The idea of creating biochar by burning organic waste in oxygen-free chambers — and then burying it — is being touted as a way to cool the planet. But while it already is being produced on a small scale, biochar’s proponents and detractors are sharply divided over whether it can help slow global warming.

As head of a new energy office at the Pentagon, Sharon Burke is charged with finding ways for the U.S. armed forces to cut its dangerous reliance on oil. In an interview with Yale Environment 360, she talks about what new technologies are being tested and why the military considers energy use a key strategic issue in the field.

Long a proven technology in Europe, green roofs are becoming increasingly common in U.S. cities, with major initiatives in Chicago, Portland, and Washington, D.C. While initially more expensive than standard coverings, green roofs offer some major environmental — and economic — benefits.

The synthetic chemical, BPA — found in everything from plastic bottles to cash register receipts — is a potent, estrogen-mimicking compound. In an interview with Yale Environment 360, biologist Frederick vom Saal harshly criticizes U.S. corporations and government regulators for covering up — or ignoring — the many health risks of BPA.

As the economies of China and other Asian nations have boomed, demand for shark fins — a prized delicacy — has soared, leading to severe overfishing of many shark species. In an interview with Yale Environment 360, shark conservationist Sonja Fordham talks about the battle to save one of the world’s most magnificent fish.

With an aggressive campaign focused on advertising, lobbying, and political contributions, America’s coal industry has succeeded in beating back a challenge from environmentalists and clean-energy advocates. The dirty truth is that Big Coal is more powerful today than ever.

The number of salmon in the Pacific Ocean is twice what it was 50 years ago. But there is a downside to this bounty, as growing numbers of hatchery-produced salmon are flooding the Pacific and making it hard for threatened wild salmon species to find enough food to survive.

By year’s end, regulators are expected to approve a host of solar energy projects in California that could eventually produce as much electricity as several nuclear plants. In an interview with Yale Environment 360, John Woolard, the CEO of the company that has begun construction on the world’s largest solar-thermal project, discusses the promise — and challenges — of this green energy boom.

The sludge spill in Hungary dominated world news for days, as horrific images of red-mud rivers appeared nonstop on the Internet, newspaper front pages, and TV screens. Yet other environmental threats — less visible, but potentially more devastating — often go largely unnoticed.

Climate policies that require public sacrifice and limiting economic growth are doomed to failure. To succeed, policies to reduce emissions must promise real benefits and must help make clean energy cheaper.

Will electric cars one day become part of a network of rechargeable batteries that can help smooth out the intermittent nature of wind and solar power? Many experts believe so, pointing to programs in Europe and the U.S. that demonstrate the promise of vehicle-to-grid technology.

The U.S. has invested billions of dollars trying to create a controlled form of nuclear fusion that could be the energy source for an endless supply of electricity. But as a federal laboratory prepares for a key test, major questions remain about pulling off this long-dreamed-of technological feat.

How significant would it be if America’s 29 million small businesses increased their energy efficiency and reduced their emissions? Judging from the example of one California entrepreneur, the impact could be far greater than you might expect.

Energy companies are rushing to develop unconventional sources of oil and gas trapped in carbon-rich shales and sands throughout the western United States and Canada. So far, government officials have shown little concern for the environmental consequences of this new fossil-fuel development boom.

Last spring, conservation groups and timber companies signed an historic agreement to protect a large swath of Canada’s boreal forest. In an interview with Yale Environment 360, the Pew Environment Group's Steven E. Kallick, a key player in the agreement, explains why the accord is integral to a larger plan to eventually preserve half of Canada’s extensive boreal forests.

When officials gather for an international summit on biodiversity next month, they might look to remind the world why species matter to humans: for producing oxygen, finding new drugs, making agricultural crops more productive, and something far less tangible — a sense of wonder.

Across the Far North, populations of caribou — an indispensable source of food and clothing for indigenous people — are in steep decline. Scientists point to rising temperatures and a resource-development boom as the prime culprits.

One of the more contentious issues facing climate scientists is whether rising ocean temperatures will cause more frequent and powerful hurricanes. In an interview with Yale Environment 360, Kerry Emanuel, of the Massachusetts Institute of Technology, says that amid the uncertainty, one thing seems likely: an increase in the most potent — and destructive — storms.

Ecuador's Yasuni National Park is one of the most biodiverse places on Earth and is home to remote Indian tribes. It also sits atop a billion barrels of oil. Now, Ecuador and the United Nations are forging an ambitious plan to walk away from drilling in the park in exchange for payments from the international community.

An activist caravan to bring one of Jimmy Carter’s solar panels back to the White House symbolizes the time that the U.S. has lost in developing new energy technologies ”“ and the urgent need for taking action on climate.

The freshwater eel, which spawns in the middle of the ocean, was once abundant in much of the world. But the proliferation of dams, coastal development, and overfishing have drastically reduced eel populations, with few defenders coming to the aid of these fascinating — though still not fully understood — creatures.