The Life and Death of Planet Earth

Professors Ward and Brownlee from the University of Washington wrote a biography of our Planet, "The Life and Death of Planet Earth". Prior to that they wrote "Rare Earth".

For the first time there is scientific knowledge to predict the long term future of the Earth. Astrobiology is a new science, one of of these authors is a biologist and the other an astronomer. Astrophysicists have known for some time now, that stars are born go through middle age and die. In that sense, one should expect that planets go through a life of their own. What is new in this contribution of Ward and Brownlee is the life part of it. Since the 70s James Lovelock presented the idea that our planet is alive, but only until now one can see more clearly how does it happen, and in what sense the Earth is alive.

Ward and Brownlee tell us that one important organ keeping our planet going is the cortex. More specifically the continental plates provide an important service to the complex of interactions that leads these thinkers to consider the life on Earth as an integral part of other more inorganic services that it provides. The motion of continents will reverse course somehow in the next billion years or so, and life will go back also. The thesis is that we are at a peak of complexity, i.e. our Planet is in middle age and already in its way to death.

In "Rare Earth" they argue that plants and animals need the very special conditions on Earth, and it is very unlikely that other planets produce complex life. In this new book, they argue that the amount of time the Earth spends in this high complexity stage is short. Only one or two billion years out of the twelve billion alloted to our Sun and Planet.

It is a little discouraging to say the least, that complex life cannot go for longer. The only way out, the way I see it, is that we start right now to figure out how to extend intelligence life outside of our alloted space, and our alloted time.