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.

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.

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.

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.

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.

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.

Wal-Mart’s push to develop a sustainability index for the products it carries could prove to be a pivotal moment in the effort to make consumers aware of the environmental impacts of what they buy.

Clearing land for cattle is responsible for 80 percent of rainforest loss in the Brazilian Amazon. But with Amazon ranching now a multi-billion dollar business, corporate buyers of beef and leather, including Wal-Mart, are starting to demand that the destruction of the forest be halted.

The scrubby jatropha tree has been touted as a wonder biofuel with unlimited potential. But questions are now emerging as to whether widespread jatropha cultivation is really feasible or whether it will simply displace badly-needed food crops in the developing world.

Kelly Brownell has long studied the relationship between rising levels of obesity in the U.S. and the way our food is grown, processed, packaged, and sold. In an interview with Yale Environment 360, he discusses the common marketing and lobbying tactics employed by the food and tobacco industries.

In an interview with Yale Environment 360, best-selling author Michael
Pollan talks about biofuels and the food crisis, the glories of
grass-fed beef, and why environmentalists must look beyond wilderness
to sustainability.