Routine applications of geobiology can fall anywhere between identifying biomarkers in aiding petroleum exploration to cleaning up of toxic contamination in soil. However, the basic science of geobiology is directed towards an understanding of the interactions between the atmosphere, the biosphere, the hydrosphere and the lithosphere over the life of earth. This understanding helps us learn from the past about the origin of life, its evolution and its survival as well as predict future trends in the effect of factors ranging from microbes to natural disasters on earth's climate, the effect of environment on ecological systems and the growth or depletion of the diversity of species. This is a fast growing field involving many scientific disciplines and would lead to very fundamental changes in our practical outlook on life.