the loss has wide consequences.
Glaciers support water supplies, stabilise mountain terrain and influence sea levels.
Some Dolomite glaciers have already shrunk by about one-third in recent decades.
The Marmolada has halved in size in 25 years and could almost vanish by 2034 under current warming trends.
Limiting global heating to 1.5°C could extend its life and save about 100 Alpine glaciers.
Athletes from several nations report shorter seasons, exposed rock and unsafe crevasses on training slopes.
Many now call for stronger climate action and an end to fossil fuel sponsorship in winter sports.
They warn that without rapid emission cuts, the future of both glaciers and the Winter Olympics is at risk.
