Qualitative evidence contained within historical sources provides an important record of climate variability for periods prior to the onset of systematic meteorological data collection. Before such evidence can be used for climate reconstructions, it needs to be converted to a quantitative format. A common approach is the generation of ordinal-scale climate indices. This review, written by members of the PAGES CRIAS working group, provides a global synthesis of the use of the index approach.

The Second German Antarctic Expedition (1911–1912) had problems before it set sail south. Wilhelm Filchner (1877–1957) failed to secure his position as expedition leader. He had the support neither of the scientists and officers on board nor of the scientific community in Germany. However, the scientific results were astonishing considering these unfortunate circumstances. That is an example that bad leadership and successful scientific work are not contradictions.