Biomass is the broad term given to any form of energy created from materials of biological origin such as wood products, crops, plants or dung. These are known as “traditional” sources of biomass, and the ability to burn such material in a controlled way represents a major turning point in human evolution. There is no consensus among scholars regarding when hominins first began to control fire. Archaeological evidence from present-day Israel points to such use by homo erectus in approximately 790,000 BCE, though that species may have learned how to ignite and extinguish fires much earlier. What is clear is that the ability to control fire—for heat, light, cooking, and management of vegetation—gave homo erectus a major evolutionary advantage over the other primates, allowing them to emerge as the dominant hominid species on the planet. By 400,000 BCE, hominins were constructing hearths, pits or confined areas, surrounded by stones in order to contain campfires, which required fuel. Remains of charred animal bones indicate that such fires were used for cooking, though they were almost certainly used for heat, light, and possibly for ceremonial purposes as well. In addition, the construction of hearths points to some means of social organization; the hearth fire became the focal point for the gathering of people. Indeed, the centrality of controlled fire in our own social organization is captured in the commonly-used phrase “hearth and
home,” which evokes a sense of family and security.
As the Stone Age gave way to the Bronze (ca. 3000 BCE) and Iron (ca. 1200 BCE) Ages, biomass gained a new significance. In addition to fueling fire for heat, light and cooking, an abundant supply of biomass was necessary for the production of metal tools and weapons. Indeed, some scholars view deforestation and the lack of available fuel as the central reason behind the decline of ancient civilizations such as the Minoans of Crete, the Sumerians of Mesopotamia and even the Roman Empire. These theories are not universally accepted, though it is clear that the steady increase in metal production had a substantial ecological impact by leading to significant deforestation.
Wood, and to a lesser extent the other traditional sources of biomass, would serve as an indispensable fuel source. Its presence provided heat and healthier foods, which allowed humans to live in otherwise inhospitable regions of the world. This biofuel reliance ended in the western world when wood was replaced as the dominant fuel source in the late nineteenth century. Although coal had become a popular alternative for industrial and transportation purposes in Europe and North America, biomass would remain a vital source of energy for the world as a whole, well into the twentieth century.