Global Household Proliferation and Implications for Environmental Sustainability

Since the publication of seminal books such as “An Essay on the Principle of Population” by Thomas Malthus in 1798 and “Man and Nature” by George Marsh in 1864, human population size and growth rate have usually been used as the main ultimate indicators of human demand for resources and human impacts on the environment. While many previous studies have provided important insights into understanding human impacts on the environment, they often explicitly or implicitly assume positive relationships between human population sizes/growth rates and their environmental impacts. With widespread reductions in population growth rates and some national and regional reductions in population sizes, environmental impacts should have declined based on the conventional assumption. To the contrary, however, human impacts on the environment continue to soar. Why? One of the reasons is that the number of households worldwide has been increasing faster than population sizes. Even in nations and regions with declining population sizes, their numbers of households are still increasing substantially. This rapid household proliferation is a result of the reduction in the average household size (number of people in a household) due to societal changes such as increased divorces and reduced multi-generation families. More households require more resources (e.g., land, energy, water) for housing. Smaller households are often inefficient and produce relatively more wastes and pollutants per capita. Integrating insights from multiple disciplines and using data from various sources, this research develops a new framework of human-environment interactions and quantifies the environmental effects of household dynamics at local to global levels.

Selected publications:

Liu, J., G. C. Daily, P. R. Ehrlich, and G. W. Luck 2003. Effects of household dynamics on resource consumption and biodiversity. Nature 421:530-533.

Liu, J., T. Dietz, S. Carpenter, M. Alberti, C. Folke, E. Moran, A. Pell, P. Deadman, T. Kratz, J. Lubchenco, E. Ostrom, Z. Ouyang, W. Provencher, C. Redman, S. Schneider, W. Taylor. 2007. Complexity of coupled human and natural systems. Science 317:1513-1516

Yu, E. and J. Liu. 2007. Environmental impacts of divorce. Proceedings of the National Academy of Sciences 104(51):20629-20634

Peterson, N., M. Peterson, T. Peterson, J. Liu. A Household Perspective for Biodiversity Conservation. Journal of Wildlife Management 71(4):1243-1248; 2007.

Peterson, M.N., X. Chen and J. Liu. 2008. Household location choices: Implications for biodiversity conservation. Conservation Biology 22: 912-921

Lepczyk, A., C. Flather, V. Radeloff, A. Pidgeon, R. Hammer, J. Liu, 2008 Human Impacts on Regional Avian Diversity and Abundance. Conservation Biology.

Liu, J., M. Linderman, Z. Ouyang, L. An, J. Yang, H. Zhang. 2001. Ecological degradation in protected areas: The case of Wolong Nature Reserve for giant pandas. Science 292: 98-101.

Liu, J., Z. Ouyang, W. Taylor, R. Groop, Y. Tan, and H. Zhang. 1999. A framework for evaluating effects of human factors on wildlife habitat: The case of the giant pandas. Conservation Biology 13(6): 1360-1370