Arguably, centennial variability has been the forgotten orphan of climate dynamics theory. In a 1990 paper titled "Three basic problems of palaeoclimate modelling", the late Barry Saltzman presented the centennial timescale as a zone with a variability gap – a demilitarized zone, separating people interested in weather from those interested in the slow evolution of climate.
Crucifix, M., de Vernal, A., & Franzke, C. (2017). Centennial climate change: The unknown variability zone. Past Global Changes Magazine, 25, 133. https://doi.org/10.22498/pages.25.3.133 (Original work published 2017)