He therefore gave his models a series of decade-long tests beginning with the real climatic conditions (level of solar radiation, ocean temperature and so on) on 80 different start dates from 1982 to 2001.
They met in 1984 at a Ben Rosen-Esther Dyson computer conference and started going on "virtual dates" by driving to the same movie at the same time in different cities and discussing it on their cell phones.