  The flux transport dynamo, in which the poloidal magnetic field is generated
by the Babcock--Leighton mechanism and the meridional circulation plays a
crucial role, has emerged as an attractive model for the solar cycle. Based on
theoretical calculations done with this model, we argue that the fluctuations
in the Babcock--Leighton mechanism and the fluctuations in the meridional
circulation are the most likely causes of the irregularities of the solar
cycle. With our increased theoretical understanding of how these irregularities
arise, it can be possible to predict a future solar cycle by feeding the
appropriate observational data in a theoretical dynamo model.
