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.

Ecuador's Yasuni National Park is one of the most biodiverse places on Earth and is home to remote Indian tribes. It also sits atop a billion barrels of oil. Now, Ecuador and the United Nations are forging an ambitious plan to walk away from drilling in the park in exchange for payments from the international community.

Europe is in the midst of a wind energy boom, with the continent now installing more wind power capacity than any other form of energy. In an interview with Yale Environment 360, the European Wind Energy Association's Christian Kjaer describes his vision of how wind can lead the way in making Europe’s electricity generation 100 percent renewable by 2050.

An activist caravan to bring one of Jimmy Carter’s solar panels back to the White House symbolizes the time that the U.S. has lost in developing new energy technologies ”“ and the urgent need for taking action on climate.

LEED certification has emerged as the green standard of approval for new buildings in the United States. But the criteria used for determining the ratings largely ignore factors relating to human health, particularly the use of potentially toxic building materials.

New technologies, feed-in tariffs, and tax credits are helping propel the small wind industry, especially in the United States. Once found mostly in rural areas, small wind installations are now starting to pop up on urban rooftops.

Many energy experts contend natural gas is the ideal fuel as the world makes the transition to renewable energy. But since much of that gas will come from underground shale, potentially at high environmental cost, it would be far better to skip the natural gas phase and move straight to massive deployment of solar and wind power.

Even after the failure to reach agreement on binding CO2 cuts in Copenhagen last December, the United Nations’ outgoing chief climate negotiator is confident that the world is making progress on global warming. The key, he says, is convincing all nations, particularly developing ones, that tackling climate change is in their long-term economic interest.

As utilities seek to build new nuclear power plants in the U.S. and around the world, the latest generation of reactors feature improvements over older technologies. But even as attention focuses on nuclear as an alternative to fossil fuels, questions remain about whether the newer reactors are sufficiently foolproof to be adopted on a large scale.

A prominent marine biologist says the impacts of the oil gushing into the Gulf of Mexico will persist for years, no matter when the flow finally stops. What’s more, scientist Thomas Shirley says that most of the damage remains out of sight below the surface, as creatures succumb to the toxic effects of the rapidly spreading tide of oil.

As global warming intensifies, demands for human manipulation of the climate system are likely to grow. But carrying out geoengineering plans could prove daunting, as conflicts erupt over the unintended regional consequences of climate intervention and over who is entitled to deploy climate-altering technologies.

The oil slick spreading across the Gulf of Mexico has shattered the notion that offshore drilling had become safe. A close look at the accident shows that lax federal oversight, complacency by BP and the other companies involved, and the complexities of drilling a mile deep all combined to create the perfect environmental storm.

California’s high-tech giants have long used renewable energy to help power their Silicon Valley headquarters. Now, companies such as Google, Adobe Systems, and eBay are preparing for the next step — investing in off-site solar and wind installations and innovative technologies that will supply their offices and data centers with green electricity.

As climate and energy legislation continues to founder in Washington, Senator Maria Cantwell says it’s time for a new strategy. In an interview with Yale Environment 360, Cantwell explains why her bill can avoid the pitfalls of cap-and-trade and win the support of the public.

Despite strong evidence that growing food crops to produce ethanol is harmful to the environment and the world’s poor, the Obama administration is backing subsidies and programs that will ensure that half of the U.S.’s corn crop will soon go to biofuel production. It’s time to recognize that biofuels are anything but green.

After making his fortune with Idealab and a host of technology start-ups, Bill Gross has turned his attention to renewable energy. In an interview with Yale Environment 360, Gross talks about the solar power plant technology his company eSolar is developing and about the future of solar.

The drive to extract and store CO2 from coal-fired power plants is gaining momentum, with the Obama administration backing the technology and the world’s first capture and sequestration project now operating in the U.S. Two questions loom: Will carbon capture and storage be affordable? And will it be safe?

There has been growing talk about a clean-tech race between China and the U.S., often cast in ominous tones. But the quest to develop and implement renewable energy can be one where both nations win.

Few places are as well suited for large-scale solar projects as California’s Mojave Desert. But as mainstream environmental organizations push plans to turn the desert into a center for renewable energy, some green groups — concerned about spoiling this iconic Western landscape — are standing up to oppose them.

For years, the promise and hype surrounding electric cars failed to materialize. But as this year’s Detroit auto show demonstrated, major car companies and well-funded startups — fueled by federal clean-energy funding and rapid improvement in lithium-ion batteries — are now producing electric vehicles that will soon be in showrooms.