We present a simple, deterministic energy-balance model with possible relevance to climatic variations on the time scale of glaciation cycles. The lag between ice-sheet extent and zonally-averaged temperature is modeled as a time delay in the ice-albedo feedback. The model exhibits self-sustained oscillations which are quasi-periodic or aperiodic in character. Fourier spectra of solutions have the features of many paleo-climatic records: peaks of variable height and width superimposed on a continuous, red-noise type background. Abstract We present a simple, deterministic energy-balance model with possible relevance to climatic variations on the time scale of glaciation cycles. The lag between ice-sheet extent and zonally-averaged temperature is modeled as a time delay in the ice-albedo feedback. The model exhibits self-sustained oscillations which are quasi-periodic or aperiodic in character. Fourier spectra of solutions have the features of many paleo-climatic records: peaks of variable height and width superimposed on a continuous, red-noise type background.