Top alpine racers including Lindsey Vonn, Mikaela Shiffrin and Federica Brignone have raised alarm over rapidly shrinking glaciers.
They say climate change is already transforming the mountains where they train and compete.
Italy, host of the Winter Games, has lost more than 200 square kilometres of glacier area since the late 1950s.
Glaciers once visible from Cortina have largely disappeared.
The Marmolada, the biggest glacier in the Dolomites, is also melting quickly and could be mostly gone within a decade if warming continues.
Athletes say the impact is clear.
Vonn noted that many glaciers she trained on as a child have vanished.
Shiffrin said skiers have a front-row view of the changes.
Brignone warned the retreating ice is not only a threat to sport but to the planet.
Scientists report an accelerating decline in glacier volume and area.
Loss of ice increases water shortages, mountain hazards and sea-level rise.
Some training sites are already unusable because of rocks, crevasses and meltwater.
Researchers say limiting global warming to 1.5°C could still preserve about 100 Alpine glaciers.
Without rapid emissions cuts, far fewer locations will be able to host future Winter Olympics.
Several athletes are now calling for stronger climate action and an end to fossil fuel sponsorship in winter sports.
They say the decisions taken this decade will determine how much ice – and how much of their sport – survives.
