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?

Aftershocks and triggered earthquakes both follow a large earthquake, and they don’t happen at random. Can lessons about the sequence and timing of quakes improve safety?

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?

The “late heavy bombardment” burned out any life that was around 4 billion years ago — or not… Plenty of high temperature bacteria could have survived in deep rocks, says a new study.

Each hour, the ocean dissolves 1 million tons of carbon dioxide from burning fossil fuel. As the water grows more acidic, sound travels further. What will happen to marine mammals, which rely on an exquisite sense of hearing?

Construction matters. Hundreds of millions live and work in houses and schools that will collapse in the next earthquake. Chile and California prove that smart engineering saves lives.

New analysis uses light to distinguish one diamond from another. Technique may help jewelers, but won’t help the battle against the “conflict diamonds” that are fueling wars in Africa.

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…