Climate scientists worry about feedbacks, glacial melting, sea level rise, using tax policy to slow warming, and the complexity of climate science. Is it realistic to base our economy on endless growth? What does human behavior tell us about dealing with warming?

Buried charcoal stimulates microbes and plant growth, helping farmers on poor soil. Studies show that charcoal is stable for hundreds of years.

Turkeys got help for 75 years from conservation agencies. Coyotes spread across half the country all on their own. Why have these animals succeeded? How have they changed the environment?

Canada’s oil-drenched sands give it the second-largest oil reserves in the world. Using the “tar sands” pollutes air and water, destroys forests and could cause cancer. Should we leave oil sands alone?

Ultralight aircraft are guiding crane chicks toward Florida wintering grounds. Dangers remain, but it’s a step ahead for Americas’ largest flying bird, once reduced to 21 animals.

Scientists propose 9 limits on human actions: Wrecking ozone, over-using fertilizer, killing species could block key “ecosystem services.” Are there natural limits to fresh water use and pollution?

The ozone layer protects Earth from UV rays: Twenty-two years after a treaty to protect ozone, how is the layer doing? What has happened to the ozone hole above Antarctica?

As Earth warms, should we try huge geoengineering projects to cool the climate? Would adding iron to fertilize ocean plants withdraw enough carbon dioxide to slow warming — or backfire?

A new study finds a surprising number of fish, birds and mammals in the oceans 100 and 1,000 years ago. Can this information help regulators slow the decline of important marine animals?

The feds put out a massive report on American birds, and the #1 source of data is – amateurs! What is the role of amateurs in ornithology? Hint: if you want to survey 800 species on 3.5 million square miles…