Final answer:
The total weight of plant species or plant material used as fuel is known as biomass, which includes materials like wood and dried animal feces. Biomass energy, originating from biological materials like plants and animal waste, has been a historic energy source and continues to be significant, especially in developing nations. It is considered a sustainable and carbon-neutral energy option when sourced from waste materials.
Step-by-step explanation:
The total weight of plant species or plant material used as fuel is known as biomass. Biomass includes a wide array of materials, such as wood, plant matter, and in some instances, dried animal feces, all of which can be utilized as fuel. Particularly, when wood is burned, it produces approximately 4 kcal of energy per gram, or about 16 MJ/kg, which is similar to the caloric output of proteins or carbohydrates when consumed.
Biomass energy is derived from organic materials of biological origin and is among the oldest energy sources utilized by humans. It held the position of the world's dominant fuel source until fossil fuels became more prevalent with the Industrial Revolution. In modern times, about 12 percent of the world's energy supply comes from biomass. Notably, biomass remains a primary fuel source in many developing nations and is gaining renewed interest as an alternative energy source in developed countries due to the depletion and rising costs of fossil fuels.
As a sustainable energy option, biomass typically comes from waste materials, such as sawdust from lumber mills or scraps from food processing, which would otherwise decompose. This utilization can help mitigate climate change because the combustion of biomass is considered carbon neutral; it releases an amount of CO₂ equivalent to what was captured during the plants' photosynthesis process. However, sustainability also depends on the source of biomass and its impact on the environment and society.