In an effort to reduce some of the uncertainty the climate community has expended considerable efforts to obtain detailed records of past climates recognizing that the past may hold the key to our futurethe two mile time machine by richard alley tells the captivating story of how one such record reconstructed from the gisp2 core drilled through the more than 3 km thick greenland ice sheet has revealed startling clues about past climates and shattering many of our ideas on how climate . The two mile time machine ice cores abrupt climate change and our future updated edition in the 1990s richard b alley and his colleagues made headlines with the discovery that the last ice age came to an abrupt end over a period of only three years in the two mile time machine alley tells the fascinating history of global climate changes . In the 1990s richard b alley and his colleagues made headlines with the discovery that the last ice age came to an abrupt end over a period of only three years in the two mile time machine alley tells the fascinating history of global climate changes as revealed by reading the annual rings of ice from cores drilled in greenland he explains that humans have experienced an unusually temperate climate compared to the wild fluctuations that characterized most of prehistory. Richard alley one of the worlds leading climate researchers tells the fascinating history of global climate changes as revealed by reading the annual rings of ice from cores drilled in greenland in the 1990s he and his colleagues made headlines with the discovery that the last ice age came to an abrupt end over a period of only three years. The two mile time machinebegins with the story behind the extensive research in greenland in the early 1990s when scientists were beginning to discover ancient ice as an archive of critical information about the climate drilling down two miles into the ice they found atmospheric chemicals and dust that enabled them to construct a record of such phenomena as wind patterns and precipitation over the past 110000 years