Historical reconstruction of the earth's past atmospheric environment from Greenland and Antarctic snow and ice cores

Abstract

During the past decades, the investigation of various elements, species, and isotopes in the frozen atmospheric archives stored in the Greenland and Antarctic ice caps for several hundred thousand years has provided a wealth of fascinating information on past and recent changes in the atmospheric environment of our planet. After a brief description of the Antarctic and Greenland ice caps, we give an overview of the procedures that are used in the field for collecting snow and ice from the surface down to great depths. We discuss the techniques used to date and analyse the samples. The main results obtained to date are then presented, with special emphasis on the very recent. The analysis of the snow and ice layers deposited during the past few centuries, especially since the Industrial Revolution, has allowed us to assess clearly the impact human activity has had on the atmosphere, for important constituents such as heavy metals, sulfur and nitrogen compounds, greenhouse gases, carbon and organic compounds, and artificial radionuclides. The analysis of ancient ice up to several hundred thousand years old has provided unique insight on the past natural changes that affected our atmosphere during glacial–interglacial transitions, especially the temperature, greenhouse gases, soil- and sea-derived aerosols, and heavy metals.Key words: Greenland, Antarctica, ice, global pollution, climate change, heavy metals.