Abstract. We present a minimal model for the global carbon cycle of the Earth containing the reservoirs mantle, ocean floor, continental crust, biosphere, and the kerogen, as well as the combined ocean and atmosphere reservoir. The model
is specified by introducing three different types of biosphere:
procaryotes, eucaryotes, and complex multicellular life. During
the entire existence of the biosphere procaryotes are always
present. 2 Gyr ago eucaryotic life first appears. The
emergence of complex multicellular life is connected with an
explosive increase in biomass and a strong decrease in Cambrian
global surface temperature at about 0.54 Gyr ago. In
the long-term future the three types of biosphere will die out
in reverse sequence of their appearance. We show that there
is no evidence for an implosion-like extinction in contrast to
the Cambrian explosion. In dependence of their temperature
tolerance complex multicellular life and eucaryotes become
extinct in about 0.8–1.2 Gyr and 1.3–1.5Gyr, respectively.
The ultimate life span of the biosphere is defined by the extinction
of procaryotes in about 1.6 Gyr.


Thanks to the excellent science blog The Dragon's Tales

Me, I'm partying hearty 'cause as a carbon based unit of the complex multicellular persuasion ah gots just one Gigayear left to go! Those last 4 orbits of the Milky Way will be my last.