"Centennial time" refers to a period or event that occurs every 100 years. It relates to the concept of celebrating or recognizing something significant that happens once in a century. Full definition
The record may not be fully known but it is known that it contains centennial time scale variablity that the models won't be able to reproduce. (realclimate.org)
The working group on coupled biogeochemical cycling and controlling factors dealt with questions regarding the role of plankton diversity, how ocean biogeochemistry will respond to global changes on decadal to centennial time scales, the key biogeochemical links between the ocean, atmosphere, and climate, and the role of estuaries, shelves, and marginal seas in the capturing, transformation, and exchange of terrestrial and open - marine material. (sciencemag.org)
«The influence of rising oceans is even greater than the overall amount of sea level rise because of storm surge, erosion and inundation,» said Carlson, who studies the interaction of ice sheets, oceans and the climate system on centennial time scales. (sciencedaily.com)