  Before about 500 million years ago, most probably our planet experienced
temporary snowball conditions, with continental and sea ices covering a large
fraction of its surface. This points to a potential bistability of Earth's
climate, that can have at least two different (statistical) equilibrium states
for the same external forcing (i.e., solar radiation). Here we explore the
probability of finding bistable climates in earth-like exoplanets, and consider
the properties of planetary climates obtained by varying the semi-major orbital
axis (thus, received stellar radiation), eccentricity and obliquity, and
atmospheric pressure. To this goal, we use the Earth-like planet surface
temperature model (ESTM), an extension of 1D Energy Balance Models developed to
provide a numerically efficient climate estimator for parameter sensitivity
studies and long climatic simulations. After verifying that the ESTM is able to
reproduce Earth climate bistability, we identify the range of parameter space
where climate bistability is detected. An intriguing result of the present work
is that the planetary conditions that support climate bistability are
remarkably similar to those required for the sustainance of complex,
multicellular life on the planetary surface. The interpretation of this result
deserves further investigation, given its relevance for the potential
distribution of life in exoplanetary systems.
