Chapter 15 looks at both the global population and the Earth's environment, as they are in a complex relationship.
Advances in agriculture, industry, and health have resulted in an unprecedentedly large global population. This population has emerged quickly, historically-speaking, and continues to grow. While some predict that the rate of population growth will decrease, the sociological issues related to large populations will persist.
Conflict theory focuses less on overpopulation and more on the unequal distribution of global wealth. While the world produces many benefits, they are not shared by all. Furthermore, cities, a consequence of population density, are sites of social conflict: poverty and homelessness in the midst of wealth. Feminist theory has shown that greater gender equality leads to declines in population growth, and if inequality continues across the globe, the slowing of population growth will follow. Structural functionalism has asked, as has Malthus, whether the Earth can sustain populations of unprecedented size. While there has not been a predicted 'crisis point', there are still issues about the ability of urban environments to manage social problems. Symbolic interactionism is interested in how people come to know about issues of population increases and who is responsible for the challenges large populations face.
The natural environment is that which stands outside humans and human activity. Humans are nonetheless dependent on the environment, and human behaviour shapes the environment, as seen in pollution, climate change, and the management of natural resources.
Conflict theorists recognize that alongside wealth, the consequences of environmental problems are also unequally distributed. Furthermore, conflicts over natural resources are a product of socioeconomic inequality. Feminist theory looks at how gender equality intersects with environmental stability, both based on principles of cooperation and justice. Structural functionalism looks at how environmental issues stem from the structure of population density and population growth, with difficulties of managing what people use 'in common'. Symbolic interactionism studies not only the environment, but ideas about the environment. Systems of meaning shape ideas of who is responsible for environmental harms and for its protection.
The question remains whether science and technology, with its innovations but also unintended consequences, can manage environmental issues. Similarly, the effect of consumption practices warrants attention, because consumption can 'use up' existing resources, but also be 'green' and exert pressure through boycotts and buycotts.