Abstract – Polar ice cores – unique archives of global climate and environmental change:
Together with marine and lake sediments, tree rings, corals etc., ice cores represent natural climate archives, which allow us to reconstruct climate and environmental changes in the past.
Apart of their very high temporal resolution (in many ice cores allowing us to resolve individual years or even seasonal cycles) and their long time coverage (the longest ice core records cover the last 800,000 years), ice cores represent the one and only climate archive that enables us to directly measure the atmospheric composition of the past in little air bubbles enclosed in the ice.
Only with the use of ice cores it became possible to quantitatively document the significant increase in atmospheric air pollution and in greenhouse gas concentrations since the beginning of the industrialization. This revealed that recent concentrations of carbon dioxide, methane, and nitrous oxide in the atmosphere have not been encountered anywhere close in preindustrial ice core records over the last 800,000 years.
Ice cores also opened the eyes of climatologists for the occurrence of rapid climate changes during glacial times and their interhemispheric coupling and provide a better understanding of the interaction of climate and biogeochemical cycles in the past and, thus, also in the future.