The term Anthropocene's used by some scientists to describe the most recent period in the Earth's history. It's no precise start date, but may be considered to start in the late 18th century when the activities of humans first began to have a significant global impact on the Earth's climate and ecosystems. This date coincides with James Watt's invention of the steam engine in 1784. The term was coined in 2000 by the Nobel Prize winning atmospheric chemist Paul Crutzen, who regards the influence… (More on Anthropocene)