Just 500 years ago, humans lived in four separate world zones, each with distinct cultures and technologies. Now, humanity is linked within one interconnected network of information and commerce that spans the entire planet.
For most of the past 10,000 years or so, the biosphere has been a fairly stable and predictable place. But data from the last 250 years shows the biosphere is rapidly changing. This new epoch can be called the Anthropocene to reflect the tremendous impact that humans now exert in the biosphere.