ABSTRACT
This chapter describes the conditions across the Polar Regions during the Last Glacial Maximum (LGM). The dramatic changes that have occurred across the Polar Regions since the LGM, and the processes that have brought about these changes, were triggered by a combination of changes to Earth's orbit and dynamic feedbacks between the ice sheets, the ocean, the atmosphere, and the solid Earth. The growth of the North American ice sheet will have similarly perturbed atmospheric and oceanic conditions around Greenland. Many of the polar ice sheets were marine-terminating during the LGM, meaning that grounded ice extended into the ocean until an increase in the depth of the seafloor meant that the ice began to float and eventually break off as icebergs. The post-LGM increase in snowfall was facilitated by a decrease in sea ice extent, which meant that the distance to the open ocean – the moisture source for precipitation – decreased.
