The treeless ecosystem of mosses, lichens, and berry plants is giving way to shrub land and boreal forest. As scientists study the transformation, they are discovering that major warming-related events, including fires and the collapse of slopes due to melting permafrost, are leading to the loss of tundra in the Arctic.

In the past dozen years, three new diseases have decimated populations of amphibians, honeybees, and — most recently — bats. Increasingly, scientists suspect that low-level exposure to pesticides could be contributing to this rash of epidemics.

Since the government's collapse after a coup last March, Madagascar's rainforests have been plundered for their precious wood and unique wildlife. But now there are a few encouraging signs, as officials promise a crackdown on illegal logging and ecotourists begin to return to the island.

As wild fish stocks continue to dwindle, aquaculture is becoming an increasingly important source of protein worldwide. Now, a growing number of entrepreneurs are raising fish in large pens in the open ocean, hoping to avoid the many environmental problems of coastal fish farms.

On the eve of the Copenhagen conference, a group of scientists has issued an update on the 2007 report of the Intergovernmental Panel on Climate Change. Their conclusions? Ice at both poles is melting faster than predicted, the claims of recent global cooling are wrong, and world leaders must act fast if steep temperature rises are to be avoided.

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.

It has been more than 30 years since a groundbreaking book predicted that if growth continued unchecked, the Earth’s ecological systems would be overwhelmed within a century. The latest study from an international team of scientists should serve as an eleventh-hour warning that cannot be ignored.

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.

Marine biologist Jane Lubchenco now heads one of the U.S. government’s key agencies researching climate change — the National Oceanic and Atmospheric Administration. In an interview with Yale Environment 360, Lubchenco discusses the central role her agency is playing in understanding the twin threats of global warming and ocean acidification.