In the absence of political action to cut greenhouse gas emissions, some scientists are starting to seriously consider schemes to mitigate runaway global warming. But big plans to cool the earth, or geoengineering, pose big questions about how and whether we can responsibly manipulate the earth's natural systems. Host Jeff Young discusses the people and concerns driving the geoengineering debate from Jeff Goodell, author of the new book, How to Cool the Planet.

Some revolutions start on a picket line - Jamie Oliver's Food Revolution starts on the lunch line. The celebrity chef's new TV show confronts America’s obesity epidemic in the least healthy part of the country. Host Jeff Young talks with Oliver about eating well as a matter of life and death.

Living on Earth dips into the mail bag to hear what listeners have to say.

The Convention on International Trade in Endangered Species (CITES) meeting in Doha, Qatar has wrapped up. The outcome was anything but positive for marine conservation--with all measures on sharks, coral and the Atlantic bluefin tuna defeated. Host Jeff Young talks with Susan Lieberman of the Pew Environment Group about what happened at the CITES meeting and about future steps for protecting marine species.

Boston celebrates the national dish of Korea with its first annual Kimchi pickle-off. The pungent spicy cabbage brought out plenty of Korean-Americans, farmers and foodies to indulge in fermentation fervor. Living on Earth’s Ike Sriskandarajah reports.

California officials are putting into effect the most comprehensive climate change measures in the country. But unemployment in the state is over 12 percent and a pushback against the state's major climate law is brewing. As Living on Earth’s Ingrid Lobet reports, supporters are gathering signatures for a fall ballot initiative that would roll back the law.

As Secretary of the Interior under Presidents John F. Kennedy and Lyndon Johnson, Stewart Udall fought to protect the nation's water, air, and land. His unrelenting belief that wilderness needed protection was instrumental in the creation of national parks and the passage of the 1964 Wilderness Act Living on Earth offers this tribute to Stewart Udall.

April 3rd marks the 150th anniversary of the famed Pony Express. Just as that first overland mail delivery was replaced by the telegraph, today's postal service is struggling to stay in business as e-communications become the norm. The USPS is exploring the possibility of eliminating Saturday delivery to save money. Sam Pulcrano, vice president of sustainability for the postal service, explains to host Jeff Young how one day less would affect the USPS’s carbon footprint.