"Our use of energy has been increasing ever since we discovered and mastered fire and developed agriculture, but mostly since we gained access to a vastly increased energy supply by extracting millions of years of stored and concentrated solar energy from the Earth’s crust in the form of fossil fuels. Combined with the development of new energy conversion techniques, this energy bonanza made it possible to lift the secular barriers to human population and output growth. The new energy sources, forms and uses that came online since the turn of the 19th century gave us access to more materials and enabled the invention of new and increasingly sophisticated exosomatic instruments (i.e. machines), which in turn made it possible to access ever more energy and matter and to transform them ever more effectively and efficiently. This resulted in a rapid rise in our total energy and material “throughput” (i.e. the flow of raw materials and energy from the biosphere’s sources, through the human ecosystem, and back to the biosphere’s sinks), which is what we commonly measure through the proxy concept of “economic growth”. This rise never stopped since then, even if the global distribution of the flows of energy and material inputs, outputs and wastes evolved over time. Our efforts to increase the “energy efficiency” of our machines and processes (i.e. reducing the amount of energy needed to perform certain tasks) never resulted in a reduction of the total energy we used, but on the contrary only contributed to create more room for increasing the rate of our consumption."