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.

A decade ago, Nobel Prize-winning scientist Paul Crutzen first suggested we were living in the “Anthropocene,” a new geological epoch in which humans had altered the planet. Now, in an article for Yale Environment 360, Crutzen and a coauthor explain why adopting this term could help transform the perception of our role as stewards of the Earth.

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?

The world’s oceans have been experiencing enormous blooms of jellyfish, apparently caused by overfishing, declining water quality, and rising sea temperatures. Now, scientists are trying to determine if these outbreaks could represent a “new normal” in which jellyfish increasingly supplant fish.

For years, a chemical plant in the Chinese village of Qiugang had polluted the river, poisoned the drinking water, and fouled the air — until residents decided to take a stand. The Warriors of Qiugang, a Yale Environment 360 video co-produced by Ruby Yang and Thomas Lennon, tells the story of the villagers’ determined efforts to stop the pollution.

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 push to promote sustainable palm oil is turning into a test case for green consumerism. The outcome could help determine the future of the rainforests of Asia and Africa — and whether consumer pressure can really sway corporate giants.

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.

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.

In the past century, populations of wild tigers have plummeted from 100,000 to 3,500. Now the World Bank and conservationists have launched an eleventh-hour effort to save this great predator, focusing on reining in the black market for tiger parts and ending the destruction of tiger habitat.

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 large swaths of forest destroyed by wartime defoliants, and even larger areas lost to post-war logging, Vietnam has set an ambitious goal for regenerating its woodlands. But proponents of reintroducing native tree species face resistance from a timber industry that favors fast-growing exotics like acacia.

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.

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.

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.