Socio-geochemistry is the science that adds humans to the constituent factors of the earth’s materials circulation system. Of course, the human activities within the system should not be for the purposes of destruction. Even if the actions are unintentional, they cannot be allowed to destroy the system or its constituent factors. Because unintended destruction emerges as a side effect, however, it is difficult to prevent by taking action beforehand. What makes that possible is human wisdom. Humans have learned from past experience and developed a method. The approach is to first take some sort of action when we see any sign of risk even though scientific uncertainty is involved, in other words, to exercise the precautionary principle. Spreading this concept throughout society is one of the goals of socio-geochemistry.