  The present nearly exponential growth of the cumulative installation power of
wind and photovoltaic power plants is very promising in the context of a rapid
reduction of the emission of CO2, which can lead to a swift mitigation climate
change if this growth behavior is maintained in the future. In this review we
identify a set of ten limiting factors that can restrain, or halt back, an
exponential growth of these variable renewable power plants (VREs) in the
future. If the exponential growth slows down to a linear growth, such a case
would extent considerably the time to reduce the CO2 emissions and the related
mitigation of climate change. A scenario that would result to a much higher
risk of a future continuation of the economic grow and thrive of the global
economy and human society. We argue that if these limiting factors are
adequately addressed to an exponential expansion VRE power plants is feasible
and can result in the nearly complete avoidance of CO2 emissions as related to
energy generation and consumption in 2030.
