  Many papers and monographs were written about the modeling the Earth climate
and its variability. However there is still an obvious need for a module that
presents the fundamentals of climate modeling to students at the undergraduate
level. The present educational paper attempts to fill in this gap. To this end
we collect in this paper the relevant climate data and present a simple zero
and one dimensional models for the mean temperature of the Earth. These models
can exhibit bifurcations from the present Earth climate to an ice age or a
"Venus type of climate". The models are accompanied by Matlab programs which
enable the user to change the models parameters and explore the impact that
these changes might have on their predictions on Earth climate.
