AdvertisementWhen Did Humans Start Shaping Earth's Fate? An Epoch DebateApril 06, 2015Nell GreenfieldboycefacebookEmailHumans have influenced Earth's history for thousands of years, though some scientists count changes of the last two centuries as especially notable. ((Left to right) Universal History Archive/UIG via Getty Images; Hulton Archive/Getty Images; Liszt Collection/Heritage Images/Getty Images; Joint Task Force One/AP)