Exploiting North America’s largest oil deposit has destroyed vast stretches of Canada's boreal forest, arousing the ire of those opposed to this massive development of fossil fuels. Now those opponents are battling the Keystone XL pipeline, which would pass through environmentally sensitive Western lands as it moves the oil to market.

Now in its seventh year, the EU’s carbon emissions trading system is the only international program designed to use market mechanisms to control CO2 emissions. But critics contend it has done little to slow the release of CO2 and argue that it should be significantly reformed — or scrapped.

Despite soaring rhetoric and some promising proposals, President Obama is repeating the same mistakes that have doomed U.S. energy policy to failure for 40 years. Until Obama and Congress finally put a true price on the fossil fuels America consumes, the U.S. will continue its addiction to foreign oil and domestic coal.

On the anniversary of the Deepwater Horizon explosion, the worst fears about the long-term damage from the oil spill have not been realized. But the big challenge is more fundamental: repairing the harm from the dams, levees, and canals that are devastating the Mississippi Delta and the Louisiana coast.

Three years after unveiling his plan for U.S. energy independence, which won praise from environmentalists for its reliance on wind power, Texas oilman T. Boone Pickens is back with a proposal to convert the U.S. trucking fleet to natural gas. But as his new plan gains traction, questions arise over how green it really is.

With contaminated water from Japan’s crippled Fukushima nuclear complex continuing to pour into the Pacific, scientists are concerned about how that radioactivity might affect marine life. Although the ocean’s capacity to dilute radiation is huge, signs are that nuclear isotopes are already moving up the local food chain.

The world’s worst nuclear reactor mishap in 25 years was caused by a massive natural calamity but compounded by what appear to be surprising mistakes by Japanese engineers. The result has been a fast-moving disaster that has left officials careening from one emergency to the next.

A leading U.S. expert on nuclear energy discusses some of the fundamental failures that led to the intensifying nuclear drama in Japan and looks at what might lie in store for nuclear power worldwide.

The disaster at the Fukushima-Daiichi nuclear power plant has highlighted the importance of nuclear energy to Japan and the power long wielded by the nuclear sector. But that influence now is sure to wane, to the relief of opponents who have fought for years to check nuclear's rapid growth.

Electric cars are finally coming to market in the U.S., but what is the future potential for this much-touted technology? A good way to find out would be to launch demonstration projects in selected U.S. cities to determine if, given incentives and the proper infrastructure, the public will truly embrace plug-in vehicles.

Across the U.S., companies are planning scores of projects to burn trees and wood waste to produce electricity, claiming such biomass plants can be carbon-neutral. But critics contend that combusting wood is not really a form of green energy and are urging a go-slow approach until clear guidelines can be established.

William Reilly led the national commission that investigated the Deepwater Horizon oil spill and says he was struck by the totally inadequate response plans that were in place. In an interview with Yale Environment 360, he talks about why it’s crucial to carry out the reforms needed to prevent future disasters.

To shift the global economy from fossil fuels to renewable energy will require the construction of wind, solar, nuclear, and other installations on a vast scale, significantly altering the face of the planet. Can these new forms of energy approach the scale needed to meet the world’s energy demands?

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.

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.

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.

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.

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.

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.