Climate change and the Iditarod

A train carries snow from Fairbanks to Anchorage.

The lead dogs of veteran musher Ryan Redington of Wasilla, Alaska, make their way through Long Lake, Alaska, during the 44th Iditarod.

Iditarod rookie Kim Franklin, center, engages spectators prior to beginning the ceremonial start of the 1,000-mile race in Anchorage.

Dog handler Mark Hibma unloads an Aliy Zirkle team dog prior to the start of the Iditarod Trail Sled Dog Race.

With kids and goods in tow, spectators arrive early for the start of the Iditarod Trail Sled Dog Race in Willow, Alaska.

Iditarod veteran Matts Pettersson of Sweden holds his 16-month-old daughter, Frega, as he prepares to begin the ceremonial start of the 1,000-mile race in Anchorage.

Norwegian musher Dag Torulf Olsen, right, has his sled bag checked by Iditarod Trail Sled Dog Race judge Karen Ramstead prior to the race in Willow, Alaska.