it is going to read the opening couple of paragraphs to "in the shadow of the sabertooth." for the past 12,000 years the world has enjoyed a relatively stable climate. now the time of predictable global weather has ended. the feature will be unsettled, probably terrifying. forces have been unleashed and threaten the future where children. consequences of global warming have already settled over much of the planet or did a couple of years ago. we probably stronger language today. has this ever climate -- this climate change ever challenged humans before? it certainly has most recently with your north america when people first colonized this continent. 50,000 years ago it did begin to warm melting the huge glaciers they caved off of the icebergs and cause the ocean to rise. the americas were probably an inhabited by people than a teeming with gigantic and fierce animals. many capable of killing and eating human beings. in this brand-new landscape all the lives occupied regions human would explore and earth people somehow adapted to unfamiliar habitat and dangerous creatures in