Astronomy’s heritage, comprised mainly of several million photographic plates (both images and spectra), extends backwards in time for many decades. It constitutes a unique and irreplaceable resource for research into long-term variations. Unfortunately, to date rather few of the plates can be accessed in digital formats and cannot therefore be used in modern research. That lack of use encourages the attitude that ‘old’ data have no value and might as well be destroyed. This Workshop discussed ways and means to avert such threats, and prioritised a list of actions that need to be taken as soon as possible.