At the Great Barrier Reef in Australia, Joshua Jackson investigates the impacts of ocean warming on coral reefs and looks at the predicted impact of ocean acidification. He travels to the Philippines, whose citizens heavily rely on healthy reefs for food and other ocean products and protection from storms. Nikki Reed looks at the best single solution for climate change: putting a price on carbon. She joins activists and interviews the mayor of Vancouver, were carbon pricing has been a success.

In Kenya, Aasif Mandvi explores the threat of climate change poses to endangered species. Drought is compounding poaching and loss of habitat. In Washington, DC, Bradley Whitford looks at the progress of activists like Jay Butera on persuading Republicans to forge bipartisan efforts to act on climate change.

Burning coal remains a major source of energy, emitting toxic pollutants and climate-altering carbon dioxide. In Illinois America Ferrerameets with activists who want to shut down a local coal plant, and with a mayor who want to keep it open. She learns about an option that can provide clean energy and green jobs. Sigourney Weaver investigates China's impact on on today's global environment, and the progress it is making to reduce emissions even as its economy grows.