Researchers disagree about what the economic costs of climate change will be over the coming decades. But the answer to that question is fundamental in deciding how urgent it is to take action to reduce emissions.

One of the many casualties of the recent U.S. elections was Congressman Rick Boucher, a Virginia Democrat who played a key role in passage of cap-and-trade legislation by the House of Representatives. In an interview with Yale Environment 360, Boucher discusses the bitter failure of the Senate to pass a climate bill and future prospects for tackling global warming.

With the Arctic Ocean heading toward a largely ice-free state in summer, scientists are looking for areas that may help preserve ice-dependent creatures. In an interview with Yale Environment 360, geologist Stephanie Pfirman talks about the need for a refuge north of Canada and Greenland that researchers say could be a kind of Noah’s Ark in the age of global warming.

The Chinese government has begun to make environmental records available to the public, empowering green groups and citizens as they try to force factories — and the Western companies they supply — to comply with the law.

The Cancun conference is being credited with keeping international climate talks alive. But the real potential for bringing emissions under control may lie in a Plan B, with nations acting on their own in moving toward a low-carbon economy.

To offset their own carbon emissions, European companies have been overpaying China to incinerate a powerful greenhouse gas known as hfc 23. And in a bizarre twist, those payments have spurred the manufacture of a harmful refrigerant that is being smuggled into the U.S. and used illegally.

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.

It is a difficult idea to fathom. But the science is clear: Unless we change the way we live, the Earth's coral reefs will be utterly destroyed within our children's lifetimes.

The fringes of the coldest continent are starting to feel the heat, with the northern Antarctic Peninsula warming faster than virtually any place on Earth. These rapidly rising temperatures represent the first breach in the enormous frozen dome that holds 90 percent of the world’s ice.

While the collapse of climate legislation in Congress was a setback for some green businesses, many others are moving ahead with projects to develop renewable energy. One major reason: The clean-tech sector is rapidly growing worldwide, and U.S. companies don’t want to be left behind.

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.

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.

Britain’s new government is proposing radically new energy policies, with a “Green Deal” that would retrofit the country’s woefully energy-inefficient housing stock. In an interview with Yale Environment 360, UK Energy and Climate Minister Greg Barker talks about why an overhaul of the approach to energy is essential for the nation’s future.

Amid China’s seemingly boundless emissions of industrial pollutants, there are signs of hope. Discharges of sulfur dioxide, which causes acid rain, have actually decreased, offering some evidence that China is starting to establish a culture of pollution monitoring and control.

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.

As climate science advances, predictions about the extent of future warming and its effects are likely to become less — not more — precise. That may make it more difficult to convince the public of the reality of climate change, but it hardly diminishes the urgency of taking action.

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.

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.