Population Explosion Gives Way to Household Explosion

According to scientists, decades of worry over population explosion has given way to a new worry: household explosion.

Published in Population and Environment, the first long-term historical look into global household changes was completed by Jianguo Liu, director of the Michigan State University Center for Systems Integration and Sustainability, and former students Mason Bradbury and Nils Peterson. According to the press release announcing their findings, "one large household sheltering many people is giving way across the world to households comprised of fewer people - sometimes young singles, sometimes empty nesters, and sometimes just folks more enamored with privacy."

Liu argues that although population growth has been curbed, the desire for people to live in smaller households is increasing the impact of the current population on natural resources and the environment.

"Long-term dynamics in human population size as well as their causes and impacts have been well documented," said Liu, who is the Rachel Carson Chair in Sustainability. "But little attention has been paid to long-term trends in the numbers of households, even though households are basic consumption units."

More households mean more lumber and building materials and smaller households are less efficient, with environmental impacts spread between fewer people. Between 1985 and 2000, Liu noted that the number of households globally has outpaced population growth.

"Average household size in developed countries declined rapidly from approximately 5 members in 1893 to 2.5 at present, while the rapid decline in average household size in developing nations began around 1987. The number of households grew faster than population size in almost every country and every time," said the release.

"We've documented that the changes we're seeing in household size across the globe essentially doubles the number of homes needed per-capita," Peterson said. "This will put enormous strain on the environmental life support system we rely on, even if we achieve a state of zero population growth."

The researchers point out that with increasing numbers of homes, come more roads, more yards and more commercial development.