Seven Deadly Disasters

Seven Deadly DisastersIn the wake of December's indonesian tsunami, what does mother nature have in store for us next?Richard Alley is a geologist at Penn State University. In his office he has a graph that shows the earth's climatic history for the past 100,000 years. The graph reveals that for the first 92,000 of those the global thermometer roller coastered in and out of ice ages and hot spells. The turmoil leveled off about 8,000 years ago into a period of anomalous calm, one that's still wi...