A new study says glaciers in the Antarctic Peninsula have been melting over the past 50 years, and that retreat has accelerated in the past five years. We look at the severity of climate change from the Antarctic to the Arctic, examine climate data, and find out how climate scientists respond to skeptics.
Elizabeth Kolbert, political correspondent, The New Yorker
Michael E. Mann, professor, Department of Environmental Sciences, University of Virginia
David Vaughan, principal investigator, Glacial Retreat in Antarctica and Deglaciation of the Earth System, British Antarctic Survey, Cambridge, United Kingdom