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 53) It is possible to rehabilitate large-scale damaged ecosystems, to improve the lives of people trapped in poverty and to sequester carbon naturally. John Liu presents "Hope in a Changing Climate," which showcases approaches that have worked on the Loess Plateau in China, Ethiopia and Rwanda. Produced in collaboration with the Environmental Education Media Project (EEMP).

Honey bees, the essential pollinators of many major U.S. crops, have been dying off in massive numbers since 2006. This threatens the American agricultural system and the one in 12 jobs that depends on it. There is growing evidence that a new class of pesticides -- nerve toxins called neonicotinoids, which are used on many U.S. crops like corn -- may be toxic to bees.

"Earth Focus" speaks with Jeremy Monroe about his film "Willamette Futures," which documents the effort to restore the watersheds of Oregon's largest river system. Satirical writer George Wolfe's controversial act of civil disobedience, leading a kayaking expedition down the cemented Los Angeles River, is the focus of Thea Mercouffer's film "Rock the Boat." The expedition sought to have EPA declare the river navigable so that it could gain protection under the Clean Water Act. The boating trip down the L.A.

(Earth Focus: Episode 37) Food and social justice. Human rights abuses, rape and corrupt practices in the Bangladesh shrimp industry. A report by the Swedish Society for Nature Conservation uncovers the human and environmental cost of shrimp farming and shows why buying shrimp from Bangladesh where they are exposed to pesticides and injected with dirty water may be hazardous to your health. UK's The Ecologist investigates the plight of African migrant workers in Italy and looks how financial speculation is threatening the livelihood of Mexican farmers.

(Earth Focus: Episode 41) What do plants, snakes, molds, marine sponges, and cone snails have in common? They have helped develop medicines that save human lives. Biodiversity -- the variety of life on Earth -- is key to human survival. But plants, animals, and microorganisms are disappearing at unprecedented rates. What impact will this have on human health? Find out in this Earth Focus special report produced in collaboration with the Center for Health and the Global Environment, Harvard Medical School.

"Ground Operations," a new film by Dulanie Ellis and Raymond Singer, shows how farming provides both employment and therapeutic recovery for America's combat veterans. Then, meet organic pioneers from Minnesota and Maryland. Also in this episode, a segment showing how California's Pie Ranch develops an innovative way to bring healthy food to a high tech giant while saving a small family business in the process.

The debate over climate change remains polarized. Efforts to discredit the science of climate change by fossil fuel interests are a large part of the reason why says Michael Mann, Distinguished Professor of Meteorology at Penn State University. "If there was a huge industry that would stand to profit greatly if the theory of gravity were wrong you would see the theory of gravity being contested in our US Senate," he tells "Earth Focus" correspondent Miles Benson in an exclusive interview. Mann on the politics of climate change and the impact it has had on both science and policy.

(Earth Focus: Episode 42) A look at the award-winning film "Arise!" and its documentation of the intellectual and spiritual insights that women from around the world bring to solving today's environmental challenges. Mother/daughter filmmakers Lori Joyce, Candace Orlando, and executive producer Molly Ross reflect on the making of the film.

City of the future? A look at Hamburg Germany, Europe's Green Capital 2011. And a future model for business? Vestergaad Frandsen, a Swiss medical textile company pioneers a an innovative new business scheme -- carbon credits for water -- that shows how doing good can be good business.

Africa, a continent facing frequent droughts, is especially vulnerable to climate change. But Africans are finding innovative solutions. Creating a Climate for Change, a new film by Jeff Barbee, takes us on a journey through Southern Africa exploring local people-driven projects that help communities adapt to climate change and restore ecological systems.

(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.

"Going naked" is how the insurance industry describes not having insurance. And when it comes to the worst hazards of nuclear power — America is going naked. Correspondent Miles Benson investigates why the U.S. nuclear power industry is underinsured by hundreds of billions of dollars. He also speaks with Australian physician, author and nuclear industry critic Dr. Helen Caldicott on the health effects of nuclear radiation including cancers, fetal damage and genetic mutation.

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.

After centuries of over-harvesting and bouts of disease, oyster populations in the Chesapeake Bay plummeted along with profits for the oyster industry and the health of the Bay. In some areas, native oysters are becoming more abundant. But culture and ecology clash as watermen, who depend on harvesting oysters for income, are at odds with scientists and conservationists who want to restore oyster populations. Filmmaker Sandy Cannon-Brown looks at oysters and the people behind them in her documentary "Spat! Bringing Oysters Back to the Bay."