Chief Bill Erasmus of the Dene nation in northern Canada brought a stark warning about the climate crisis: The once abundant herds of caribou are dwindling, rivers are running lower and the ice is too thin to hunt on. Erasmus raised his concerns in recent days on the sidelines of a U.N. climate conference, seeking to ensure that North America's indigenous peoples are not left out in the cold when it comes to any global warming negotiations. Erasmus, the 54-year-old elected leader of 30,000 native Americans in Canada, and representatives of other indigenous peoples met with the U.N.'s top climate...