Stable isotopes and gaseous and particulate impurities in polar ice cores

• Main Authors: Boutron, Claude, Jouzel, Jean
• Other Authors: Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Modélisation du Climat et de l'Environnement (LMCE)
• Format: Book Part
• Language: English
• Published: HAL CCSD 1992
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; Antarctic; Greenland; Antarc*; Antarctica
• Online Access: https://hal.archives-ouvertes.fr/hal-03381318; https://hal.archives-ouvertes.fr/hal-03381318/document; https://hal.archives-ouvertes.fr/hal-03381318/file/iaea_jouzel.pdf

International audience Unique information has been obtained during the last few decades on past changes in the climate of our planet through the investigation of oxygen and hydrogen stable isotopes in palaeowaters, especially in successive, well preserved, dated snow and ice layers deposited in the large Antarctic and Greenland polar ice caps. Together with isotopic data obtained from deep ocean sediments, they have provided confirmation that changes in the orbital parameters of the Earth have played a key role in the succession of glacial and interglacial periods. Polar snow and ice cores have also allowed investigation of past and recent changes in the composi­tion of our atmosphere. During the last climatic cycle, there was a close correlation between the atmospheric concentrations of C 02 and CH4 and climate, with the lowest concentration values during the coldest periods, which indicates that variations in the concentrations of greenhouse gases are likely to have contributed to glacial-interglacial climatic changes by amplifying the relatively weak insolation change associated with orbital ‘forcing’. Of particular interest are the snow and ice layers deposited over the past few centuries, especially since the Industrial Revolution. Anthropogenic increases of C 02 and CH4 are well documented both in Greenland and Antarctica. For species with short residence times such as sulphate, nitrate and heavy metals, the anthropogenic effect is mainly observed in Greenland: for Pb, a two hundredfold increase is observed from several millenia ago to the mid-1960s; it is followed by a decrease of seven and a half times during the past twenty years owing to a reduction in the use of lead alkyl additives in gasoline.