Claude Lorius, a glaciologist who proved the role of human beings in global warming, passed away on March 21 at the age of 91. During his lifetime, Lorius led 22 expeditions to Greenland and Antarctica, where he lived at intervals. He is popular for his study on air bubbles trapped in ice, which was published in 1987 and showed that concentrations of carbon dioxide increased significantly after the Industrial Revolution as temperatures rose. Lorius’ research helped raise awareness of the need to take action on climate change. He was the inaugural expert of the United Nations Intergovernmental Panel on Climate Change in 1988 and was the first Frenchmen to be honoured with the Blue Planet Prize.