Predicting the future of our Earth and its climate requires models that contain good representations of the key processes that might take place. Our only way to determine what these processes are, and to test the models, is to
look at the past. Numerous “palaeo” [Gk palaios ‘ancient’]
archives exist, ranging from tree rings to marine sediments, but ice cores have played a crucial role in helping us to understand how the Earth works. For example, Greenland ice cores have shown us that extremely rapid climate changes centred in the North Atlantic region are
possible, and that natural changes in concentrations of
greenhouse gases and in climate have been closely linked in the past. Most of what is measured on ice cores is really chemistry. In this article, based on his 2007 ECG DGL, Dr Eric Wolff from the British Antarctic Survey, describes how ice cores work, and summarises some of the key
findings that have emerged from measuring their chemistry.