(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.

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.

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 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.

(Earth Focus: Episode 46) Between 70-210 million gallons of waste oil are illegally dumped at sea by commercial ships each year. In fish, marine oil pollution is linked to cancers, tumors, reduced growth rates, genetic side effects, and death. It is also toxic to seabirds and marine mammals including whales, sea otters, and dolphins. The new film "Oil in Our Waters" exposes this practice. Film director Micah Fink shares his findings with "Earth Focus" and explains new ways citizens can now help stop illegal oil dumping.

Communities and innovators all over the world are creating new sustainable food sources that are resilient to climate change and growing populations. In Madagascar, we see how villagers are closing off marine areas to allow the fish supply to replenish at a natural pace. In San Diego, California, aquaculturists are exploring open ocean farming as a more sustainable model for the fishing industry.

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.

Whether they are researching the pace of Alaskan glacier melt or measuring the impact of Arctic sea ice changes on our our weather, climate scientists go to some of the most remote areas on Earth to help us understand our environment. The Juneau Icefield Research Program (JIRP) brings scientists and students together annually to study glaciers. Jeff Barbee reports on the 2013 JIRP expedition. Julienne Stroeve of the National Snow and Ice Data Center looks at the impact changes in Arctic sea ice may have on weather patterns.

(Earth Focus: Episode 50) This episode of Earth Focus looks at the dark side of shrimp and smart phone industries. Reports from Thailand, Bangladesh, and Indonesia uncover the brutal exploitation of people and the environment for profit.

Photo:  M. Yousuf Tushar / Flickr / Creative Commons

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.

Los Angeles is one of the biggest biodiversity hotspots in the world, despite its smog, urban sprawl and snarling freeways. At least 20,000 native and non-native plant and animal species are thriving despite human interference, and in some cases because of it. How can people help make urban habitats more welcoming to non-human urban dwellers?

"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.

Thousands of dolphins are killed solely for shark bait each year off the coast of Peru. An upsurge in shark meat consumption in Peru and the rise in the cost of fish bait has helped drive the hunt to as many as 10,000 dolphins killed each year according to some estimates. Jim Wickens documents this illegal practice in an original undercover investigation for "Earth Focus."

Asian elephants, already endangered in Indonesia and Thailand,are threatened further by human encroachment and illegal trade. In Indonesia, just 2,500 Sumatran elephants remain. As their last great forest habitat is being logged to make way for palm oil plantations, elephants are pushed into conflict with local people. In Thailand and Myanmar, an illegal and brutal trade in wild baby elephants is contributing to declining elephant populations.

"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.