Former Olympic skier Thomas Grandi delivers a letter from 20 Olympic athletes to Prime Minister Stephen Harper's constituency office in Calgary on Wednesday. (Jeff McIntosh/Canadian Press)

Canada's Winter Olympic athletes are calling on the prime minister to support an agreement on cutting greenhouse gases at the UN conference on climate change in Copenhagen.

Former Olympic skier Thomas Grandi delivered a letter, signed by 20 athletes including Olympic gold medallists Jennifer Heil, Hayley Wickenheiser and Beckie Scott, to Stephen Harper's constituency office in Calgary on Wednesday.

The athletes want Harper to help in the reaching of an agreement on reducing emissions at the summit of international leaders.

"We have written a letter to the prime minsiter, to encourage him to go to Cophenagen and to be a constructive leader, to be a real leader in the talks towards a climate change resolution," said Grandi.

Grandi said he has noticed changes in conditions at ski races, and events being cancelled because of unpredictable weather patterns due to climate change.

"Clearly we have seen changes and there's been a few seasons in the last decade where the whole schedule has been up in the air because there hasn't been snow where traditionally there has been snow," he said.

The athletes warned that outdoor sports, such as skiing and snowboarding, which form so much of Canada's winter heritage are being threatened.

Grandi said effects of global warming include fewer skiing days and a shorter Winterlude, the popular winter festival in Ottawa.

"With the Olympics in Canada, in Vancouver, I think Olympic athletes hold a powerful voice," he told reporters.

Sara MacIntyre, Harper's associate press secretary, said the prime minister's office had no comment on the letter.