Forecasting what the Earth’s climate might look like a century from now has long presented a huge challenge to climate scientists. But better understanding of the climate system, improved observations of the current climate, and rapidly improving computing power are slowly leading to more reliable methods.

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.

With high gold prices fueling a global gold rush, millions of people in the developing world are turning to small-scale gold mining. In many countries, including Colombia, miners are putting themselves and those who live nearby at risk by using highly toxic mercury in the refining process.

Norway and other nations have vowed to invest billions of dollars to help preserve Indonesia’s remaining tropical forests. But can foreign involvement stem the tide of graft and uncontrolled logging that has steadily decimated one of the world’s largest areas of rainforest?

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 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.

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.