Global energy use is approximately 140 000 TWh per year. Interestingly, biomass production amounts to approximately 270 000 TWh per year, or roughly twice as much, whereas the official figure of biomass use for energy applications is 10-13% of the global energy use. This shows that biomass is not a marginal energy resource but more than capable of meeting all our energy and food needs, provided it is used efficiently. The use of food in generating energy has been extensively debated, but there is actually no need for it given the comprehensive resources available from agriculture and forestry waste. This book discusses the biomass resources available and aspects like efficient energy use. One way of using energy efficiently is to use waste biomass or cellulosic materials in biorefineries, where production of fibers and products from fibers is combined with production of most chemicals we need in our daily life. Such products include clothes, soap, perfume, medicines etc. Conventional pulp and paper applications, bio-fuel for vehicles and even fuel for aviation as well as heat and power production are covered. The problem with biomass is not availability, but the difficulty to use the resources efficiently without harming the long-term productivity. This book covers all types of resources on a global scale, making it unique. Many researchers from all over the world have contributed to give a good coverage of all the different international perspectives. This book will provide facts and inspiration to professionals, engineers, researchers, and students as well as to those working for various authorities and organizations.