Flooding. We call it a natural disaster. But humans have a role. How do people promote flooding by cutting trees, draining wetlands, paving parking lots and otherwise interfering with nature?

How bad is the asteroid threat to Earth, and what are they doing to find any killer asteroids out there? Read the delightful debate between the no-problem and the killer-asteroid schools of thought.

What causes avalanches? Why are they so dangerous, and how can you avoid them without cowering at home?

New searches are finding lots of asteroids. None of them are aimed at us — yet. How much damage have asteroids done in the past?

As coastal populations continue rising around the world, we wonder about the history of tsunami assaults on humans. What causes these titanic waves, and what can we do to reduce their deadly impact?As coastal populations continue rising around the world, we wonder about the history of tsunami assaults on humans.

Consider the tick. This parasitic insect lives a revolting life, sucking blood from mammals for a living and carrying pathogens that cause illness — Rocky Mountain spotted fever, Lyme disease, and now human granulocytic ehrlichiosis (HGE). You just can’t say anything nice about ticks.