To rise above tree line is to go above thought, and after, the descent back into birdsong, bog orchids, willows, and firs is to sink into the preliterate parts of ourselves.

Walking is also an ambulation of mind.

In 2007, I received a National Geographic Expeditions Council grant to go around the top of the world and talk to Arctic people about how they've been impacted by climate change.

People travel and hunt on the sea ice - in Alaska, they hunt in skin boats for bowhead whales; in Greenland, they hunt with dogsleds. The ice is their highway. The ice is also the ecosystem in which marine mammals and terrestrial animals such as polar bears exist.

History is an illogical record. It hinges on nothing. It is a story that changes, and has accidents, and recovers with scars.

There is nothing in nature that can't be taken as a sign of both morality and invigoration.