The dynamic, evolving Earth, and the mathematical representation of its geochemical changes are the subject of this timely, helpful handbook. Global warming, changes in the ocean, and the effects of fossil fuel combustion are just a few of the phenomena that make the development of geochemical models critical. But what computational methods will help to accurately carry out this task? This new text teaches the methodology of computational simulation of environmental change. The author presents interesting applications of his methods to describe the response of the ocean and atmosphere to the infusion of pollutants, the effect of evaporation on seawater composition, climate change, and many other aspects of the Earth's evolving ecosystem. He also presents simple approaches for solving non-linear systems, calculating isotope ratios, and dealing with chains of identical reservoirs. With creative programs that can be executed on any personal computer, Walker offers earth scientists the techniques necessary to address the key problems in their field.