Contemporary human settlements come in many forms and sizes. They include clusters of shelters, farming communities, hamlets with only a few residents, as well as great megacities with more than twenty million people. They are places where sedentary people dwell, live, and work. They are the focus of our considerations in this book.
Life in human settlements comes replete with a wide range of inherited beliefs, attitudes, preferences, myths, and customs. They are the birthing places and most obvious physical manifestation of urbanism, the way of life that characterizes towns and cities. They are ecological phenomenon that function in part through learned cultures, cues, and inducements that persuade or dissuade various individual and group behaviors. They give patterns to human activity by offering rewards of honor, authority, riches, and the like for some behaviors and penalties for others. They may be changed at a whim, for no valid reason at all. Yet it is vital to understand human settlements in a valid, scientific way because our species has now evolved in such a way that collective human behaviors have a dominant influence on climate and the environment (Oldfield et al. 2014).
The capacity for humans to drive global change has evolved largely from an evolutionary legacy of strong social bonds, abilities in technology, cognition, and language. This legacy evolved from the primate family during the long, cool, 2.5 million-year climate era known as the Pleistocene. During this time, primordial human ancestors began to develop cultures. All early cultures were organized around the nomadic life of hunting and gathering. These include the Oldowan culture from 2.4 to 1.5 million years ago in Africa, Choukoutien from 1.2 to 0.5 million years ago in East Asia, and Aurignacian from 50,000 to 20,000 years ago in Western Europe (Avery 2012). During the later Pleistocene, these cultures include Aurignacian from 50,000 to 20,000 bc in Western Europe, Solutrian from 20,000 to 17,000 bc in France and Central Europe, Magdalenian from 17,000 to 10,000 bc in Western Europe, and Natufian from about 14,500 to 11,500 years ago in the Levant .
The archaeological record reveals that our human species, Homo sapiens , first emerged 300,000 years ago. For the vast majority of the time since then, human settlements did not exist. The first settlement-oriented cultures emerged independently in multiple places around the world during the period between approximately 10,000 and 5000 years ago. This is to say that human settlements have existed for only about three percent of the time span during which humans have existed.
Yet despite the slow adoption of settled lifestyles, the proportion of humans who live in permanent settlements and the scale of our largest human settlements have expanded rapidly, especially in the last relatively few generations. Today, the culture of urbanism defines the era of large-scale and highly complex problems and global challenges that face current and future generations. Urbanized human cultures are, moreover, rapidly absorbing and extinguishing hundreds of non-urban human cultures each decade. Indeed, the rapid expansion of urbanized culture has now become a principal driver of profound global change in an era that has been named the Anthropocene. 1 The defining characteristic of this new era is the significant impact of human activity on the Earthâs physical and biological systems, including the potential for severely negative and perhaps even catastrophic global-scale impacts. For example, today the likelihood of employing the mutually destructive power of nuclear weapons continues to increase as population growth, climate change, inequality, and sectarian or ethnic extremism continue to undermine nuclear stability around the world.
To place human settlements in the longer-term, evolutionary perspective of this book, archeologists tell us that Homo sapiens evolved from transitional hominid populations living during the geological epoch known as the Pleistocene. Evidence of creatures with our anatomy has been found in Morocco , at a site called Jebel Irhoud from about 300,000 years ago, or approximately 12,000 generations, though modern human behavior did not appear until many years after that (Richter et al. 2017). By about 30,000 years ago, during the Paleolithic Period, our species was the only hominid alive on planet Earth. By about 7000 years ago, or 280 generations, during the Mesolithic period , some of our ancestors had already built permanent settlements. Examples include Byblos and Sidon in Lebanon, Damascus and Aleppo in Syria, Damaidi and Banpo in China, and Susa in Iran. Approximately 3800 years ago or 150 generations, the sixth Babylonian King Hammurabi wrote his law code in Mesopotamia . Pericles was born at the height of ancient Athens a little over 2500 years ago or 100 generations. Julius Caesar crossed the Rubicon with his troops and marched into Rome about 2050 years ago or only 83 generations. The Black Plague descended upon Europe just over 1100 years ago or only 45 generations. Approximately 400 years or 16 generations ago, the Ido period began in Japan , during which time Japanese society was under the rule of the Tokugawa shogunate and the countryâs 300 regional daimyo. The first truly global network of merchant capitalists emerged about 350 years ago, or about 14 generations. And the use of science to create mass production of goods within the factory system did not begin until about 250 years go or only about ten generations.
The very first modest hamlets emerged approximately 10,000 years ago. Five thousand years ago, the largest city in the world was evidently Memphis , Egypt, with a population of over 30,000 (Chandler 1987). By todayâs standards, technology that supported Memphis was just this side of primitive. Ancient Babylon , in modern day Iraq, is believed to have been the first city with over 200,000 people in about 612 bc. 2 The first city to have exceeded 1,000,000 residents is thought to have been Bagdad by about 775 ce. London exceeded 5,000,000 before 1900 ce, and sometime between 1965 and 1975, Tokyo became the first to have over 20,000,000 residents. Today, the planet has over 20 megacities with populations of over 10,000,000.
In this book, we try to convey the evolutionary processes that have increased the scale and complexity of human settlements. The scale and complexity of human settlements have increased to the point that today the environmental consequences of the settlements we inhabit have altered the very climate of the planet. The effect is so profound that climate scientists have used the Latin word for human to name our new era the Anthropocene.
