CNN  —  Editor’s Note: Call to Earth is a CNN editorial series committed to reporting on the environmental challenges facing our planet, together with the solutions. Rolex’s Perpetual Planet Initiative has partnered with CNN to drive awareness and education around key sustainability issues and to inspire positive action. Swedish photographer Christian Aslund is riding a small boat along the coast of Spitsbergen, an island in the Norwegian archipelago of Svalbard. Here, deep into the Arctic