Keywords: macro-engineering, maximum human population, thermal environment, environmental thermodynamics, heat pumps, solar energy, solar power, world population
Environmental thermodynamic limitations on global human population
This paper examines, from a thermodynamic point of view, how many people the Earth can support. The maximum human population allowed by the natural earth ranges from 300 million millions to 1,700 million millions and will not exceed 1,300 million millions if an ambient temperature of 300 K is accepted. A further increase in population number is obtained for macro-engineered earth when heat pumps driven by solar energy have to be used in order to allow heat to be evacuated form the living space towards that part of the earth's surface acting as a radiator. Then, the maximum world population ranges between 1,600 and 4,000 million millions for various cases detailed in the paper.