"This book describes the energy method, a powerful technique for deriving nonlinear stability estimates in thermal convection contexts. It includes a very readable introduction to the subject (Chapters 2 to 4), which begins at an elementary level and explains the energy method in great detail, and also covers the current topic of convection in porous media, introducing simple models and then showing how useful stability results can be derived. In addition to the basic explanation, many examples from diverse areas of fluid mechanics are described. The book also mentions new areas where the methods are being used, for example, mathematical biology and finance. Several of the results given are published here for the first time."--BOOK JACKET.