A recently proposed model of human population and carbon utilization is reviewed. Depending on parameter values, one of three possible long-term outcomes obtains. 1. Atmospheric carbon, [CO2]atm, and human populations equilibrate at positive values. 2. The human population stabilizes, while [CO2]atm increases without bound. 3. The human population goes extinct and atmospheric carbon declines to...

The 20th century has seen unprecedented growth of the human population on this planet. While at the beginning of the century the Earth had an estimated 1.6 billion inhabitants, this number grew to 6.1 billion by the end of the century, and further significant growth is a near certainty. This paper tries to summarize what factors lie behind this extraordinary expansion of the human population an...

natural climatic conditions in urban areas can be changed by human physical environment. climate as a natural system and city as a human system have close mutual connections. urban population growth and consequent increase in urban physical expansion may lead to intensification in human activities and disturbances in the environment. this contributes to alterations in solar radiation, balance o...

Genetic admixture in human, the result of inter-marriage among people from different well-differentiated populations, has been extensively studied in the New World, where European colonization brought contact between peoples of Europe, Africa, and Asia and the Amerindian populations. In Asia, genetic admixing has been also prevalent among previously separated human populations. However, studies...

At the dawn of this new millennium, the human enterprise is quickly becoming a globally unified one. Yet numerous obstacles and pitfalls remain in the path of a full and fair unification. A substantial fraction of the world’s population is well-off and increasingly connected through trade and communications systems. But an even larger fraction is struggling to make ends meet and is only sketchi...