As wild fish stocks continue to dwindle, aquaculture is becoming an increasingly important source of protein worldwide. Now, a growing number of entrepreneurs are raising fish in large pens in the open ocean, hoping to avoid the many environmental problems of coastal fish farms.

Twelve years ago in Kyoto, the world was poised to act on a climate treaty but looked for a clear signal from the United States. Now, with the Copenhagen talks set to begin, the outcome once again hinges on what the U.S. is prepared to do.

A number of biologists are challenging the long-held orthodoxy that alien species are inherently bad. In their contrarian view, many introduced species have proven valuable and useful and have increased the diversity and resiliency of native ecosystems.

Even as the climate science becomes more definitive, polls show that public concern in the United States about global warming has been declining. What will it take to rally Americans behind the need to take strong action on cutting carbon emissions?

Long a ubiquitous part of modern life, plastics are now in everything from diapers to water bottles to cell phones. But given the proven health threats of some plastics — as well as the enormous environmental costs — the time has come for the U.S. to pass a comprehensive plastics control law.

The solar power boom in Germany, Spain, and parts of the United States has been fueled by government subsidies. But now some U.S. states — led by New Jersey, of all places — are pioneering a different approach: issuing tradable credits that can be sold on the open market. So far, the results have been promising.

Over the last century, the intensive use of chemical fertilizers has saturated the Earth’s soils and waters with nitrogen. Now scientists are warning that we must move quickly to revolutionize agricultural systems and greatly reduce the amount of nitrogen we put into the planet's ecosystems.

With skepticism growing about the chances of reaching a climate agreement next month in Copenhagen, Rajendra Pachauri, chairman of the Intergovernmental Panel on Climate Change, says he is “cautiously optimistic” that a treaty can still be signed. But in an interview with Yale Environment 360, Pachauri says the global community may have to move ahead without any commitment from the United States.

As the world warms, how different societies fare in dealing with rising seas and changing weather patterns will have as much to do with political, social, and economic factors as with a changing climate.

Green rankings in the U.S. don’t tell the full story about the places where the human footprint is lightest. If you really want the best environmental model, you need to look at the nation’s biggest — and greenest — metropolis: New York City.

Interfering with the Earth’s climate system to counteract global warming is a controversial concept. But in an interview with Yale Environment 360, climate scientist Ken Caldeira talks about why he believes the world needs to better understand which geoengineering schemes might work and which are fantasy — or worse.

Amid a growing call for reducing atmospheric concentrations of CO2 to 350 parts per million, a group of economists maintains that striving to meet that target is a smart investment — and the best insurance policy humanity could buy.

As humans increasingly encroach on forested lands and as temperatures rise, the transmission of disease from animals and insects to people is growing. Now a new field, known as “conservation medicine,” is exploring how ecosystem disturbance and changing interactions between wildlife and humans can lead to the spread of new pathogens.

In her long career as an oceanographer, Sylvia Earle has witnessed the damage that humanity has done to the Earth’s oceans. But in an interview with Yale Environment 360, she says there's still time to pull the seas back from the brink.

Of the various geoengineering schemes being proposed to cool an overheated planet, one approach — extracting carbon dioxide from the atmosphere using “artificial trees” — may have the most potential. But both questions and big hurdles remain before this emerging technology could be widely deployed.

As the international community focuses on climate change as the great challenge of our era, it is ignoring another looming problem — the global crisis in land use. With agricultural practices already causing massive ecological impact, the world must now find new ways to feed its burgeoning population and launch a "Greener" Revolution.

It has been more than 30 years since a groundbreaking book predicted that if growth continued unchecked, the Earth’s ecological systems would be overwhelmed within a century. The latest study from an international team of scientists should serve as an eleventh-hour warning that cannot be ignored.

The average American produces three times the amount of CO2 emissions as a person in France. A U.S. journalist now living in Europe explains how she learned to love her clothesline and sweating in summer.

The Earth has nine biophysical thresholds beyond which it cannot be pushed without disastrous consequences, the authors of a new paper in the journal Nature report. Ominously, these scientists say, we have already moved past three of these tipping points.

Introduced more than a decade ago, genetically modified crops are now planted on millions of acres throughout the world. But the fundamental questions about them remain — both about their safety and their long-term impact on global food security and the environment.