The modern civilization that originated from the Industrial Revolution is now spreading throughout the world. The demand for natural resources is rapidly increasing and the environmental problems are getting globally more and more serious. Our civilization seems hardly sustainable. What should we do to make it sustainable? This series establishes the fundamental theory of civilization, analyzes the problems of resources and the environment in terms of entropy, and suggests a solution to them.

Georgescu-Roegen coined the fourth law of thermodynamics according to which matter continuously and irrevocably degrades from an available to an unavailable state in a closed system including the Earth and predicted that we would soon arrive at the state of maximum entropy, material death rather than heat death. He also insisted that recycling could not avoid this material death, because the ideal of complete recycling is based on the illusion of the thermodynamically impossible perpetual motion. But what he called the fourth law of thermodynamics is false. A closed system such as the Earth can reduce material entropy in exchange for increasing thermal entropy, keeping the former low by dumping the latter in outer space. That is to say, a sustainable economy based on recycling is possible, at least theoretically.

Fuel cells were invented in the 19th century, but their practical application has been extremely limited to date, as thermal power generation has become the mainstream method of power generation. Today, with decarbonization and the hydrogen economy, fuel cells are again attracting attention as a method of power generation using hydrogen. Innovations are necessary for fuel cells to become more practical than they are today, not only in the fuel cells themselves but also in the way of storing and transporting their fuel, as well as in the method of producing it.

Although we intuitively understand what pollution is, its essence is unclear. Without gaining an insight into the concept of pollution, we cannot find a solution to eliminate it. In this article, I first define what pollution is in terms of entropy and then examine the feasibility of material recycling and energy recovery of waste as the solution for waste disposal.

In modern Europe, engineers tried to invent perpetual motion machines, only to fail. Perpetual motion machines are imaginary machines that eternally work without being supplied with any fuel once they are set up. Invention of perpetual motion machines is modern alchemy.