Tanzania's Hadza people have lived in tune with nature for 40,000 years, but now they face their greatest challenge. Here's how they're both adapting to and combating climate change -- and how we can all learn from them.

Includes interviews with tribal leader Richard Baalow, Tanzanian legal expert Edward Letaika, and environmentalists Marc Baker of Carbon Tanzania, Matt Brown of The Nature Conservancy, and Gus Silva-Chavez of Forest Trends.

We also examine the evolving nature of REDD+ (Reducing Emissions from Deforestation and Degradation) in the United Nations Framework Convention on Climate Change (UNFCCC) and in the voluntary carbon market.

The Argument For a Price on Carbon: Part One.

Featuring  Harvard Economist and "Climate Shock" co-author Gernot Wagner, with Canadian Prime Minister Justin Trudeau, Chilean President  Michelle Bachelet, and Ethiopian Prime Minister Hailemariam Desalegn, as well as a special appearance by the ghost of Nobel Laureate Milton Friedman.