ABSTRACT

The conversion of solar energy by the fundamental process of photosynthesis is the basis for almost all life. Life that is not dependent on photosynthesis has been found in vents in the deep oceans, a signi’cant scienti’c discovery; however, it is of no signi’cant importance for the production and consumption of bioenergy. Of course, humans are also dependent on biomass for food, ’ber, and energy. In terms of the mass of the Earth, the thin layer of biomass is inconsequential, but it is signi’cant in the regulation of the atmosphere and temperature of the Earth. There are three aspects for biomass: overall biomass (which is essentially steady state; growth, storage, decay), food and ’ber (Table 10.1), and bioenergy. In general, around 30% of the primary energy of the world is bioenergy, and in some developing countries, it can be 70-90%. Even in developed countries, the contribution from bioenergy can reach 20% due to a large forest industry, and in some of the developed countries, the contribution of bioenergy has been increasing. It is dif’cult to estimate the percentage of biomass for food, ’ber, and bioenergy in the world, as in the developing world food, ’ber, and sources of bioenergy are grown and traded locally.