An excellent example of the use of magnetic methods and the system approach to reconstruct climate variability in subtropical Africa during the Pliocene and Pleistocene is provided by deMenocal and Bloemendal [in press]. Magnetic-susceptibility records were used in conjunction with several other paleoceanographic methods to reconstruct the long-term record of dust deposition in marine sediments adjacent to Africa. They demonstrated that prior to about 2.8 Ma, high-latitude and low-latitude climate regimes were independent, but that when ice sheets progressively expanded after 2.8 Ma producing increasingly larger climate oscillations, low-latitude climate became dependent on the high-latitude glacial-interglacial cycles. Prior to 2.8 Ma, African climate primarily responded to precipitation changes controlled by monsoon intensity. Monsoon intensity was in turn related to summer insolation variations controlled by orbital precession. Maximum precipitation would occur when summer insolation reached a maximum at orbital perihelion during the boreal summer. After 2.8 Ma, aridity was controlled instead by the high-latitude climate regime including the North Atlantic sea-surface temperature (SST) as well as the size and elevation of the ice sheet. Cold-arid cycles in Africa thus correspond to glacial stages [ deMenocal and Bloemendal, in press]. This study is at present the best example of a major breakthrough in understanding of the evolution of climate achieved by the extensive use of magnetic methods. In addition, this study will impact theories that view African climate change as a causal mechanism for hominid evolution.