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?

Carbon tax or carbon trading? As the United Nations gets set for (another!) pow-wow on global warming, policy wonks are focusing on two mechanisms to reduce carbon pollution. Which gets more control at a lower price: carbon tax or carbon cap-and-trade?

How do they form? How do we predict their paths? How can we improve predictions?

Some call it Fall. Some call it spring. But nobody in the Midwest, East Coast or Northern Europe is calling it “winter.” What’s up with our weather?

Measurements show a huge ozone hole. How can this happen? We thought ozone-destroying chemicals were being phased out…

Land use: When it changes, so does the climate! The plow and the thermometer: What relationship?

Farms release airborne, drug-resistant bacteria, and indoor air could be making you sick. More news about the particles we breathe every day.

Evidence from ice cores in Greenland and Antarctica show how fast the climate has changed in the past. In this era of global warming, you can’t count on a slow, gradual, predictable warming.

Tornadoes kill 60 Americans each year. How do we predict tornadoes? How do we make houses safer? Where do tornadoes get their energy?

What was learned on Columbia’s last, tragic mission?