There have been many advances in soil chemistry since Oxford published the first edition of The Chemistry of Soils in 1989. The physical-chemistry approach to soil chemistry taken in the book, groundbreaking for its time, has been adopted by nearly every soil chemistry book published since. This book offers a thorough update of all topics covered in the previous edition. In the last 16 years, soil chemistry as a discipline has assumed major significance in connection with global climate change. The 2nd edition addresses the emergent issue of global climate change by exploring the interaction between organic carbon and soil. The largest repository of organic carbon on earth is still soil, and the process by which organic carbon is sequestered by soil, thus preventing the release of carbon dioxide into the atmosphere, is one of the proper concerns of soil chemistry. Thus, the revision provides a rigorous discussion of soil chemistry in its broader environmental and biogeochemical contexts.