Despite the creation of protected areas in the Amazon and other tropical regions, rain forests worldwide are still being destroyed for a simple reason: They are worth more cut down than standing. But with deforestation now a leading driver of global warming, a movement is growing to pay nations and local people to keep their rain forests intact.

The international commission charged with protecting the giant bluefin tuna is once again failing to do its job. Its recent decision to ignore scientists’ recommendations for reducing catch limits may spell doom for this magnificent and endangered fish.

In the last eight years, vast areas of offshore Alaska have been opened to oil drilling. Now, a conservationist argues, the Obama administration must reverse the Bush-era policies if the state is to avoid irreparable harm to Arctic wildlife and to some of the most biologically productive waters on earth.

Scientists have been trying to identify the cause of a cancer epidemic that is wiping out Australia’s Tasmanian devils. Now new research points to an alarming conclusion: because of the species’ low genetic diversity, the cancer is contagious and is spreading from one devil to another.

The commitment by Wal-Mart, McDonald’s, and other major companies to buy only sustainably-caught seafood is an encouraging sign in an otherwise bleak global fisheries picture. After decades of government inaction and ineffective consumer campaigns, corporate pressure may finally be starting to turn the tide on reckless overfishing.

With food prices skyrocketing and climate change looming, the world needs a green revolution like the one a generation ago. But many valuable seed varieties have been lost ”“ and scientists now are scrambling to protect those that remain before they vanish down the genetic drain.

With the support of Gov. Sarah Palin, mining interests have defeated an Alaska ballot measure that could have blocked a huge proposed mining project. Now, plans are moving forward to exploit the massive gold and copper deposit at Bristol Bay, home of one of the world’s greatest salmon runs.

Paul Ehrlich still believes that overpopulation imperils the Earth’s
future. But the good news is we are approaching a demographic turning
point: Birth rates have been falling dramatically, and population is expected to peak later this century — after that, for the first time in modern history, the world's population
should actually start to decline.

President Bush is urging Congress to open the U.S. coasts and the Arctic National Wildlife Refuge to oil and gas drilling. But America must ultimately wean itself off fossil fuels. The question is whether it makes the transition now — or waits until every last one of its unspoiled places has been drilled.

With soaring prices for agricultural goods and new demand for biofuels, the clearing of the world's largest rain forest has accelerated dramatically. Unless forceful measures are taken, half of the Brazilian Amazon could be cut, burned or dried out within 20 years.

As the public seeks answers about the future impacts of climate change, some climatologists are growing increasingly uneasy about the localized predictions they are being asked to make.

Paleontologists and geologists are looking to the ancient past for clues about whether global warming will result in mass extinctions. What they're finding is not encouraging.

The world's greatest lake, holding 20 percent of the planet's surface fresh water, has long remained one of the most pristine places on earth. Now, as Russia's economy booms and its climate warms, the Siberian lake faces new threats.

The burgeoning amount of carbon dioxide in oceans is affecting a lot more than coral reefs. It is also damaging marine life and, most ominously, threatening the future survival of marine populations.

By taking bits of a single gene, scientists are using DNA barcoding to identify new species. If a portable hand-held scanning device can be developed, one ecologist says, it could “do for biodiversity what the printing press did for literacy.”