Gray wolves once ranged across North America. But by the 1930s, they were nearly extinct — trapped, poisoned and hunted by ranchers, farmers, and government agents. With protection under the 1973 Endangered Species Act, the wolf population rebounded. But wolves lost federal protection in 2011. Now, with hunting permitted in many Western states, the future of this once endangered species may again be in question. Can we live with wolves? "Earth Focus" travels to Montana and Wyoming to find out.

(Earth Focus: Episode 45) The future -- Swedish style. Stockholm's Royal Seaport, a rundown district in Sweden's capital, is set to become a model of energy efficiency. Plantagon, a leader in vertical urban agriculture, has an answer to feeding the mega cities of tomorrow -- urban skyscraper farms. The Stockholm eatery Nyagatan, cuts carbon emissions by going local and organic. Solvatten, a Swedish water purification system that uses sunlight is now being used around the world.

Louisiana still is learning from Hurricane Katrina. Forecasts are dire for Louisiana to experience the second-highest sea level rise in the world. There is a big movement brewing in New Orleans to build adaptive "resilience zones." In Southeast Louisiana, the native peoples of the Isle de Jean Charles have become the first U.S citizens moving within their homeland displaced by climate change.

Populations are dramatically shifting as climate change drives migration. Droughts and floods are driving many people away from their rural, farming communities into big cities. We see how this is manifesting in Mongolia and examine the factors leading to the new community of Haitian people living in limbo at the border between Mexico and the U.S.

This episode features author and illustrator Lynne Cherry's film series "Young Voices for the Planet" about young adults making positive environmental change.

“Vanishing Coral” presents the personal story of scientists and naturalists who are working with local communities to protect coral reefs that are being destroyed by warming seas, pollution, and destructive fishing practices. Featured in the documentary is the President of the Biosphere 2 Foundation Abigail Alling, marine biologist and coral expert Phil Dustan, captain of the Mir research sailing vessel Mark Van Thillo, and Nono Suparno, a leading conservationist in Bali.

Two cities, San Francisco and Freetown, brace for climate change using vastly different methodologies. San Francisco's developers are building expensive real estate on floodplains as officials try to heed expert projections on future sea levels. On the other side of the world, a deadly mudslide caused by torrential rains and deforestation in Sierra Leone shows the consequences of city planning that doesn't take climate change into account.

Led by Buddhist monks, Cambodia's indigenous Chong people protest the construction of a hydroelectric dam. The dam, to be built by the Chinese company Sinohydro, would displace the Chong and destroy their ancestral forest home. Kalyanne Mam documents their plight in her film "Fight For Areng Valley." China is beginning to draw on its religious traditions — Tibetan Buddhism, Daoism and Confucianism — to help address serious environmental challenges as profiled in Gary Marcuse and Shi Lihong's film "Searching for Sacred Mountain." 

There are tens of thousands of chemicals in our air, water, and in the everyday products we use. They are largely unregulated and few are adequately tested for safety. They contribute to disease and are linked to conditions such as asthma, autism, ADHD, diabetes, cancers, infertility, cognitive disorders, obesity, reproductive disorders and birth defects. "Earth Focus" looks at endocrine disruptors, ubiquitous chemicals that affect development, metabolism, fertility and intelligence at extremely low doses and at what measures could be taken to better ensure public safety.

Anticipating future water needs, two regions on opposite sides of the world turn to technology for answers. Western Morocco, near the Sahara Desert, is currently facing unprecedented drought and groundwater mismanagement. But an ancient method of gathering moisture from fog is being taught to 13 villages, allowing people to have a level of local control over their most basic need. In Central Valley, California, the food basket of the world uses nearly 80 percent of the entire state's water supply.

(Earth Focus: Episode 56) Exposure to toxic chemicals affects people in both the industrialized and developing world. Earth Focus looks at how Toms River, a New Jersey town, fought back to save its drinking water from toxic waste dumping by dye manufacturer Ciba Geigy and by Union Carbide. Then, a look at the new film Amazon Gold, which addresses illegal gold mining in Peru and its tragic impact on human health and the environment.

(Earth Focus: Episode 48): With a changing climate, a growing population and anticipated fresh water shortages, our food production must evolve. In this episode of Earth Focus, a look at innovative research that is helping develop new and improved root systems for agriculture in stressed conditions, a new Swedish model for urban agriculture, the use of solar energy to power food production in the Himalayas, and an innovative truck farm in New York City.