Today, while just over 50% of the worldâs population lives in the settlements we think of as being cities, this part of the population accounts for about 80% of global gross domestic product (GDP). This extraordinary productivity has been made possible largely by processing fossil fuels and by converting and transporting matter and resources, sometimes over great distances. It is known from Newtonâs law of conservation of mass and energy âthe first law of thermodynamicsâthat no material is created or destroyed in any industrial production process, only changed in form (e.g., ores are pressed into motor vehicles). Moreover, it is known from the law of entropy âthe second law of thermodynamicsâthat all industrial production involves the transformation of high-quality potential energy into low-quality waste energy. Thus, in the processes of producing the material foundations of human settlement systems, and in fulfilling the subsistence needs for their populations, matter is rearranged into the built environment and residuals and energy is transformed. But from the point of view of the physicist, nothing, really, is created or destroyed. It is also known that as populations grow and the growing numbers of people deplete the easily accessible resources, they must turn to less desirable and more costly alternatives and improve the intensity of production by developing new technology and modifying their environments. Among other things, this intensification further increases demand for energy, produces more residuals, and creates the necessity for new forms of organizational problem-solving and new institutions.
Growth in the scale, intensity, and complexity of settlements has also brought increased demand for food, clean water, energy, and resources for such necessities as shelter and urban infrastructure. It has also ensured an increased supply of residuals from production, such as greenhouse gasses from burning fossil fuels . Especially after the rise of mechanization and machine-based production, and the corresponding growth in the percentage of the total population living in urban centers, many cities today are places which put unprecedented levels of demand on natural resources, and produce vast supplies of residuals. Todayâs settlement systems, in short, have hitherto unimagined the levels of industrial throughput (i.e., levels of inputs and outputs moving through industrial production processes).
Throughout the entire period of time from the end of the Pleistocene until the industrial revolution , the activity of Homo sapiens â was never powerful enough to cause major global-wide change. While evidence indicates that massive megafauna extinction during the late Quaternary Period may have been tied to human activity (Sandom et al. 2014), given the primitive state of our technology and the small size of our populations, we did not cause widespread deforestation, overfishing of the oceans, or worldwide extinction of species. Human activity could not possibly have altered the entire planetâs climate. Within the most recent 8â10 generations, however the global-scale effects of human activities have become real and discernable.
When human settlement systems were smaller, less technologically advanced, and less complex, the effects of judgmental error and system failure were, as a rule, less severe. Then, as now, when confronted with a problem, the prevailing perceptions and understandings were still scientifically uninformed. The simple perceptions of individuals and groups allowed them to confidently make changes to their local ecosystems, and to the systems and sub-systems of their settlements. They handled their problems then, as we do today, primarily on an âad hocâ basis, by, in effect, acting to perform a repair service on the world as they experienced it. Most did not recognize that they were not very well equipped to deal with situations that required a clear knowledge of the underlying dynamics of the physical, biological, ecological, social, and other systems in which they were embedded, the things that come into play when actions are taken and changes are made. They were particularly poor at understanding outcomes linked to causes with a long time delay. But because the systems in which they lived were smaller scale and less complex, and the technology less advanced, the effects of acting on the basis of partial representations of poorly understood systems were more localized and tended to be less severe and shorter lived.
The Intended Contribution of This Book
This book contributes to developing a scientific understanding of human settlements so that we can improve the policy and management of urban affairs in the early years of the Anthropocene. There are huge challenges ahead, yet we assert that the same evolutionary principles and patterns of change that have functioned in the past can establish expectations and prescriptions for the future. We do not assert that there is one, single, correct approach on which everyone must agree for describing and explaining the evolution of human settlements in the past. Yet most people who have considered the archaeological, fossil, geological, and historical records agree more or less on the evidence they contain. Most who have taken the time to inform themselves well about anthropology, geography, economics, and history can also agree upon the evidence in terms of factors such as demographics, access to resources, the distribution of wealth and income, the consumption of energy, the forms of institutional structures, and the like. But beyond this, wide-ranging disagreements arise over how to explain and understand where humans have come from and where we are going.
The principles upon which we will consider the evolution of human settlements are basic. For a settlement to grow, it must have access to enough subsistence items for its population to survive. In order to produce enough goods and services for its economic system to grow, it must have resources, such as stocks of energy for power. Prior to the industrial revolution , which we will consider at some length, most of the power for production was biomass and muscle power. After the industrial revolution , the primary source of this power has been the burning of fossil fuels , primarily if not exclusively coal. Fossil fuels brought many and huge benefits such as trucks and automobiles, electric power grids that enable the use of lights in homes and offices at night and keep houses warm in the winter and cool in the summer, and computer banks that support the cloud. They also greatly increased the number of kilocalories of energy used per capita per day (energy flows), along with greatly increased demand on stock energy resources.
Our perspective emphasizes the importance of the cognitive and social dimensions of human life, especially those related to governance. We consider these dimensions in relation to a range of variables including population growth, production and consumption, transportation, technology, energy, resources, residuals from production, commercial networks, and other factors. Changes in such factors are drivers of change in human settlement systems. Recognizing and understanding the interactions between such variables is essential for understanding the growth and decline of human settlements. The ways these variables interact can create problems of organization, communication, and governance that must be solved. In turn, the solutions to these problems can require new and as yet not-invented forms of political regulation, new ways to organize production, and new technology. New myths, meanings, and institutions are sometimes necessary.
Efforts to develop a scientific understanding of human settlements will almost inevitably raise some disagreements. Partially, these are attributable to different assumptions and theories. All theories need to make some simplifying assumptions, and all therefore selectively consider only some of the evidence. All must also use some degree of interpretation of it. Not everyone will agree for instance upon what assumptions to make, or exactly what these assumptions imply in terms of what theories should be used to guide the selection of evidence and its interpretations. Moreover, all explanations must be ...