  A theory is described based on resonant thermal diffusion waves in the sun
that appears to explain many details of the paleotemperature record for the
last 5.3 million years. These include the observed periodicities, the relative
strengths of each observed cycle, and the sudden emergence in time for the 100
thousand year cycle. Other prior work suggesting a link between terrestrial
paleoclimate and solar luminosity variations has not provided any specific
mechanism. The particular mechanism described here has been demonstrated
empirically, although not previously invoked in the solar context. The theory
also lacks most of the problems associated with Milankovitch cycles.
