A number of biologists are challenging the long-held orthodoxy that alien species are inherently bad. In their contrarian view, many introduced species have proven valuable and useful and have increased the diversity and resiliency of native ecosystems.

Although it is a heavily urbanized nation, fully two-thirds of Japan remains woodlands. Yet many of the forests are timber plantations inhospitable to wildlife, especially black bears, which are struggling to survive in one of the most densely populated countries on Earth.

As humans increasingly encroach on forested lands and as temperatures rise, the transmission of disease from animals and insects to people is growing. Now a new field, known as “conservation medicine,” is exploring how ecosystem disturbance and changing interactions between wildlife and humans can lead to the spread of new pathogens.

In her long career as an oceanographer, Sylvia Earle has witnessed the damage that humanity has done to the Earth’s oceans. But in an interview with Yale Environment 360, she says there's still time to pull the seas back from the brink.

As the international community focuses on climate change as the great challenge of our era, it is ignoring another looming problem — the global crisis in land use. With agricultural practices already causing massive ecological impact, the world must now find new ways to feed its burgeoning population and launch a "Greener" Revolution.

The natural landscape of South Korea has been largely re-engineered, with nearly every river damned or forced into concrete channels. Now the government is reviving plans for a mammoth water project that would dredge and develop hundreds more miles of waterways and put added stress on the country's remaining wildlife.

Recent studies show that wildlife in some African nations is declining even in national parks, as poaching increases and human settlements hem in habitat. With the continent expected to add more than a billion people by 2050, do these trends portend an Africa devoid of wild animals?

In the Yaak Valley of Montana, environmentalists have been talking to loggers, snowmobilers and other longtime opponents of wilderness protection about the future of public lands. Their accord is part of a cooperative effort that could lead to the first wilderness-area designation in the state in a quarter century.

Clearing land for cattle is responsible for 80 percent of rainforest loss in the Brazilian Amazon. But with Amazon ranching now a multi-billion dollar business, corporate buyers of beef and leather, including Wal-Mart, are starting to demand that the destruction of the forest be halted.

In a matter of years or decades, researchers believe, animals and plants already are adapting to life in a warmer world. Some species will be unable to change quickly enough and will go extinct, but others will evolve, as natural selection enables them to carry on in an altered environment.

As the International Whaling Commission debates whether to ban all whaling or to expand the limited hunts now underway, recent research has convinced some scientists that the world’s largest mammal should never be hunted again.

The environmental damage caused by mountaintop removal mining across Appalachia has been well documented. But scientists are now beginning to understand that the mining operations’ most lasting damage may be caused by the massive amounts of debris dumped into valley streams.

Wildlife biologists and climate scientists overwhelmingly agree that the disappearance of Arctic sea ice will lead to a sharp drop in polar bear populations. But some skeptics remain unconvinced, and they have managed to persuade the Canadian government not to take key steps to protect the animals.

Researchers throughout the world are working to produce biofuel from algae. But a few are trying a decidedly novel approach: Using an abundant and freely available source — human waste — to make the fuel of the future while also treating sewage.

As Borneo's rain forests are razed for oil palm plantations, wildlife centers are taking in more and more orphaned orangutans and preparing them for reintroduction into the wild. But the endangered primates now face a new threat — there is not enough habitat where they can be returned.

By 2100, the world will probably be hotter than it’s been in 3 million years. In an interview with Yale Environment 360, paleoecologist Anthony D. Barnosky describes the unprecedented challenges that many species will face in this era of intensified warming.

The magnificent creature at the heart of the Greater Yellowstone Ecosystem now confronts two grave perils: the loss of its key food source because of rising temperatures, and increased killing by humans. A renowned grizzly expert argues that it’s time to once again protect Yellowstone’s grizzlies under the Endangered Species Act.

With global warming pushing some animals and plants to the brink of extinction, conservation biologists are now saying that the only way to save some species may be to move them.

With record-setting heat waves, bush fires and drought, Australians are increasingly convinced they are facing the early impacts of global warming. Their growing concern about climate change has led to a consensus that the nation must now act boldly to stave off the crisis.

Two decades after the Exxon Valdez spilled 11 million gallons of crude oil into Alaska’s waters, the Prince William Sound, its fishermen, and its wildlife have still not fully recovered.