A new study using evidence from a highly detailed ice core from West Antarctica shows a consistent link between abrupt temperature changes on Greenland and Antarctica during the last ice age, giving scientists a clearer picture of the link between climate in the northern and southern hemispheres.Greenland climate during the last ice age was very unstable, the researchers say, characterized by a number of large, abrupt changes in mean annual temperature that each occurred within several decades. These so-called “Dansgaard-Oeschger events” took place every few thousand years during the last ice age. Temperature changes in Antarctica showed an opposite pattern, with Antarctica cooling when Greenland was warm, and vice versa.