Canada's mild winter has caused the longest recent delay in opening the Arctic ice road, essential for diamond mine access and goods transport, highlighting climate change impacts on infrastructure.

Deteriorating conditions on the Mackenzie Valley Winter Road have prompted the Northwest Territories government to close the winter highway for the season.

The winter resupply road between Yellowknife and the Northwest Territories' three working diamond mines has succumbed to this week's warm weather.

A late start means the community of just over 130 must rely more heavily on air transport, which adds to the cost of goods brought in town.

Construction is beginning today on the ice road connecting Yellowknife to Dettah on the N.W.T.'s Yellowknife Bay, but a warm November means that it will open in January for the second time since the 2006/2007 season, and the second year in a row.