For the next three weeks, we’ll bring you bite-sized chunks of science that’ll hone in on how we got to where we are right now -- in the middle of the warmest year that humanity has likely ever experienced -- and where science says we’re headed if we don’t get our act together. This week’s show will focus on the past. And our all-star expert on paleoclimate, Jacquelyn Gill, will help us navigate backwards to place today’s planetary-scale changes in context.