The Greenland ice sheet is basically a giant ice cube the size of Alaska. What happens when it melts? We spent five days camping out on the ice with a team of scientists who are trying to find out.

How did we go from more than 50 million wild bison in the United States to just 23 free-roaming animals today? And how does the decimation of the herds relate to the oppression of Native Americans?

We continue our reporting from Kaktovik, Alaska—the only town within the Arctic National Wildlife Refuge—to find out how the conflict over drilling for oil in the refuge feels to the people who live there. The more we listened, the more we realized: the heart of the issue isn’t just over oil extraction and development, wilderness and wildlife. Whatever side people took, their focus is on their community, sovereignty, and survival.

The Gwich’in have lived and hunted in the Refuge long before it was carved out as federal, protected land. Their territory spans a huge swath of northeastern Alaska and northwestern Canada, and their health and culture depends on the Porcupine caribou herd—a group of animals 200,000 strong that calve on the area of the coastal plain slated for drilling.

In this two-part episode, spend time in Arctic Village, a community just over the southern border of the Refuge, and hear from the Gwich’in about what’s at stake for them as development looms in the 1002 area.

An eight-ton concrete ball and a 32,000-year-old needle collection. What's all this got to do with the climate change in Arctic? Find out on this episode of Threshold.

Many cattle ranchers view wild bison as a threat to their livelihoods. But some think cattle and bison can coexist. In this episode, you'll meet two cattle ranchers with different perspectives on wild bison.

We'll also take you on a controversial bison hunt happening at the boundary of Yellowstone National Park.