In China, millions of tons of waste from livestock farms are causing severe water pollution and massive emissions of methane. Now, some large livestock operators are turning to biogas fuel production in hopes of creating “ecological” factory farms.

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.

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.

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.

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.

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.

The Yangtze has been carved up by dams, used as an open sewer, and subjected to decades of overfishing. Now, Chinese scientists — alarmed by the disappearance of the Yangtze river dolphin and other creatures — are calling for a 10-year moratorium on fishing in the world’s third-longest river.

The Gulf of Mexico’s capacity to recover from previous environmental assaults — especially the 1979 Ixtoc explosion — provides encouragement about the prospects for its post-Deepwater future. But scientists remain worried about the BP spill's long-term effects on the health of the Gulf and its sea life.

As warming intensifies, scientists warn, the oxygen content of oceans across the planet could be more and more diminished, with serious consequences for the future of fish and other sea life.

With 20 percent of the world’s population but just 7 percent of its available freshwater, China faces serious water shortages as its economy booms and urbanization increases. The government is planning massive water diversion projects, but environmentalists say conservation — especially in the wasteful agricultural sector — is the key.

Unearthing photographs of the Himalaya dating back more than a century, mountaineer and filmmaker David Breashears has assembled a powerful visual record of the rapid retreat of the region’s glaciers. By comparing archival photographs from such renowned explorers as George Mallory to photographs taken in the past three years, Breashears has documented the steady disappearance of these great rivers of ice, whose melting will eventually threaten the water supplies of hundreds of millions of people across Asia.

The polar bear has long been a symbol of the damage wrought by global warming, but now biologist Andrew Derocher and his colleagues have calculated how long one southerly population can hold out. Their answer? No more than a few decades, as the bears’ decline closely tracks that of the Arctic’s disappearing sea ice.

The surest sign of a warming Earth is the steady melting of its ice zones, from disappearing sea ice in the Arctic to shrinking glaciers worldwide. Now, scientists are using increasingly sophisticated satellite technology to measure the extent, thickness, and height of ice, assembling an essential picture of a planet in transition.

The images of pelicans and other Gulf of Mexico seabirds drenched in oil have stirred sadness and outrage around the world. But, says conservationist Melanie Driscoll, the unseen effects are probably far greater, with some birds perishing out of sight, far from shore, and others facing spill-related declines in the fish on which they depend.

The massive oil spill in the Gulf of Mexico is a warning, conservationists say, of what could happen in the Arctic as melting sea ice opens the Arctic Ocean to oil and gas drilling. Many experts argue that the time has come to adopt an Arctic Treaty similar to the one that has safeguarded Antarctica for half a century.

For years, free-market fundamentalists opposed to government regulation have sought to create doubt in the public’s mind about the dangers of smoking, acid rain, and ozone depletion. Now they have turned those same tactics on the issue of global warming and on climate scientists, with significant success.

A prominent marine biologist says the impacts of the oil gushing into the Gulf of Mexico will persist for years, no matter when the flow finally stops. What’s more, scientist Thomas Shirley says that most of the damage remains out of sight below the surface, as creatures succumb to the toxic effects of the rapidly spreading tide of oil.

In response to the widening disaster in the Gulf of Mexico, government officials have approved a plan to intercept the oil by building a 45-mile sand berm. But scientists fear the project is a costly boondoggle that will inflict further environmental damage and do little to keep oil off the coast.

Within the planet’s oceans and soils are trillions of bacteria that store and release far more carbon dioxide than all of the Earth’s trees and plants. Now, scientists are attempting to understand how the world’s bacteria will influence — and be influenced by — a warming climate.

Is human activity altering the planet on a scale comparable to major geological events of the past? Scientists are now considering whether to officially designate a new geological epoch to reflect the changes that homo sapiens have wrought: the Anthropocene.

The oil slick spreading across the Gulf of Mexico has shattered the notion that offshore drilling had become safe. A close look at the accident shows that lax federal oversight, complacency by BP and the other companies involved, and the complexities of drilling a mile deep all combined to create the perfect environmental storm.