Polar explorer Will Steger is preparing a quest across northern Canada -- a six-month dog sled adventure that will bring the Arctic into thousands of classrooms. Steger hasn't led a sled dog journey in five years, but but says he came out of retirement because of his concerns about global warming.

Ely, Minn. — The trip begins Dec. 15 in Yellowknife, Northwest Territories - in the heart of a northern Canadian winter. Temperatures hover around 40 below zero. There's more night than day. Six adventurers, three sleds, and 30 dogs on a 3,000 mile journey to the Atlantic Ocean.